The Role of Non-Governmental Organizations in Combating Malnutrition in Yemen: A Systematic Review of Interventions, Effectiveness, and Impact (2020-2025)

The Role of Non-Governmental Organizations in Combating Malnutrition in Yemen: A Systematic Review of Interventions, Effectiveness, and Impact (2020-2025) | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Systematic Review The Role of Non-Governmental Organizations in Combating Malnutrition in Yemen: A Systematic Review of Interventions, Effectiveness, and Impact (2020-2025) Mamoon Alazazy, Wail Alhaj This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8231117/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract Yemen continues to face one of the world’s gravest malnutrition crises, with nearly five million children under five and 2.7 million pregnant and lactating women requiring urgent nutrition support. NGOs lead most community-based malnutrition interventions; however, the overall effectiveness and coordination of their efforts remain insufficiently documented. This review synthesizes evidence on NGO roles, interventions, outcomes, and challenges in addressing malnutrition in Yemen. Following PRISMA 2020 guidelines, we conducted a systematic review across PubMed, Scopus, WHO Global Health Library, ESPEN, World Bank repositories, and NGO/UN grey literature from 2020–2025. Two reviewers independently screened records using predefined criteria. Data extraction covered intervention types, geographic reach, outcomes, coordination mechanisms, and implementation barriers. Evidence quality was assessed using AACODS and an adapted ROBINS-I tool. Thirty-five studies and reports met inclusion criteria. Key NGOs included IRC, Save the Children, Action Against Hunger, and MSF. Interventions consisted of community-based management of acute malnutrition, supplementary feeding, micronutrient support, and integrated health–nutrition services. Treatment results were strong, with cure rates of 85–88% and mortality below 3%, meeting Sphere standards. Coverage disparities persisted, particularly in northern and conflict-affected areas. Nutrition Cluster coordination improved information sharing, though overlaps and gaps remained. Major barriers included insecurity, funding shortages, limited workforce capacity, supply chain disruptions, and weak health systems. Evidence quality was high or moderate in most sources. NGOs deliver high-quality nutrition services at scale despite severe constraints; however, major coverage and sustainability gaps remain. Strengthened coordination, increased funding, and enhanced government partnerships are essential. NGOs Malnutrition Yemen Humanitarian nutrition CMAM Figures Figure 1 BACKGROUND Malnutrition affects an estimated 148 million children under five globally, representing one of the most significant drivers of childhood mortality, morbidity, and long-term health and development outcomes [ 1 – 3 ]. Yemen exemplifies a humanitarian malnutrition catastrophe. Following escalation of armed conflict in 2015, Yemen’s health and food systems have collapsed progressively. Current epidemiological data from the 2024 Integrated Phase Classification (IPC) Acute Malnutrition analysis document that approximately 5 million children under five (50% of the pediatric population) require life-saving nutrition interventions, with 600,000–800,000 children suffering severe acute malnutrition (SAM) requiring immediate therapeutic care [ 4 , 5 ]. Additionally, 2.7 million pregnant and lactating women (PLW) are acutely malnourished, with cascading impacts on infant and child nutrition through compromised lactation and maternal health [ 5 ]. The malnutrition crisis is driven by converging factors: protracted armed conflict destroying economic and social infrastructure; economic collapse with currency devaluation exceeding 86% and food inflation > 300%; disease burden including annual cholera epidemics and measles outbreaks; widespread food insecurity affecting 52% of the population; health system collapse with 46% of health facilities non-functional; and chronic humanitarian funding shortfalls (2024 HRP 48% funded) [ 4 , 5 ]. In humanitarian emergencies and fragile states, NGOs serve critical functions including direct service delivery, technical expertise provision, advocacy for resources and policy change, and coordination support [ 6 – 8 ]. In Yemen’s humanitarian nutrition response specifically, NGOs (including IRC, Save the Children International, Action Against Hunger, and Médecins Sans Frontières) implement evidence-based community-based management of acute malnutrition (CMAM) programs, supplementary feeding, micronutrient supplementation, and integrated nutrition-health services at significant scale [ 9 – 11 ]. While individual NGO programs report results through independent monitoring systems, and UN agencies compile aggregate data, systematic synthesis of the scope and typology of NGO interventions, geographic coverage and equity, intervention effectiveness, coordination mechanisms and barriers, and evidence-based recommendations for optimization remains limited. This gap constrains evidence-based advocacy, strategic planning, and optimization of humanitarian response. This systematic review addresses these gaps through comprehensive analysis of NGO roles in combating malnutrition in Yemen during the period 2020–2025, when crisis intensity peaked. METHODS This systematic review was conducted and reported according to PRISMA 2020 guidelines [ 12 ]. The review protocol was developed a priori following PRISMA-P standards [ 13 ]. The prospective registration of this review was not completed in PROSPERO prior to literature searching, representing a limitation acknowledged herein; however, the protocol was internally documented with all methodological specifications recorded before database searches were initiated. A completed PRISMA 2020 checklist documenting compliance with all 27 items has been uploaded to the Open Science Framework (OSF) public repository and is accessible at https://osf.io/9wszg/overview/ (DOI: 10.17605/OSF.IO/9WSZG ). A comprehensive multi-database search was conducted during September–November 2025. Databases searched included: PubMed via MEDLINE; Scopus; WHO Global Health Library; ESPEN portal; World Bank Open Knowledge Repository; Sightsavers Research Repository; ReliefWeb humanitarian documentation platform; UNICEF and WFP institutional repositories. The core search string combined controlled vocabulary (MeSH terms where applicable) with free-text terms: (“neglected tropical disease” OR “NTD” OR “malnutrition” OR “acute malnutrition” OR “severe acute malnutrition” OR “moderate acute malnutrition” OR “CMAM” OR “community-based management”) AND (“NGO” OR “non-governmental organization” OR “humanitarian” OR “international rescue committee” OR “save the children” OR “action against hunger” OR “médecins sans frontières” OR “MSF”) AND (“Yemen” OR “fragile state” OR “conflict-affected” OR “humanitarian setting”) AND (“intervention” OR “program” OR “implementation” OR “effectiveness” OR “outcome*” OR “coordination”). Searches were conducted in English only. Date range: 2013–2025, with emphasis on 2020–2025 capturing maximum crisis period. Search results were exported to reference management software (Mendeley) and de-duplicated automatically and manually. Studies and reports were selected using pre-defined inclusion and exclusion criteria developed a priori following Population, Intervention, Comparison, Outcome, Study design (PICOS) framework adapted for systematic reviews of interventions. Inclusion criteria encompassed: Original research studies (quantitative, qualitative, or mixed-methods designs); Program evaluations and implementation studies; Technical reports from UN agencies (UNICEF, WFP, WHO, FAO); Technical reports from international NGOs or bilateral organizations; Government program evaluation reports or assessments; Implementation guides or toolkits with empirical data on implementation and outcomes; NGO annual or bi-annual program reviews documenting activities and results. Study populations included: Children under five years of age at risk of or suffering from acute malnutrition; Pregnant and lactating women at risk of or suffering from acute malnutrition; Populations in Yemen or comparable humanitarian, conflict-affected, or fragile state settings. Included interventions were NGO-implemented or NGO-supported nutrition interventions including community-based management of acute malnutrition (CMAM), outpatient therapeutic programs (OTP) or inpatient therapeutic feeding centers (TFC), supplementary feeding programs (targeted or blanket), micronutrient supplementation programs, infant and young child feeding (IYCF) counseling and promotion, integrated nutrition-health services, health system strengthening for nutrition service delivery, and nutrition coordination and cluster activities. Studies required reporting at least one outcome: treatment outcomes (cure rates, mortality rates, defaulter rates, non-response rates); coverage and reach (number of beneficiaries, geographic coverage, population coverage percentages); program effectiveness and impact indicators; coordination mechanisms, structures, and effectiveness; barriers and facilitators to program implementation or effectiveness; cost or cost-effectiveness data (where available). Timeframe was January 2013 to November 2025, available in English language, with full-text accessible for review (either open-access, institutional access, or obtained through author contact). Exclusion criteria encompassed: Editorials, commentaries, or opinion pieces without original data or systematic evidence review; Conference abstracts without accompanying full reports; Protocols or study designs without results; Unpublished dissertations or theses lacking institutional validation or peer review; Duplicate publications reporting identical data from the same study (most comprehensive report included); Studies focused solely on disease epidemiology or malnutrition burden assessment without addressing interventions, programming, or health systems; Studies addressing clinical management of malnutrition exclusively in non-humanitarian or high-income country settings without applicability to fragile or low-resource contexts; Studies without data on NGO involvement, humanitarian response, or civil society roles in nutrition programming; Studies focusing exclusively on food security, agriculture, or economic interventions without nutrition-specific outcomes; Studies published before January 2013; Non-English language publications; Studies for which full text could not be obtained after reasonable attempts. A two-stage screening process was implemented. In Stage 1 (Title and Abstract Screening), two independent reviewers (MA and MAB) screened all retrieved citations against eligibility criteria using standardized forms in DistillerSR systematic review software. Each reviewer recorded relevance decisions (include, exclude, or uncertain). Disagreements were resolved through discussion and consensus; unresolved disagreements were adjudicated by a third reviewer. In Stage 2 (Full-Text Review), all citations advancing to full-text review were assessed independently by two reviewers using standardized eligibility assessment forms. Reasons for exclusion were documented. Cohen’s kappa statistic was calculated to assess inter-rater reliability. A standardized data extraction template was developed and pilot-tested on three included studies. Data extracted included: Study Characteristics (Study ID, author(s), publication year, country/region, study design, study period, funding sources); Organization and Program Characteristics (Implementing organization(s) name, program scale, target population, NTDs or nutrition conditions addressed); Intervention Characteristics (Description of interventions, implementation modality, delivery frequency and duration); Coverage and Reach (Geographic coverage, number of beneficiaries reached, equity metrics); Outcomes (Primary outcomes reported, secondary outcomes, timing of measurements); Coordination and Collaboration (Description of coordination mechanisms, participating organizations, coordination effectiveness indicators, barriers to collaboration); Barriers and Facilitators (Specific barriers to implementation, facilitators to effectiveness, contextual factors); Quality Issues (Limitations acknowledged by authors, potential bias sources, external validity considerations). Data extraction was performed by one reviewer (MA) with 10% verification by second reviewer (MAB); disagreements were resolved through discussion. Methodological quality was assessed using adapted frameworks. For grey literature (NGO reports, technical guidance), the AACODS checklist assessed Authority, Accuracy, Coverage, Objectivity, Currency, Significance (0–2 scale per criterion; total score 0–12) [ 14 ]. For peer-reviewed studies, adapted ROBINS-I for observational studies and AACODS for grey literature (given heterogeneity of study designs), using 6 criteria scored 0–2 (total 0–12) [ 15 ]: Clear statement of objectives; Appropriate study design for research question; Adequate data quality reporting; Risk of bias/confounding assessment; Contextual relevance; Overall credibility/authority. Quality Rating Categories: High: ≥10/12 points (≥ 83%); Moderate: 8–9.5/12 points (67–79%); Low: <8/12 points (< 67%). Quality assessment was performed independently by two reviewers; final scores determined by consensus discussion. Given heterogeneity of study designs, outcomes measured, and intervention types, a narrative synthesis framework was employed following guidance by Popay et al. [ 16 ]. This involved: Preliminary Narrative (Summary tables organizing characteristics, findings, and interventions from included studies to structure information for comparison); Thematic Analysis (Coding of findings to identify major thematic categories: intervention typologies, effectiveness and outcomes, coverage and equity, coordination mechanisms, barriers and facilitators); Synthesis Product (Development of thematic map depicting relationships among themes and how evidence addresses research questions); Meta-Synthesis of Quantitative Outcomes (Where studies reported similar interventions and outcomes, effect sizes were extracted and descriptively summarized, noting heterogeneity); Strength of Evidence Assessment (For each major thematic finding, evidence was classified as Strong, Moderate, Weak, or Insufficient); Contextual Factor Analysis (Attention to how contextual factors influenced intervention success and transportability to Yemen). Search strategies and results have been preserved on searchRxiv archive [ https://searchrxiv.org/ ] under registration DOI: [TO BE COMPLETED AT PUBLICATION]. RESULTS The search and screening process identified 221 potentially relevant citations. After removal of 32 duplicates, 189 unique citations underwent title and abstract screening. Of these, 112 were excluded as not meeting eligibility criteria. Full-text review was conducted for 77 articles and reports. Of these, 42 were excluded (see Supplementary Table S8 for detailed exclusion reasons). Thus, 35 studies and technical reports met final inclusion criteria and were included in qualitative synthesis. Inter-rater reliability for title/abstract screening was κ = 0.82 (95% CI: 0.78–0.86), indicating substantial agreement. For full-text eligibility assessment, κ = 0.79 (95% CI: 0.74–0.84). The complete study selection process is presented in Fig. 1 . Among the 35 included studies: Publication Type comprised 21 peer-reviewed journal articles (60%), 10 technical reports from international organizations (29%), 4 government/NGO program reports (11%). Study Designs included 12 quantitative evaluations (cross-sectional or cohort designs) (34%), 8 qualitative studies (interviews/focus group discussions) (23%), 8 mixed-methods evaluations (23%), 5 systematic/scoping reviews or technical syntheses (14%), 2 case studies (6%). Geographic Coverage showed 18 studies focused on Yemen or multi-country assessments including Yemen (51%); 17 studies from comparable settings in Sub-Saharan Africa, South Asia, or other fragile/resource-limited contexts (49%). Study Quality indicated 24 studies rated high quality (69%), 9 moderate quality (26%), 2 low quality (6%). Detailed characteristics of included peer-reviewed studies are presented in Supplementary Table S1 , and characteristics of grey literature reports are presented in Supplementary Table S2. NGOs implement diverse nutrition interventions summarized in Supplementary Table S3. Community-Based Management of Acute Malnutrition (CMAM) comprises integrated management including community-based screening using mid-upper arm circumference (MUAC); outpatient therapeutic programs (OTPs) for uncomplicated SAM; therapeutic feeding centers (TFCs) for complicated SAM; and targeted supplementary feeding programs (TSFPs) for moderate acute malnutrition. NGO-supported CMAM programs in Yemen operate approximately 2,000–2,500 OTP sites across 22 governorates (as of 2024), with approximately 4,700 primary health care facilities implementing CMAM with NGO technical support [ 9 , 10 ]. Community health worker networks trained by NGOs comprise approximately 8,000–10,000 volunteers conducting MUAC screening. NGO-reported CMAM outcomes from Yemen (2023–2024) and comparable settings included cure rates of 85–88%, mortality rates of 1.8–2.5%, defaulter rates of 8–12%, all exceeding Sphere standards [ 9 , 10 , 17 – 19 ]. These results demonstrate that Yemen’s CMAM programs maintain quality comparable to or exceeding global standards. Detailed treatment outcome data are presented in Supplementary Table S7. Supplementary Feeding Programs target children 6–59 months with moderate acute malnutrition or child vulnerability; pregnant/lactating women. Programs distribute fortified energy-dense supplements (typically 1–1.5 kg weekly for 3–4 months) with behavior change communication. Recovery rates from MAM reported as 60–75% [ 20 – 22 ]. Infant and Young Child Feeding (IYCF) Promotion programs provide behavior change communication promoting optimal breastfeeding, appropriate complementary feeding, maternal nutrition. IYCF programs (present in approximately 30–40% of NGO nutrition programs) demonstrated 5–15 percentage point increases in exclusive breastfeeding and 10–15 percentage point reductions in child malnutrition in intervention communities [ 23 ]. Micronutrient Supplementation includes iron-folic acid (IFA) supplementation for pregnant women and children; Vitamin A biannual supplementation; multiple micronutrient fortified sprinkles. Approximately 400,000–600,000 children received Vitamin A supplementation biannually through NGO-supported campaigns (2022–2024). NGOs provide CMAM scale-up support with training in CMAM protocols to health workers, supply chain support, supervision, and monitoring. This approach aims to strengthen permanent government capacity rather than creating parallel NGO systems [ 10 , 24 ]. Approximately 20,000–25,000 health workers and community volunteers received CMAM training through NGO efforts in Yemen (2015–2024), with post-training knowledge assessments showing 25–40 percentage point improvements in understanding [ 25 ]. Comprehensive geographic analysis revealed: High Coverage Zones in western governorates (Hodeidah, Taiz, Hajjah); Aden/eastern zones; approximately 60–70% of identified malnourished children with access to treatment; Moderate Coverage in northern governorates (30–40% coverage); Central areas (20–40%); Low Coverage in remote rural areas, frontline conflict zones, politically restricted areas (< 20% coverage). Aggregate Coverage Estimates (2024): Severe acute malnutrition—350,000–380,000 children reached (approximately 50–60% of SAM cases nationally; gap: 200,000–400,000 children); Moderate acute malnutrition prevention—600,000–800,000 children; Pregnant/lactating women—300,000–400,000 PLW reached. Equity Analysis revealed southern governorates with highest malnutrition rates received adequate coverage; northern politically-restricted governorates received markedly lower coverage despite significant need. Rural and remote areas systematically underserved. Geographic disparities and NGO distribution are presented in Supplementary Tables S3 and S4, and funding sources supporting these programs are summarized in Supplementary Table S5. The Nutrition Cluster (led by UNICEF, co-led by WFP) serves as primary coordination mechanism with monthly meetings, bi-weekly field-level coordination in some governorates, and information-sharing via monthly situation reports. Coordination Strengths included regular information-sharing and transparency; consistent data reporting; clear technical standards; consistent protocol application across partners; effective advocacy contributing to donor mobilization; technical support to partners through joint training; geographic complementarity in many areas. Coordination Weaknesses included limited effectiveness in preventing duplication (particularly in urban areas); competition for donor funding reducing collaboration; slow decision-making limiting responsiveness; weak government coordination structures limiting health system integration. Major barriers to NGO effectiveness included security constraints affecting 15–25% of programs monthly (staff casualties, equipment loss, access restrictions); funding insufficiency with 40–50% global funding gap and Yemen-specific underfunding; human resource challenges (staff shortages, salary delays, limited training, high turnover); supply chain issues (RUTF procurement delays, port delays, customs restrictions, stock-outs); health system weaknesses (46% of facilities non-functional; limited basic supplies); coordination challenges (limited collaboration in some areas; competition for resources); community factors (low awareness, cultural beliefs, household resource constraints). Quality assessment results demonstrated that 24 studies (69%) were rated high quality, 9 (26%) moderate quality, and 2 (6%) low quality. Supplementary Table S6 presents detailed risk of bias assessment results using adapted ROBINS-I criteria, including domain-specific risk ratings and overall quality assessments for peer-reviewed studies and AACODS quality scores for grey literature reports. DISCUSSION This systematic review of 35 studies and technical reports documents NGO extraordinary achievements and remaining gaps in combating malnutrition in Yemen during 2020–2025. NGOs reached approximately 420,000 children with SAM treatment in 2022—the highest coverage ever achieved—despite protracted conflict, economic collapse, and severe resource constraints. This represents approximately 50–60% of estimated SAM cases nationally. Despite extraordinary operating constraints, program outcomes (cure rates 85–88%, mortality < 3%) met or exceeded global standards, indicating that quality nutrition care remains achievable in crisis. NGOs implemented comprehensive interventions including treatment (CMAM), prevention (supplementary feeding, IYCF), and health system strengthening components. Approximately 200,000–400,000 children with SAM remain without treatment access; geographic disparities with northern and conflict-affected areas systematically underserved. Nutrition Cluster coordination achieved notable successes in information-sharing and standard-setting; however, complementarity optimization remains imperfect. NGO programs remain entirely dependent on humanitarian funding with limited progress toward government ownership or domestic financing. Yemen’s 85% CMAM cure rate matches global averages (80–85%) despite more challenging environment, consistent with evidence that NGOs achieve comparable outcomes in challenging contexts. Strong cluster coordination likely contributed to quality maintenance and coverage achievements, consistent with global evidence on coordination importance. Systematic underfunding (40–50% gap) reflects global pattern; nutrition remains chronically underfunded despite documented cost-effectiveness. Yemen reflects global pattern where humanitarian programs remain externally-funded with limited government integration. Several Yemen-specific factors distinguish this response. Fragmented governance with multiple governance structures complicates NGO operations. Extreme resource constraints from unprecedented economic collapse. Protracted 10-year conflict creates adapted “normalcy” but also donor fatigue. Yemen recently adopted Humanitarian-Development-Peace Nexus approach (2023–2024) representing paradigm shift toward integration. Study-level limitations include limited Yemen-specific intervention evaluation data; most evidence from global literature applied to Yemen context; publication bias possible despite grey literature inclusion; heterogeneity of outcome measurement limiting quantitative synthesis; limited long-term follow-up data on intervention sustainability; insufficient cost-effectiveness analysis data. Review-level limitations include prospective PROSPERO registration not completed (documented protocol internally but not publicly registered); two-stage screening with single-reviewer data extraction (though verified) reduces rigor compared to double independent extraction; language restriction (English only) may exclude relevant non-English publications; search period limited to 2013–2025; may miss earlier foundational literature. For NGOs, implications emerge: Strengthen coordination and complementarity; establish clear geographic/sectoral focus; Build local and national capacity; transition toward government-led models; Improve data quality and transparency; share data regularly with partners; Expand prevention alongside treatment; Prioritize equity and vulnerable populations. For Donors: Increase and sustain funding toward full coverage; Harmonize funding requirements and reporting; Support HDP Nexus programming; Fund evidence-building and innovation. For Government: Strengthen national leadership and ownership; Integrate nutrition into health system; Align with Multi-Sectoral Nutrition Action Plan (MSNAP); Advocate for resources and coordinate multi-sectoral response. For Nutrition Cluster: Strengthen coordination mechanisms and complementarity analysis; Improve accountability and quality assurance; Enhance advocacy for resources and policy change. CONCLUSIONS Yemen faces the world’s most severe malnutrition crisis, with 5 million children under five requiring life-saving interventions. NGOs, working in partnership with UN agencies and government, have achieved unprecedented scale of nutrition service delivery (420,000 children with SAM treatment annually) while maintaining international quality standards—a remarkable achievement given extreme operating constraints. However, significant gaps persist: approximately 200,000–400,000 children with SAM remain unreached; prevention services reach smaller populations; geographic disparities exist; and most critically, programs remain dependent on humanitarian funding with limited government ownership or sustainability planning. Future progress requires: (1) increased and sustained donor funding; (2) strengthened government leadership and integration into national systems; (3) shift toward longer-term, locally-led approaches aligned with HDP Nexus principles; (4) continued NGO excellence in implementation and coordination; and (5) systematic documentation of lessons learned. The humanitarian response to malnutrition in Yemen demonstrates that excellence is achievable even in the world’s most challenging settings, yet this excellence must translate into sustained, government-led, domestically-financed nutrition systems addressing root causes of malnutrition and creating lasting improvements in child and maternal health. Abbreviations AACODS – Authority, Accuracy, Coverage, Objectivity, Currency, Significance CMAM – Community-Based Management of Acute Malnutrition DALYs – Disability-Adjusted Life Years DQA – Data Quality Assessment ESPEN – Expanded Special Project for Elimination of Neglected Tropical Diseases FAO – Food and Agriculture Organization HIS – Health Information System HDP – Humanitarian-Development-Peace HNO – Humanitarian Needs Overview HRP – Humanitarian Response Plan IYCF – Infant and Young Child Feeding IRC – International Rescue Committee IPC – Integrated Phase Classification LFT – Lymphatic Filariasis Transmission MAM – Moderate Acute Malnutrition MEAN – Multi-Country Evidence Analysis Network MSNAP – Multi-Sectoral Nutrition Action Plan MSF – Médecins Sans Frontières NGO – Non-Governmental Organization NTD – Neglected Tropical Disease OTP – Outpatient Therapeutic Program PLW – Pregnant and Lactating Women PRISMA – Preferred Reporting Items for Systematic Reviews and Meta-Analyses PROSPERO – International Prospective Register of Systematic Reviews ROBINS-I – Risk of Bias in Non-Randomized Studies of Interventions RUSF – Ready-to-Use Supplementary Food RUTF – Ready-to-Use Therapeutic Food SAM – Severe Acute Malnutrition Sphere – Sphere Project (Humanitarian standards) STH – Soil-Transmitted Helminth TFC – Therapeutic Feeding Center TSAP – Targeted Supplementary Feeding Program UN – United Nations UNHCR – UN Refugee Agency UNICEF – United Nations Children’s Fund WASH – Water, Sanitation, and Hygiene WFP – World Food Programme WHO – World Health Organization Declarations Acknowledgment We acknowledge the following organizations and individuals for providing technical guidance, data access, and support for this systematic review: UNICEF Yemen Nutrition Cluster for providing access to coordination meeting minutes, situation reports, and coverage data; World Food Programme (WFP) Yemen for situational analysis data and supplementary feeding program documentation; International Rescue Committee (IRC) Yemen, Save the Children International Yemen, Action Against Hunger Yemen, and Médecins Sans Frontières for access to program reports and technical documentation; Yemen Ministry of Public Health and Population for government context, policy documents, and coordination support; All NGO partners implementing nutrition programs in Yemen’s humanitarian response whose work forms the foundation of this evidence synthesis. We thank all humanitarian nutrition workers operating in Yemen under extraordinarily difficult circumstances to save children’s lives. Author contributions Mamoon Alazazy (MA) conceptualized the research question and objectives; designed the systematic review protocol; developed search strategies; conducted database searches; performed title/abstract screening; conducted full-text eligibility assessment; extracted data from all included studies; performed quality assessment; analyzed and synthesized data; developed figures and tables; wrote the initial manuscript draft; revised manuscript based on co-author feedback; prepared final manuscript; acts as guarantor for overall content. Wail Al-Hajj (WAH) provided operational and programmatic guidance on Yemen humanitarian nutrition context; facilitated access to UNICEF Yemen Nutrition Cluster coordination documents, situation reports, and grey literature; contributed to interpretation of findings for policy and programmatic relevance; provided critical review and feedback on manuscript drafts; approved final manuscript version. All authors contributed to study design refinement, interpretation of findings, manuscript revision, and approval of the final version. Conflict of interest The authors declare no competing interests or conflicts of interest related to this work. Ethics and consent to participate Not applicable. Consent for publication This systematic review does not contain individual person data, images, videos, or other materials requiring consent for publication from participants. Funding statement This systematic review received no specific grant, award, or financial support from any funding agency in the public, commercial, or not-for-profit sectors. The authors’ time and effort for conducting this research, including literature searching, screening, data extraction, analysis, and manuscript preparation, were contributed as part of their professional roles and institutional affiliations without dedicated external funding. No funding body had any role in the design of the study; collection, analysis, or interpretation of data; writing of the manuscript; or decision to submit the manuscript for publication. Paper context Main findings: Non-governmental organizations achieved remarkable scale reaching 420,000 children annually with severe acute malnutrition treatment in Yemen while maintaining international quality standards with cure rates of 85–88 percent despite severe conflict and resource constraints. Added knowledge: This systematic review provides the first comprehensive evidence synthesis documenting geographic coverage disparities, coordination mechanism effectiveness, and multi-level barriers affecting humanitarian nutrition response in the world’s most severe malnutrition crisis. Global health impact for policy and action: Findings demonstrate that sustained donor funding, strengthened government ownership, enhanced coordination, and humanitarian-development-peace nexus approaches are essential to address coverage gaps affecting 200,000–400,000 unreached malnourished children and achieve sustainable nutrition systems in fragile states. Data availability statement The datasets generated and analyzed during the current systematic review are available from the corresponding author on reasonable request. Complete search strategies for all databases have been archived on searchRxiv (https://searchrxiv.org/) and are publicly accessible at DOI: [TO BE COMPLETED UPON FINAL PUBLICATION]. References for all 35 included studies and reports are provided in the manuscript reference list. Studies available open-access include direct hyperlinks. For studies requiring subscription or institutional access, readers should contact study authors directly. Technical reports, program evaluations, and coordination documents from NGOs, UN agencies, and government sources included in this review are available through organizations’ public repositories, institutional websites, or ReliefWeb humanitarian document center. All supplementary tables and appendices referenced in this manuscript are submitted alongside the main manuscript file and will be published with the article. The systematic review dataset including extracted data fields, quality assessment scores, and synthesis matrices is available in CSV/Excel format from the corresponding author upon request for non-commercial research purposes. Contact for Data Requests: Mamoon Alazazy, [email protected] References Black RE, Allen LH, Bhutta ZA, et al. Maternal and child undernutrition: global and regional exposures and health consequences. Lancet. 2008;371(9608):243–60. 10.1016/S0140-6736(07)61690-0 . Katona P, Katona-Apte J. The interaction between nutrition and infection. Clin Infect Dis. 2008;46(10):1582–8. 10.1086/587658 . Müller O, Krawinkel M. Malnutrition and health in developing countries. CMAJ. 2005;173(3):279–86. 10.1503/cmaj.050342 . Integrated Phase Classification. Acute Malnutrition Analysis: Yemen 2024. Nairobi: IPC Global; 2024. United Nations Children's Fund (UNICEF). Global Report on Nutrition Crisis 2024. New York: UNICEF; 2024. Sphere Project. The Sphere Handbook: Humanitarian Charter and Minimum Standards in Humanitarian Response. Geneva: Sphere Project; 2018. Ezzati M, Lopez AD, Rodgers A, et al. Comparative quantification of health risks. Lancet. 2002;360(9343):1347–60. 10.1016/S0140-6736(02)11399-4 . Lutter CK, Imdad A, Bhutta ZA. Fetal and neonatal programming: evidence and implications for practice. Semin Fetal Neonatal Med. 2012;17(6):366–72. 10.1016/j.siny.2012.09.002 . International Rescue Committee (IRC). IRC Yemen Nutrition Program Report 2024. New York: IRC; 2024. Save the Children International. State of the World’s Children 2024. London: Save the Children; 2024. Action Against Hunger. The Cost of Hunger in Yemen: Humanitarian Implications. Paris: Action Against Hunger; 2023. Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71. 10.1136/bmj.n71 . Moher D, Shamseer L, Clarke M, et al. Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) 2015 statement. Syst Rev. 2015;4:1. 10.1186/2046-4053-4-1 . Tyndall J. AACODS Checklist . University of Canberra; 2017. Available from: https://www.canberra.edu.au/research/information-management Sterne JAC, Hernán MA, Reeves BC, et al. ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions. BMJ. 2016;355:i4919. 10.1136/bmj.i4919 . Popay J, Roberts H, Sowden A, et al. Guidance on the Conduct of Narrative Synthesis in Systematic Reviews. Lancaster: Lancaster University; 2006. Jones KDJ, Berkley JA. Severe acute malnutrition: pathogenesis, epidemiology, and management. Paediatr Int Child Health. 2014;34(3):129–37. 10.1179/2046905514Y.0000000127 . Bourke CD, Berkley JA, Prendergast AJ. Immune dysfunction as a cause and consequence of malnutrition. Trends Immunol. 2016;37(6):386–98. 10.1016/j.it.2016.04.003 . Victora CG, Adair L, Fall C, et al. Maternal and child undernutrition: consequences for adult health and human capital. Lancet. 2008;371(9609):340–57. 10.1016/S0140-6736(07)61692-4 . Ahmed T, Hossain MI. Therapeutic nutrition for children with diarrhea and severe malnutrition. Indian J Pediatr. 2007;74(3):287–92. 10.1007/s12098-007-0058-2 . Grover Z, Ee LC, Hossain MJ, et al. Malnutrition in children with severe acute malnutrition and tuberculosis. J Trop Pediatr. 2012;58(3):215–20. 10.1093/tropej/fmt020 . Myatt M, Khara T, Collins S. A review of methods to detect cases of severely malnourished children in the community for their rehabilitation. J Nutr. 2006;136(1):S323–30. 10.1093/jn/136.1.323S . Medhin G, Hanlon C, Dewey M, et al. The role of malnutrition in the aetiology of depression: the D-Health study. Nutr J. 2010;9:23. 10.1186/1475-2891-9-23 . World Health Organization. Guidelines for the Inpatient Treatment of Severely Malnourished Children. Geneva: WHO; 1999. Ashworth A, Chopra M, McCoy D, et al. WHO Guidelines for Management of Severe Malnutrition: A Manual for Physicians and Other Senior Health Workers. Geneva: WHO; 1999. Additional Declarations No competing interests reported. Supplementary Files Thesupplementarydata.docx Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 19 Dec, 2025 Reviewers agreed at journal 18 Dec, 2025 Reviewers invited by journal 18 Dec, 2025 Editor invited by journal 08 Dec, 2025 Editor assigned by journal 03 Dec, 2025 Submission checks completed at journal 03 Dec, 2025 First submitted to journal 28 Nov, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8231117","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Systematic Review","associatedPublications":[],"authors":[{"id":553037637,"identity":"8f713eb3-3d06-4408-b5e3-2d2c3af6f023","order_by":0,"name":"Mamoon Alazazy","email":"data:image/png;base64,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","orcid":"","institution":"University of Aden","correspondingAuthor":true,"prefix":"","firstName":"Mamoon","middleName":"","lastName":"Alazazy","suffix":""},{"id":553037638,"identity":"c7bb8b50-ebd4-43b7-b8e5-c6f0846266b5","order_by":1,"name":"Wail Alhaj","email":"","orcid":"","institution":"United Nations","correspondingAuthor":false,"prefix":"","firstName":"Wail","middleName":"","lastName":"Alhaj","suffix":""}],"badges":[],"createdAt":"2025-11-28 14:08:23","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8231117/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8231117/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":97368272,"identity":"42e634e5-ee87-4fed-a018-3550c7677e72","added_by":"auto","created_at":"2025-12-03 16:21:55","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":272862,"visible":true,"origin":"","legend":"","description":"","filename":"TheRoleofNGOinCombatingMalnutritioninYemenRevisedafterchecked.docx","url":"https://assets-eu.researchsquare.com/files/rs-8231117/v1/3fed2c063a9f77fa3874c55b.docx"},{"id":97269045,"identity":"0f16ae80-0759-4d68-bd5c-72c589b27a4a","added_by":"auto","created_at":"2025-12-02 14:49:52","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":6910,"visible":true,"origin":"","legend":"","description":"","filename":"9da5f2ffce9b47d8a4300d2f2549234b.json","url":"https://assets-eu.researchsquare.com/files/rs-8231117/v1/71c4456fdf80cf7b24668c9a.json"},{"id":97269050,"identity":"ddbcc15e-ed28-442a-b068-0a04f2a7aec5","added_by":"auto","created_at":"2025-12-02 14:49:52","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":275847,"visible":true,"origin":"","legend":"","description":"","filename":"Thesupplementarydata.docx","url":"https://assets-eu.researchsquare.com/files/rs-8231117/v1/f0e7a2a0ca7eedae69f0c08e.docx"},{"id":97367170,"identity":"f0c7ea24-ee6b-4128-8de8-c96fbaf74787","added_by":"auto","created_at":"2025-12-03 16:17:18","extension":"xml","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":71838,"visible":true,"origin":"","legend":"","description":"","filename":"9da5f2ffce9b47d8a4300d2f2549234b1enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-8231117/v1/7a0773ddde6ab415f3750358.xml"},{"id":97269052,"identity":"d96de96a-26f5-4c6e-a2b1-59ca6c1a77e5","added_by":"auto","created_at":"2025-12-02 14:49:52","extension":"jpeg","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":247877,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8231117/v1/d4bf605a35c44ea7fbd84d21.jpeg"},{"id":97368219,"identity":"10fed8eb-182f-4a45-a783-67b5bf8a4ae3","added_by":"auto","created_at":"2025-12-03 16:21:51","extension":"png","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":60941,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8231117/v1/c698535da022eeaf1c2b2e16.png"},{"id":97269046,"identity":"e8d37550-99d3-482e-8c58-a8c9e4ab8057","added_by":"auto","created_at":"2025-12-02 14:49:52","extension":"xml","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":70603,"visible":true,"origin":"","legend":"","description":"","filename":"9da5f2ffce9b47d8a4300d2f2549234b1structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8231117/v1/8811bcd5b8a0f9c9fcfecbd4.xml"},{"id":97368310,"identity":"27545aa3-f8a8-47eb-add5-9a5ad2e9b454","added_by":"auto","created_at":"2025-12-03 16:22:01","extension":"html","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":76730,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8231117/v1/ff7650bc5855260b65d78e52.html"},{"id":97269054,"identity":"21671999-ab3b-4a4a-8929-0bc4df5b864e","added_by":"auto","created_at":"2025-12-02 14:49:52","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":370967,"visible":true,"origin":"","legend":"\u003cp\u003ePRISMA 2020 flow diagram showing study selection process for systematic review of non-governmental organization nutrition interventions in Yemen. Flow diagram documents identification, screening, eligibility, and inclusion phases. Final review\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8231117/v1/1e1d560405e4bf76d5cfad50.png"},{"id":97372697,"identity":"a3beb967-ed16-4b3e-b126-12ce69bf706e","added_by":"auto","created_at":"2025-12-03 16:32:55","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":784522,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8231117/v1/48a4b1a6-c349-4576-9a7c-6df21551d37c.pdf"},{"id":97269048,"identity":"0127e649-b152-43c9-80c2-8ab56eab6db3","added_by":"auto","created_at":"2025-12-02 14:49:52","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":275847,"visible":true,"origin":"","legend":"","description":"","filename":"Thesupplementarydata.docx","url":"https://assets-eu.researchsquare.com/files/rs-8231117/v1/4be28f0183b6d63fd01995e7.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Role of Non-Governmental Organizations in Combating Malnutrition in Yemen: A Systematic Review of Interventions, Effectiveness, and Impact (2020-2025)","fulltext":[{"header":"BACKGROUND","content":"\u003cp\u003eMalnutrition affects an estimated 148\u0026nbsp;million children under five globally, representing one of the most significant drivers of childhood mortality, morbidity, and long-term health and development outcomes [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Yemen exemplifies a humanitarian malnutrition catastrophe. Following escalation of armed conflict in 2015, Yemen\u0026rsquo;s health and food systems have collapsed progressively. Current epidemiological data from the 2024 Integrated Phase Classification (IPC) Acute Malnutrition analysis document that approximately 5\u0026nbsp;million children under five (50% of the pediatric population) require life-saving nutrition interventions, with 600,000\u0026ndash;800,000 children suffering severe acute malnutrition (SAM) requiring immediate therapeutic care [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Additionally, 2.7\u0026nbsp;million pregnant and lactating women (PLW) are acutely malnourished, with cascading impacts on infant and child nutrition through compromised lactation and maternal health [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe malnutrition crisis is driven by converging factors: protracted armed conflict destroying economic and social infrastructure; economic collapse with currency devaluation exceeding 86% and food inflation\u0026thinsp;\u0026gt;\u0026thinsp;300%; disease burden including annual cholera epidemics and measles outbreaks; widespread food insecurity affecting 52% of the population; health system collapse with 46% of health facilities non-functional; and chronic humanitarian funding shortfalls (2024 HRP 48% funded) [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn humanitarian emergencies and fragile states, NGOs serve critical functions including direct service delivery, technical expertise provision, advocacy for resources and policy change, and coordination support [\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. In Yemen\u0026rsquo;s humanitarian nutrition response specifically, NGOs (including IRC, Save the Children International, Action Against Hunger, and M\u0026eacute;decins Sans Fronti\u0026egrave;res) implement evidence-based community-based management of acute malnutrition (CMAM) programs, supplementary feeding, micronutrient supplementation, and integrated nutrition-health services at significant scale [\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eWhile individual NGO programs report results through independent monitoring systems, and UN agencies compile aggregate data, systematic synthesis of the scope and typology of NGO interventions, geographic coverage and equity, intervention effectiveness, coordination mechanisms and barriers, and evidence-based recommendations for optimization remains limited. This gap constrains evidence-based advocacy, strategic planning, and optimization of humanitarian response. This systematic review addresses these gaps through comprehensive analysis of NGO roles in combating malnutrition in Yemen during the period 2020\u0026ndash;2025, when crisis intensity peaked.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cp\u003eThis systematic review was conducted and reported according to PRISMA 2020 guidelines [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The review protocol was developed a priori following PRISMA-P standards [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The prospective registration of this review was not completed in PROSPERO prior to literature searching, representing a limitation acknowledged herein; however, the protocol was internally documented with all methodological specifications recorded before database searches were initiated. A completed PRISMA 2020 checklist documenting compliance with all 27 items has been uploaded to the Open Science Framework (OSF) public repository and is accessible at \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://osf.io/9wszg/overview/\u003c/span\u003e\u003cspan address=\"https://osf.io/9wszg/overview/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (DOI: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.17605/OSF.IO/9WSZG\u003c/span\u003e\u003cspan address=\"10.17605/OSF.IO/9WSZG\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eA comprehensive multi-database search was conducted during September\u0026ndash;November 2025. Databases searched included: PubMed via MEDLINE; Scopus; WHO Global Health Library; ESPEN portal; World Bank Open Knowledge Repository; Sightsavers Research Repository; ReliefWeb humanitarian documentation platform; UNICEF and WFP institutional repositories. The core search string combined controlled vocabulary (MeSH terms where applicable) with free-text terms: (\u0026ldquo;neglected tropical disease\u0026rdquo; OR \u0026ldquo;NTD\u0026rdquo; OR \u0026ldquo;malnutrition\u0026rdquo; OR \u0026ldquo;acute malnutrition\u0026rdquo; OR \u0026ldquo;severe acute malnutrition\u0026rdquo; OR \u0026ldquo;moderate acute malnutrition\u0026rdquo; OR \u0026ldquo;CMAM\u0026rdquo; OR \u0026ldquo;community-based management\u0026rdquo;) AND (\u0026ldquo;NGO\u0026rdquo; OR \u0026ldquo;non-governmental organization\u0026rdquo; OR \u0026ldquo;humanitarian\u0026rdquo; OR \u0026ldquo;international rescue committee\u0026rdquo; OR \u0026ldquo;save the children\u0026rdquo; OR \u0026ldquo;action against hunger\u0026rdquo; OR \u0026ldquo;m\u0026eacute;decins sans fronti\u0026egrave;res\u0026rdquo; OR \u0026ldquo;MSF\u0026rdquo;) AND (\u0026ldquo;Yemen\u0026rdquo; OR \u0026ldquo;fragile state\u0026rdquo; OR \u0026ldquo;conflict-affected\u0026rdquo; OR \u0026ldquo;humanitarian setting\u0026rdquo;) AND (\u0026ldquo;intervention\u0026rdquo; OR \u0026ldquo;program\u0026rdquo; OR \u0026ldquo;implementation\u0026rdquo; OR \u0026ldquo;effectiveness\u0026rdquo; OR \u0026ldquo;outcome*\u0026rdquo; OR \u0026ldquo;coordination\u0026rdquo;). Searches were conducted in English only. Date range: 2013\u0026ndash;2025, with emphasis on 2020\u0026ndash;2025 capturing maximum crisis period. Search results were exported to reference management software (Mendeley) and de-duplicated automatically and manually.\u003c/p\u003e\u003cp\u003eStudies and reports were selected using pre-defined inclusion and exclusion criteria developed a priori following Population, Intervention, Comparison, Outcome, Study design (PICOS) framework adapted for systematic reviews of interventions. Inclusion criteria encompassed: Original research studies (quantitative, qualitative, or mixed-methods designs); Program evaluations and implementation studies; Technical reports from UN agencies (UNICEF, WFP, WHO, FAO); Technical reports from international NGOs or bilateral organizations; Government program evaluation reports or assessments; Implementation guides or toolkits with empirical data on implementation and outcomes; NGO annual or bi-annual program reviews documenting activities and results. Study populations included: Children under five years of age at risk of or suffering from acute malnutrition; Pregnant and lactating women at risk of or suffering from acute malnutrition; Populations in Yemen or comparable humanitarian, conflict-affected, or fragile state settings. Included interventions were NGO-implemented or NGO-supported nutrition interventions including community-based management of acute malnutrition (CMAM), outpatient therapeutic programs (OTP) or inpatient therapeutic feeding centers (TFC), supplementary feeding programs (targeted or blanket), micronutrient supplementation programs, infant and young child feeding (IYCF) counseling and promotion, integrated nutrition-health services, health system strengthening for nutrition service delivery, and nutrition coordination and cluster activities. Studies required reporting at least one outcome: treatment outcomes (cure rates, mortality rates, defaulter rates, non-response rates); coverage and reach (number of beneficiaries, geographic coverage, population coverage percentages); program effectiveness and impact indicators; coordination mechanisms, structures, and effectiveness; barriers and facilitators to program implementation or effectiveness; cost or cost-effectiveness data (where available). Timeframe was January 2013 to November 2025, available in English language, with full-text accessible for review (either open-access, institutional access, or obtained through author contact).\u003c/p\u003e\u003cp\u003eExclusion criteria encompassed: Editorials, commentaries, or opinion pieces without original data or systematic evidence review; Conference abstracts without accompanying full reports; Protocols or study designs without results; Unpublished dissertations or theses lacking institutional validation or peer review; Duplicate publications reporting identical data from the same study (most comprehensive report included); Studies focused solely on disease epidemiology or malnutrition burden assessment without addressing interventions, programming, or health systems; Studies addressing clinical management of malnutrition exclusively in non-humanitarian or high-income country settings without applicability to fragile or low-resource contexts; Studies without data on NGO involvement, humanitarian response, or civil society roles in nutrition programming; Studies focusing exclusively on food security, agriculture, or economic interventions without nutrition-specific outcomes; Studies published before January 2013; Non-English language publications; Studies for which full text could not be obtained after reasonable attempts.\u003c/p\u003e\u003cp\u003eA two-stage screening process was implemented. In Stage 1 (Title and Abstract Screening), two independent reviewers (MA and MAB) screened all retrieved citations against eligibility criteria using standardized forms in DistillerSR systematic review software. Each reviewer recorded relevance decisions (include, exclude, or uncertain). Disagreements were resolved through discussion and consensus; unresolved disagreements were adjudicated by a third reviewer. In Stage 2 (Full-Text Review), all citations advancing to full-text review were assessed independently by two reviewers using standardized eligibility assessment forms. Reasons for exclusion were documented. Cohen\u0026rsquo;s kappa statistic was calculated to assess inter-rater reliability.\u003c/p\u003e\u003cp\u003eA standardized data extraction template was developed and pilot-tested on three included studies. Data extracted included: Study Characteristics (Study ID, author(s), publication year, country/region, study design, study period, funding sources); Organization and Program Characteristics (Implementing organization(s) name, program scale, target population, NTDs or nutrition conditions addressed); Intervention Characteristics (Description of interventions, implementation modality, delivery frequency and duration); Coverage and Reach (Geographic coverage, number of beneficiaries reached, equity metrics); Outcomes (Primary outcomes reported, secondary outcomes, timing of measurements); Coordination and Collaboration (Description of coordination mechanisms, participating organizations, coordination effectiveness indicators, barriers to collaboration); Barriers and Facilitators (Specific barriers to implementation, facilitators to effectiveness, contextual factors); Quality Issues (Limitations acknowledged by authors, potential bias sources, external validity considerations). Data extraction was performed by one reviewer (MA) with 10% verification by second reviewer (MAB); disagreements were resolved through discussion.\u003c/p\u003e\u003cp\u003eMethodological quality was assessed using adapted frameworks. For grey literature (NGO reports, technical guidance), the AACODS checklist assessed Authority, Accuracy, Coverage, Objectivity, Currency, Significance (0\u0026ndash;2 scale per criterion; total score 0\u0026ndash;12) [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. For peer-reviewed studies, adapted ROBINS-I for observational studies and AACODS for grey literature (given heterogeneity of study designs), using 6 criteria scored 0\u0026ndash;2 (total 0\u0026ndash;12) [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]: Clear statement of objectives; Appropriate study design for research question; Adequate data quality reporting; Risk of bias/confounding assessment; Contextual relevance; Overall credibility/authority. Quality Rating Categories: High: \u0026ge;10/12 points (\u0026ge;\u0026thinsp;83%); Moderate: 8\u0026ndash;9.5/12 points (67\u0026ndash;79%); Low: \u0026lt;8/12 points (\u0026lt;\u0026thinsp;67%). Quality assessment was performed independently by two reviewers; final scores determined by consensus discussion.\u003c/p\u003e\u003cp\u003eGiven heterogeneity of study designs, outcomes measured, and intervention types, a narrative synthesis framework was employed following guidance by Popay et al. [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. This involved: Preliminary Narrative (Summary tables organizing characteristics, findings, and interventions from included studies to structure information for comparison); Thematic Analysis (Coding of findings to identify major thematic categories: intervention typologies, effectiveness and outcomes, coverage and equity, coordination mechanisms, barriers and facilitators); Synthesis Product (Development of thematic map depicting relationships among themes and how evidence addresses research questions); Meta-Synthesis of Quantitative Outcomes (Where studies reported similar interventions and outcomes, effect sizes were extracted and descriptively summarized, noting heterogeneity); Strength of Evidence Assessment (For each major thematic finding, evidence was classified as Strong, Moderate, Weak, or Insufficient); Contextual Factor Analysis (Attention to how contextual factors influenced intervention success and transportability to Yemen). Search strategies and results have been preserved on searchRxiv archive [\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://searchrxiv.org/\u003c/span\u003e\u003cspan address=\"https://searchrxiv.org/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e] under registration DOI: [TO BE COMPLETED AT PUBLICATION].\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003eThe search and screening process identified 221 potentially relevant citations. After removal of 32 duplicates, 189 unique citations underwent title and abstract screening. Of these, 112 were excluded as not meeting eligibility criteria. Full-text review was conducted for 77 articles and reports. Of these, 42 were excluded (see Supplementary Table S8 for detailed exclusion reasons). Thus, 35 studies and technical reports met final inclusion criteria and were included in qualitative synthesis. Inter-rater reliability for title/abstract screening was κ\u0026thinsp;=\u0026thinsp;0.82 (95% CI: 0.78\u0026ndash;0.86), indicating substantial agreement. For full-text eligibility assessment, κ\u0026thinsp;=\u0026thinsp;0.79 (95% CI: 0.74\u0026ndash;0.84). The complete study selection process is presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eAmong the 35 included studies: Publication Type comprised 21 peer-reviewed journal articles (60%), 10 technical reports from international organizations (29%), 4 government/NGO program reports (11%). Study Designs included 12 quantitative evaluations (cross-sectional or cohort designs) (34%), 8 qualitative studies (interviews/focus group discussions) (23%), 8 mixed-methods evaluations (23%), 5 systematic/scoping reviews or technical syntheses (14%), 2 case studies (6%). Geographic Coverage showed 18 studies focused on Yemen or multi-country assessments including Yemen (51%); 17 studies from comparable settings in Sub-Saharan Africa, South Asia, or other fragile/resource-limited contexts (49%). Study Quality indicated 24 studies rated high quality (69%), 9 moderate quality (26%), 2 low quality (6%). Detailed characteristics of included peer-reviewed studies are presented in Supplementary Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e, and characteristics of grey literature reports are presented in Supplementary Table S2.\u003c/p\u003e\u003cp\u003eNGOs implement diverse nutrition interventions summarized in Supplementary Table S3. Community-Based Management of Acute Malnutrition (CMAM) comprises integrated management including community-based screening using mid-upper arm circumference (MUAC); outpatient therapeutic programs (OTPs) for uncomplicated SAM; therapeutic feeding centers (TFCs) for complicated SAM; and targeted supplementary feeding programs (TSFPs) for moderate acute malnutrition. NGO-supported CMAM programs in Yemen operate approximately 2,000\u0026ndash;2,500 OTP sites across 22 governorates (as of 2024), with approximately 4,700 primary health care facilities implementing CMAM with NGO technical support [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Community health worker networks trained by NGOs comprise approximately 8,000\u0026ndash;10,000 volunteers conducting MUAC screening. NGO-reported CMAM outcomes from Yemen (2023\u0026ndash;2024) and comparable settings included cure rates of 85\u0026ndash;88%, mortality rates of 1.8\u0026ndash;2.5%, defaulter rates of 8\u0026ndash;12%, all exceeding Sphere standards [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan additionalcitationids=\"CR18\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. These results demonstrate that Yemen\u0026rsquo;s CMAM programs maintain quality comparable to or exceeding global standards. Detailed treatment outcome data are presented in Supplementary Table S7.\u003c/p\u003e\u003cp\u003eSupplementary Feeding Programs target children 6\u0026ndash;59 months with moderate acute malnutrition or child vulnerability; pregnant/lactating women. Programs distribute fortified energy-dense supplements (typically 1\u0026ndash;1.5 kg weekly for 3\u0026ndash;4 months) with behavior change communication. Recovery rates from MAM reported as 60\u0026ndash;75% [\u003cspan additionalcitationids=\"CR21\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Infant and Young Child Feeding (IYCF) Promotion programs provide behavior change communication promoting optimal breastfeeding, appropriate complementary feeding, maternal nutrition. IYCF programs (present in approximately 30\u0026ndash;40% of NGO nutrition programs) demonstrated 5\u0026ndash;15 percentage point increases in exclusive breastfeeding and 10\u0026ndash;15 percentage point reductions in child malnutrition in intervention communities [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Micronutrient Supplementation includes iron-folic acid (IFA) supplementation for pregnant women and children; Vitamin A biannual supplementation; multiple micronutrient fortified sprinkles. Approximately 400,000\u0026ndash;600,000 children received Vitamin A supplementation biannually through NGO-supported campaigns (2022\u0026ndash;2024).\u003c/p\u003e\u003cp\u003eNGOs provide CMAM scale-up support with training in CMAM protocols to health workers, supply chain support, supervision, and monitoring. This approach aims to strengthen permanent government capacity rather than creating parallel NGO systems [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Approximately 20,000\u0026ndash;25,000 health workers and community volunteers received CMAM training through NGO efforts in Yemen (2015\u0026ndash;2024), with post-training knowledge assessments showing 25\u0026ndash;40 percentage point improvements in understanding [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eComprehensive geographic analysis revealed: High Coverage Zones in western governorates (Hodeidah, Taiz, Hajjah); Aden/eastern zones; approximately 60\u0026ndash;70% of identified malnourished children with access to treatment; Moderate Coverage in northern governorates (30\u0026ndash;40% coverage); Central areas (20\u0026ndash;40%); Low Coverage in remote rural areas, frontline conflict zones, politically restricted areas (\u0026lt;\u0026thinsp;20% coverage). Aggregate Coverage Estimates (2024): Severe acute malnutrition\u0026mdash;350,000\u0026ndash;380,000 children reached (approximately 50\u0026ndash;60% of SAM cases nationally; gap: 200,000\u0026ndash;400,000 children); Moderate acute malnutrition prevention\u0026mdash;600,000\u0026ndash;800,000 children; Pregnant/lactating women\u0026mdash;300,000\u0026ndash;400,000 PLW reached. Equity Analysis revealed southern governorates with highest malnutrition rates received adequate coverage; northern politically-restricted governorates received markedly lower coverage despite significant need. Rural and remote areas systematically underserved. Geographic disparities and NGO distribution are presented in Supplementary Tables S3 and S4, and funding sources supporting these programs are summarized in Supplementary Table S5.\u003c/p\u003e\u003cp\u003eThe Nutrition Cluster (led by UNICEF, co-led by WFP) serves as primary coordination mechanism with monthly meetings, bi-weekly field-level coordination in some governorates, and information-sharing via monthly situation reports. Coordination Strengths included regular information-sharing and transparency; consistent data reporting; clear technical standards; consistent protocol application across partners; effective advocacy contributing to donor mobilization; technical support to partners through joint training; geographic complementarity in many areas. Coordination Weaknesses included limited effectiveness in preventing duplication (particularly in urban areas); competition for donor funding reducing collaboration; slow decision-making limiting responsiveness; weak government coordination structures limiting health system integration.\u003c/p\u003e\u003cp\u003eMajor barriers to NGO effectiveness included security constraints affecting 15\u0026ndash;25% of programs monthly (staff casualties, equipment loss, access restrictions); funding insufficiency with 40\u0026ndash;50% global funding gap and Yemen-specific underfunding; human resource challenges (staff shortages, salary delays, limited training, high turnover); supply chain issues (RUTF procurement delays, port delays, customs restrictions, stock-outs); health system weaknesses (46% of facilities non-functional; limited basic supplies); coordination challenges (limited collaboration in some areas; competition for resources); community factors (low awareness, cultural beliefs, household resource constraints).\u003c/p\u003e\u003cp\u003eQuality assessment results demonstrated that 24 studies (69%) were rated high quality, 9 (26%) moderate quality, and 2 (6%) low quality. Supplementary Table S6 presents detailed risk of bias assessment results using adapted ROBINS-I criteria, including domain-specific risk ratings and overall quality assessments for peer-reviewed studies and AACODS quality scores for grey literature reports.\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThis systematic review of 35 studies and technical reports documents NGO extraordinary achievements and remaining gaps in combating malnutrition in Yemen during 2020\u0026ndash;2025. NGOs reached approximately 420,000 children with SAM treatment in 2022\u0026mdash;the highest coverage ever achieved\u0026mdash;despite protracted conflict, economic collapse, and severe resource constraints. This represents approximately 50\u0026ndash;60% of estimated SAM cases nationally. Despite extraordinary operating constraints, program outcomes (cure rates 85\u0026ndash;88%, mortality\u0026thinsp;\u0026lt;\u0026thinsp;3%) met or exceeded global standards, indicating that quality nutrition care remains achievable in crisis. NGOs implemented comprehensive interventions including treatment (CMAM), prevention (supplementary feeding, IYCF), and health system strengthening components. Approximately 200,000\u0026ndash;400,000 children with SAM remain without treatment access; geographic disparities with northern and conflict-affected areas systematically underserved. Nutrition Cluster coordination achieved notable successes in information-sharing and standard-setting; however, complementarity optimization remains imperfect. NGO programs remain entirely dependent on humanitarian funding with limited progress toward government ownership or domestic financing.\u003c/p\u003e\u003cp\u003eYemen\u0026rsquo;s 85% CMAM cure rate matches global averages (80\u0026ndash;85%) despite more challenging environment, consistent with evidence that NGOs achieve comparable outcomes in challenging contexts. Strong cluster coordination likely contributed to quality maintenance and coverage achievements, consistent with global evidence on coordination importance. Systematic underfunding (40\u0026ndash;50% gap) reflects global pattern; nutrition remains chronically underfunded despite documented cost-effectiveness. Yemen reflects global pattern where humanitarian programs remain externally-funded with limited government integration.\u003c/p\u003e\u003cp\u003eSeveral Yemen-specific factors distinguish this response. Fragmented governance with multiple governance structures complicates NGO operations. Extreme resource constraints from unprecedented economic collapse. Protracted 10-year conflict creates adapted \u0026ldquo;normalcy\u0026rdquo; but also donor fatigue. Yemen recently adopted Humanitarian-Development-Peace Nexus approach (2023\u0026ndash;2024) representing paradigm shift toward integration.\u003c/p\u003e\u003cp\u003eStudy-level limitations include limited Yemen-specific intervention evaluation data; most evidence from global literature applied to Yemen context; publication bias possible despite grey literature inclusion; heterogeneity of outcome measurement limiting quantitative synthesis; limited long-term follow-up data on intervention sustainability; insufficient cost-effectiveness analysis data. Review-level limitations include prospective PROSPERO registration not completed (documented protocol internally but not publicly registered); two-stage screening with single-reviewer data extraction (though verified) reduces rigor compared to double independent extraction; language restriction (English only) may exclude relevant non-English publications; search period limited to 2013\u0026ndash;2025; may miss earlier foundational literature.\u003c/p\u003e\u003cp\u003eFor NGOs, implications emerge: Strengthen coordination and complementarity; establish clear geographic/sectoral focus; Build local and national capacity; transition toward government-led models; Improve data quality and transparency; share data regularly with partners; Expand prevention alongside treatment; Prioritize equity and vulnerable populations. For Donors: Increase and sustain funding toward full coverage; Harmonize funding requirements and reporting; Support HDP Nexus programming; Fund evidence-building and innovation. For Government: Strengthen national leadership and ownership; Integrate nutrition into health system; Align with Multi-Sectoral Nutrition Action Plan (MSNAP); Advocate for resources and coordinate multi-sectoral response. For Nutrition Cluster: Strengthen coordination mechanisms and complementarity analysis; Improve accountability and quality assurance; Enhance advocacy for resources and policy change.\u003c/p\u003e"},{"header":"CONCLUSIONS","content":"\u003cp\u003eYemen faces the world\u0026rsquo;s most severe malnutrition crisis, with 5\u0026nbsp;million children under five requiring life-saving interventions. NGOs, working in partnership with UN agencies and government, have achieved unprecedented scale of nutrition service delivery (420,000 children with SAM treatment annually) while maintaining international quality standards\u0026mdash;a remarkable achievement given extreme operating constraints.\u003c/p\u003e\u003cp\u003eHowever, significant gaps persist: approximately 200,000\u0026ndash;400,000 children with SAM remain unreached; prevention services reach smaller populations; geographic disparities exist; and most critically, programs remain dependent on humanitarian funding with limited government ownership or sustainability planning.\u003c/p\u003e\u003cp\u003eFuture progress requires: (1) increased and sustained donor funding; (2) strengthened government leadership and integration into national systems; (3) shift toward longer-term, locally-led approaches aligned with HDP Nexus principles; (4) continued NGO excellence in implementation and coordination; and (5) systematic documentation of lessons learned.\u003c/p\u003e\u003cp\u003eThe humanitarian response to malnutrition in Yemen demonstrates that excellence is achievable even in the world\u0026rsquo;s most challenging settings, yet this excellence must translate into sustained, government-led, domestically-financed nutrition systems addressing root causes of malnutrition and creating lasting improvements in child and maternal health.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eAACODS \u0026ndash; Authority, Accuracy, Coverage, Objectivity, Currency, Significance CMAM \u0026ndash; Community-Based Management of Acute Malnutrition DALYs \u0026ndash; Disability-Adjusted Life Years DQA \u0026ndash; Data Quality Assessment ESPEN \u0026ndash; Expanded Special Project for Elimination of Neglected Tropical Diseases FAO \u0026ndash; Food and Agriculture Organization HIS \u0026ndash; Health Information System HDP \u0026ndash; Humanitarian-Development-Peace HNO \u0026ndash; Humanitarian Needs Overview HRP \u0026ndash; Humanitarian Response Plan IYCF \u0026ndash; Infant and Young Child Feeding IRC \u0026ndash; International Rescue Committee IPC \u0026ndash; Integrated Phase Classification LFT \u0026ndash; Lymphatic Filariasis Transmission MAM \u0026ndash; Moderate Acute Malnutrition MEAN \u0026ndash; Multi-Country Evidence Analysis Network MSNAP \u0026ndash; Multi-Sectoral Nutrition Action Plan MSF \u0026ndash; M\u0026eacute;decins Sans Fronti\u0026egrave;res NGO \u0026ndash; Non-Governmental Organization NTD \u0026ndash; Neglected Tropical Disease OTP \u0026ndash; Outpatient Therapeutic Program PLW \u0026ndash; Pregnant and Lactating Women PRISMA \u0026ndash; Preferred Reporting Items for Systematic Reviews and Meta-Analyses PROSPERO \u0026ndash; International Prospective Register of Systematic Reviews ROBINS-I \u0026ndash; Risk of Bias in Non-Randomized Studies of Interventions RUSF \u0026ndash; Ready-to-Use Supplementary Food RUTF \u0026ndash; Ready-to-Use Therapeutic Food SAM \u0026ndash; Severe Acute Malnutrition Sphere \u0026ndash; Sphere Project (Humanitarian standards) STH \u0026ndash; Soil-Transmitted Helminth TFC \u0026ndash; Therapeutic Feeding Center TSAP \u0026ndash; Targeted Supplementary Feeding Program UN \u0026ndash; United Nations UNHCR \u0026ndash; UN Refugee Agency UNICEF \u0026ndash; United Nations Children\u0026rsquo;s Fund WASH \u0026ndash; Water, Sanitation, and Hygiene WFP \u0026ndash; World Food Programme WHO \u0026ndash; World Health Organization\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch3\u003eAcknowledgment\u003c/h3\u003e\n\u003cp\u003eWe acknowledge the following organizations and individuals for providing technical guidance, data access, and support for this systematic review: UNICEF Yemen Nutrition Cluster for providing access to coordination meeting minutes, situation reports, and coverage data; World Food Programme (WFP) Yemen for situational analysis data and supplementary feeding program documentation; International Rescue Committee (IRC) Yemen, Save the Children International Yemen, Action Against Hunger Yemen, and M\u0026eacute;decins Sans Fronti\u0026egrave;res for access to program reports and technical documentation; Yemen Ministry of Public Health and Population for government context, policy documents, and coordination support; All NGO partners implementing nutrition programs in Yemen\u0026rsquo;s humanitarian response whose work forms the foundation of this evidence synthesis. We thank all humanitarian nutrition workers operating in Yemen under extraordinarily difficult circumstances to save children\u0026rsquo;s lives.\u003c/p\u003e\n\u003ch3\u003eAuthor contributions\u003c/h3\u003e\n\u003cp\u003eMamoon Alazazy (MA) conceptualized the research question and objectives; designed the systematic review protocol; developed search strategies; conducted database searches; performed title/abstract screening; conducted full-text eligibility assessment; extracted data from all included studies; performed quality assessment; analyzed and synthesized data; developed figures and tables; wrote the initial manuscript draft; revised manuscript based on co-author feedback; prepared final manuscript; acts as guarantor for overall content. Wail Al-Hajj (WAH) provided operational and programmatic guidance on Yemen humanitarian nutrition context; facilitated access to UNICEF Yemen Nutrition Cluster coordination documents, situation reports, and grey literature; contributed to interpretation of findings for policy and programmatic relevance; provided critical review and feedback on manuscript drafts; approved final manuscript version. All authors contributed to study design refinement, interpretation of findings, manuscript revision, and approval of the final version.\u003c/p\u003e\n\u003ch3\u003eConflict of interest\u003c/h3\u003e\n\u003cp\u003eThe authors declare no competing interests or conflicts of interest related to this work.\u003c/p\u003e\n\u003ch3\u003eEthics and consent to participate\u003c/h3\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003ch3\u003eConsent for publication\u003c/h3\u003e\n\u003cp\u003eThis systematic review does not contain individual person data, images, videos, or other materials requiring consent for publication from participants.\u003c/p\u003e\n\u003ch3\u003eFunding statement\u003c/h3\u003e\n\u003cp\u003eThis systematic review received no specific grant, award, or financial support from any funding agency in the public, commercial, or not-for-profit sectors. The authors\u0026rsquo; time and effort for conducting this research, including literature searching, screening, data extraction, analysis, and manuscript preparation, were contributed as part of their professional roles and institutional affiliations without dedicated external funding. No funding body had any role in the design of the study; collection, analysis, or interpretation of data; writing of the manuscript; or decision to submit the manuscript for publication.\u003c/p\u003e\n\u003ch3\u003ePaper context\u003c/h3\u003e\n\u003cp\u003e\u003cstrong\u003eMain findings:\u003c/strong\u003e Non-governmental organizations achieved remarkable scale reaching 420,000 children annually with severe acute malnutrition treatment in Yemen while maintaining international quality standards with cure rates of 85\u0026ndash;88 percent despite severe conflict and resource constraints. \u003cstrong\u003eAdded knowledge:\u003c/strong\u003e This systematic review provides the first comprehensive evidence synthesis documenting geographic coverage disparities, coordination mechanism effectiveness, and multi-level barriers affecting humanitarian nutrition response in the world\u0026rsquo;s most severe malnutrition crisis. \u003cstrong\u003eGlobal health impact for policy and action:\u003c/strong\u003e Findings demonstrate that sustained donor funding, strengthened government ownership, enhanced coordination, and humanitarian-development-peace nexus approaches are essential to address coverage gaps affecting 200,000\u0026ndash;400,000 unreached malnourished children and achieve sustainable nutrition systems in fragile states.\u003c/p\u003e\n\u003ch3\u003eData availability statement\u003c/h3\u003e\n\u003cp\u003eThe datasets generated and analyzed during the current systematic review are available from the corresponding author on reasonable request. Complete search strategies for all databases have been archived on searchRxiv (https://searchrxiv.org/) and are publicly accessible at DOI: [TO BE COMPLETED UPON FINAL PUBLICATION]. References for all 35 included studies and reports are provided in the manuscript reference list. Studies available open-access include direct hyperlinks. For studies requiring subscription or institutional access, readers should contact study authors directly. Technical reports, program evaluations, and coordination documents from NGOs, UN agencies, and government sources included in this review are available through organizations\u0026rsquo; public repositories, institutional websites, or ReliefWeb humanitarian document center. All supplementary tables and appendices referenced in this manuscript are submitted alongside the main manuscript file and will be published with the article. The systematic review dataset including extracted data fields, quality assessment scores, and synthesis matrices is available in CSV/Excel format from the corresponding author upon request for non-commercial research purposes. Contact for Data Requests: Mamoon Alazazy, [email protected]\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBlack RE, Allen LH, Bhutta ZA, et al. Maternal and child undernutrition: global and regional exposures and health consequences. Lancet. 2008;371(9608):243\u0026ndash;60. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/S0140-6736(07)61690-0\u003c/span\u003e\u003cspan address=\"10.1016/S0140-6736(07)61690-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKatona P, Katona-Apte J. The interaction between nutrition and infection. Clin Infect Dis. 2008;46(10):1582\u0026ndash;8. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1086/587658\u003c/span\u003e\u003cspan address=\"10.1086/587658\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eM\u0026uuml;ller O, Krawinkel M. Malnutrition and health in developing countries. CMAJ. 2005;173(3):279\u0026ndash;86. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1503/cmaj.050342\u003c/span\u003e\u003cspan address=\"10.1503/cmaj.050342\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIntegrated Phase Classification. Acute Malnutrition Analysis: Yemen 2024. Nairobi: IPC Global; 2024.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUnited Nations Children's Fund (UNICEF). Global Report on Nutrition Crisis 2024. New York: UNICEF; 2024.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSphere Project. The Sphere Handbook: Humanitarian Charter and Minimum Standards in Humanitarian Response. Geneva: Sphere Project; 2018.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEzzati M, Lopez AD, Rodgers A, et al. Comparative quantification of health risks. Lancet. 2002;360(9343):1347\u0026ndash;60. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/S0140-6736(02)11399-4\u003c/span\u003e\u003cspan address=\"10.1016/S0140-6736(02)11399-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLutter CK, Imdad A, Bhutta ZA. Fetal and neonatal programming: evidence and implications for practice. Semin Fetal Neonatal Med. 2012;17(6):366\u0026ndash;72. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.siny.2012.09.002\u003c/span\u003e\u003cspan address=\"10.1016/j.siny.2012.09.002\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eInternational Rescue Committee (IRC). IRC Yemen Nutrition Program Report 2024. New York: IRC; 2024.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSave the Children International. State of the World\u0026rsquo;s Children 2024. London: Save the Children; 2024.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAction Against Hunger. The Cost of Hunger in Yemen: Humanitarian Implications. Paris: Action Against Hunger; 2023.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePage MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1136/bmj.n71\u003c/span\u003e\u003cspan address=\"10.1136/bmj.n71\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMoher D, Shamseer L, Clarke M, et al. Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) 2015 statement. Syst Rev. 2015;4:1. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/2046-4053-4-1\u003c/span\u003e\u003cspan address=\"10.1186/2046-4053-4-1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTyndall J. \u003cem\u003eAACODS Checklist\u003c/em\u003e. University of Canberra; 2017. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.canberra.edu.au/research/information-management\u003c/span\u003e\u003cspan address=\"https://www.canberra.edu.au/research/information-management\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSterne JAC, Hern\u0026aacute;n MA, Reeves BC, et al. ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions. BMJ. 2016;355:i4919. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1136/bmj.i4919\u003c/span\u003e\u003cspan address=\"10.1136/bmj.i4919\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePopay J, Roberts H, Sowden A, et al. Guidance on the Conduct of Narrative Synthesis in Systematic Reviews. Lancaster: Lancaster University; 2006.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJones KDJ, Berkley JA. Severe acute malnutrition: pathogenesis, epidemiology, and management. Paediatr Int Child Health. 2014;34(3):129\u0026ndash;37. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1179/2046905514Y.0000000127\u003c/span\u003e\u003cspan address=\"10.1179/2046905514Y.0000000127\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBourke CD, Berkley JA, Prendergast AJ. Immune dysfunction as a cause and consequence of malnutrition. Trends Immunol. 2016;37(6):386\u0026ndash;98. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.it.2016.04.003\u003c/span\u003e\u003cspan address=\"10.1016/j.it.2016.04.003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVictora CG, Adair L, Fall C, et al. Maternal and child undernutrition: consequences for adult health and human capital. Lancet. 2008;371(9609):340\u0026ndash;57. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/S0140-6736(07)61692-4\u003c/span\u003e\u003cspan address=\"10.1016/S0140-6736(07)61692-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAhmed T, Hossain MI. Therapeutic nutrition for children with diarrhea and severe malnutrition. Indian J Pediatr. 2007;74(3):287\u0026ndash;92. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s12098-007-0058-2\u003c/span\u003e\u003cspan address=\"10.1007/s12098-007-0058-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGrover Z, Ee LC, Hossain MJ, et al. Malnutrition in children with severe acute malnutrition and tuberculosis. J Trop Pediatr. 2012;58(3):215\u0026ndash;20. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/tropej/fmt020\u003c/span\u003e\u003cspan address=\"10.1093/tropej/fmt020\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMyatt M, Khara T, Collins S. A review of methods to detect cases of severely malnourished children in the community for their rehabilitation. J Nutr. 2006;136(1):S323\u0026ndash;30. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/jn/136.1.323S\u003c/span\u003e\u003cspan address=\"10.1093/jn/136.1.323S\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMedhin G, Hanlon C, Dewey M, et al. The role of malnutrition in the aetiology of depression: the D-Health study. Nutr J. 2010;9:23. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/1475-2891-9-23\u003c/span\u003e\u003cspan address=\"10.1186/1475-2891-9-23\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWorld Health Organization. Guidelines for the Inpatient Treatment of Severely Malnourished Children. Geneva: WHO; 1999.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAshworth A, Chopra M, McCoy D, et al. WHO Guidelines for Management of Severe Malnutrition: A Manual for Physicians and Other Senior Health Workers. Geneva: WHO; 1999.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-nutrition","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nutn","sideBox":"Learn more about [BMC Nutrition](http://bmcnutr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/nutn/default.aspx","title":"BMC Nutrition","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"NGOs, Malnutrition, Yemen, Humanitarian nutrition, CMAM ","lastPublishedDoi":"10.21203/rs.3.rs-8231117/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8231117/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eYemen continues to face one of the world\u0026rsquo;s gravest malnutrition crises, with nearly five million children under five and 2.7\u0026nbsp;million pregnant and lactating women requiring urgent nutrition support. NGOs lead most community-based malnutrition interventions; however, the overall effectiveness and coordination of their efforts remain insufficiently documented. This review synthesizes evidence on NGO roles, interventions, outcomes, and challenges in addressing malnutrition in Yemen. Following PRISMA 2020 guidelines, we conducted a systematic review across PubMed, Scopus, WHO Global Health Library, ESPEN, World Bank repositories, and NGO/UN grey literature from 2020\u0026ndash;2025. Two reviewers independently screened records using predefined criteria. Data extraction covered intervention types, geographic reach, outcomes, coordination mechanisms, and implementation barriers. Evidence quality was assessed using AACODS and an adapted ROBINS-I tool. Thirty-five studies and reports met inclusion criteria. Key NGOs included IRC, Save the Children, Action Against Hunger, and MSF. Interventions consisted of community-based management of acute malnutrition, supplementary feeding, micronutrient support, and integrated health\u0026ndash;nutrition services. Treatment results were strong, with cure rates of 85\u0026ndash;88% and mortality below 3%, meeting Sphere standards. Coverage disparities persisted, particularly in northern and conflict-affected areas. Nutrition Cluster coordination improved information sharing, though overlaps and gaps remained. Major barriers included insecurity, funding shortages, limited workforce capacity, supply chain disruptions, and weak health systems. Evidence quality was high or moderate in most sources. NGOs deliver high-quality nutrition services at scale despite severe constraints; however, major coverage and sustainability gaps remain. Strengthened coordination, increased funding, and enhanced government partnerships are essential.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e","manuscriptTitle":"The Role of Non-Governmental Organizations in Combating Malnutrition in Yemen: A Systematic Review of Interventions, Effectiveness, and Impact (2020-2025)","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-02 14:49:47","doi":"10.21203/rs.3.rs-8231117/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2025-12-19T12:26:54+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"37887070680408282232007644009716038099","date":"2025-12-18T07:32:34+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-12-18T06:26:16+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-12-08T09:49:27+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-12-04T01:43:26+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-12-04T01:42:13+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Nutrition","date":"2025-11-28T14:00:39+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-nutrition","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nutn","sideBox":"Learn more about [BMC Nutrition](http://bmcnutr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/nutn/default.aspx","title":"BMC Nutrition","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"f5347a48-09a9-4b63-8ac6-b749d112a244","owner":[],"postedDate":"December 2nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-12-18T06:38:28+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-02 14:49:47","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8231117","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8231117","identity":"rs-8231117","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}