Can higher-calorie feeding protocols for patients with eating disorders admitted to an adult hospital ward be safely implemented to reduce the length of stay? A scoping review

Can higher-calorie feeding protocols for patients with eating disorders admitted to an adult hospital ward be safely implemented to reduce the length of stay? 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A scoping review Jackson Taylor, Michael Salmon, Caitlin Rogash, Grace Branjerdporn This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8537410/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 15 You are reading this latest preprint version Abstract Background: Hospital admissions for individuals with eating disorders are increasing, yet adult inpatient nutritional restoration often relies on conservative low-calorie refeeding to avoid refeeding syndrome (RFS). Evidence from younger populations suggests that higher-calorie refeeding (HCR) may be safe and more efficient, but data from adults are limited. This scoping review mapped the extent, characteristics and safety of HCRs (≥1500 kcal/day) for people with eating disorders admitted to adult hospital wards. Methods: Five electronic databases were searched from July 2025 for studies published from January 2012–June 2025. Eligible studies included adults with a diagnosed eating disorder or mixed-age samples treated in adult wards, who underwent HCR on admission. The primary outcomes were RFS markers, particularly refeeding hypophosphataemia; the secondary outcomes were length of stay (LOS), weight gain and change in body mass index (BMI). Three reviewers independently screened the records and charted the data, and the findings were synthesised descriptively. Results: Of the 778 records identified, 11 studies met the inclusion criteria. Most of these studies involved retrospective cohorts, with three quasi-experimental before–after designs, which were performed in adult specialist or general inpatient settings across several countries. Together, they described 4,874 patients exposed to HCR, usually starting at 1,500–2,000 kcal/day and advancing as tolerated. Definitions and monitoring of RFS vary widely. No study reported deaths or clinically defined RFS attributable to HCR. Biochemical hypophosphataemia affects up to approximately one-third of patients, is usually mild and is managed with electrolyte supplementation. Four studies reported LOS; two reported shorter admissions and faster weight gain with HCR than with lower-calorie protocols did. Conclusions: Across observational studies, initiating HCR for people with eating disorders in adult hospital wards appears feasible and can be delivered without an obvious increase in clinical RFS while potentially reducing the LOS and enhancing weight restoration when combined with close monitoring and supplementation. Heterogeneity in RFS definitions, refeeding protocols and outcome reporting, and the absence of randomised trials limit confidence in these findings. Prospective studies using standardised RFS criteria and clearly defined HCR and comparator protocols are needed to guide adult-focused practice and policy. Trial registration: Not applicable. Eating disorders Anorexia nervosa Adults Inpatients High calorie refeeding Low-calorie refeeding Refeeding syndrome Length of stay Figures Figure 1 Plain English Summary People admitted to the hospital for an eating disorder often need careful “refeeding” to restore nutrition. Many services still start with low-calorie feeding and increase slowly to avoid a rare but serious complication called refeeding syndrome (dangerous shifts in body electrolytes and fluids). However, newer studies—mostly in younger patients—have suggested that starting with more calories, alongside close blood test monitoring and vitamin/mineral supplements, may be just as safe and could help people recover faster and leave the hospital sooner. This scoping review maps what is known about higher- versus lower-calorie refeeding in adult hospital wards. We will compare safety (refeeding syndrome and low blood phosphate), length of stay, and weight or body mass index changes. Because studies use different definitions and monitoring routines, we will record exactly how each study measured these outcomes so that the findings can be compared fairly. The results can help clinicians, patients, and services obtain a clear overview of the evidence to support safe, timely, and effective inpatient nutritional care. Background Eating disorders (EDs) are severe psychiatric illnesses marked by persistent disturbances in eating behaviours and body image, often driven by weight and shape concerns (1). Diagnoses include anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED), and avoidant/restrictive food intake disorder (ARFID). EDs cause profound psychological distress and medical morbidity, with AN resulting in the highest mortality of any psychiatric disorder, most often due to suicide or complications of prolonged malnutrition (2). In Australia, up to 16% of adults will experience an ED in their lifetime (3). Hospital admissions for EDs increased by 91% between 2008 and 2018, with an average length of stay (LOS) of 21 days (4). Many patients are admitted following prolonged starvation and are considered at risk of refeeding syndrome (RFS), a potentially life-threatening cluster of electrolyte and fluid disturbances triggered by nutritional rehabilitation (5). Concern about RFS has historically led services to adopt conservative “low and slow” refeeding protocols in the first 24–48 hours of admission. RFS was first described in the Minnesota Starvation Experiment, which documented metabolic changes during the refeeding of semi-starved men (6). Although influential, the study has ethical and methodological limitations and offers little guidance for contemporary ED care. International guidelines such as the National Institute for Health and Care Excellence (NICE) (7) define generic risk criteria, but these lack specificity for ED populations. More recent consensus statements, including the 2025 Australasian Society for Parenteral and Enteral Nutrition (AuSPEN) guidance, recommend against the routine use of “start low, go slow” approaches and instead advocate progression to full nutritional requirements within the first 24–72 hours, supported by structured monitoring and prophylactic supplementation (8). Conservative low-calorie refeeding (LCR) aims to prevent RFS but may prolong catabolism, limit early weight gain, and extend LOS, potentially exacerbating bradycardia, hypotension, and fatigue that delay therapy engagement (9). In contrast, higher-calorie refeeding (HCR) protocols, when combined with careful monitoring, appear equally safe and more effective (10). In adolescents, a multicentre randomised trial revealed no difference in RFS, readmission, or mortality between HCR and LCR, but HCR achieved faster weight restoration (11). Systematic reviews in paediatric and young adult cohorts similarly reported a reduced LOS and no excess mortality with HCR, irrespective of disease severity (12). By comparison, the adult evidence base is sparse. Australian clinical practice guidelines currently recommend a cautious “middle path” initiation of ~1400 kcal/day, reflecting uncertainty about how to balance RFS risk against the harms of underfeeding (13). Emerging adult studies suggest that increased starting prescriptions may be safe in those with mild to severe malnutrition (14). A recent prospective observational study of adults admitted to medical and psychiatric wards revealed that the HCR was not associated with increased clinical RFS and appeared to support a shorter LOS and greater weight restoration, but outcome reporting and protocol details varied (15). Across adult studies, definitions of RFS, thresholds for biochemical abnormalities (e.g., hypophosphataemia), and measures of weight gain or body mass index (BMI) change are inconsistent, limiting synthesis and clinical translation (16). Another key consideration is that many late adolescents and young adults with EDs transition from child and youth services to adult hospital wards during a period of changing legal status and autonomy. Treatment models and expectations often differ across these settings, and disengagement rates are high (17). Because these individuals are frequently managed within adult inpatient units and subject to adult refeeding protocols, understanding the safety and outcomes of HCR in these environments is essential to ensure that continuity of care can be provided across paediatric and adult service lines to support this transitional phase (18). Aims of the review This scoping review was designed to address the lack of clear, adult-focused evidence comparing high-calorie refeeding (HCR) and low-calorie refeeding (LCR) in inpatient eating disorder care. Adult studies remain heterogeneous, with inconsistent definitions of refeeding syndrome (RFS), variable reporting of length of stay (LOS), and non-standardised measures of weight gain and BMI change. These uncertainties limit clinical decision-making and highlight the need for systematic evidence mapping before formal effectiveness trials can be undertaken. Accordingly, this review aims to explore the existing evidence regarding HCR versus LCR protocols in adult hospital wards treating people with eating disorders, including late adolescents and young adults admitted to adult services. Specifically, it seeks to answer the following research questions: What is the existing evidence on the occurrence of RFS when initiating HCR compared with LCR for eating disorder consumers admitted to adult hospital wards? Does initiating HCR protocols, unlike LCR protocols, for eating disorder consumers in an adult inpatient ward influence the length of stay? Does initiating HCR protocols rather than LCR protocols for eating disorder consumers in an adult inpatient ward influence the rate of weight gain or BMI changes during admission? Methods Protocol and registration: This scoping review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines from the latest Joanna Briggs Institute (JBI) guidance for scoping review (19). Search strategy: The MEDLINE, CINAHL, American Psychological Association (APA) PsycArticles, ProQuest and Scopus electronic databases were used to conduct systematic literature searches. The search strategy, including the databases, key search terms, and number of articles identified via this method, is shown in Supplementary 1. The search was undertaken during July 2025 and was limited to articles published between 1 Jan 2012 and 30 June 2025, as high-calorie refeeding remains a relatively novel approach. Potential additional studies were identified through snowballing; the reference lists of relevant systematic reviews, narrative reviews and meta-analyses identified in the “title/abstract” screening were searched in addition to the reference list of the QuEDs guidelines. Selection criteria: Eligibility criteria Eligibility was based on the PIO criteria: population, issues and outcomes to structure the question and guide. Papers that met the following criteria were included: Patients previously had a diagnosis of an eating disorder [anorexia nervosa, bulimia nervosa, binge eating disorder, avoidant and restrictive food intake disorder (ARFID)]. Patients were admitted to an adult inpatient unit (e.g., general medical, psychiatric, or specialist inpatient unit for eating disorder treatment). HCRs ≥1500 calories/day were initially received as part of the nutrition intervention Population: Studies including individuals of any age or sex who received HCR due to an eating disorder with a diagnosis of AN, BN, EDNOS, OSFED, or ARFID within an adult hospital setting requiring nutritional restoration. Studies were excluded if they were conducted in a paediatric unit or a young adult unit that excluded adult Eating Disorder Consumers (EDCs) on the basis of age (e.g., not providing care to those > 18 years of age). Issue: Higher caloric refeeding (HCR) rates of ≥1500 calories/day are needed for eating disorder patients admitted to an inpatient adult ward. Outcomes: Studies were eligible if they mentioned at least one primary measure related to refeeding syndrome markers during hospital admission. Examples of such markers included hypophosphataemia, hypokalaemia, hypomagnesaemia, peripheral oedema or a combination of these. The secondary outcomes of interest, including length of stay, rate of weight gain and changes in admission and discharge body mass indices (BMIs), were also reported, although these were not necessary inclusion criteria. Study design: The studies included were randomised controlled trials, case‒controlled studies, and observational and cohort studies. Case studies, qualitative studies, abstracts of poster presentations, theses and gray literature were excluded. Screening process Title and abstract screening of all records was performed by three reviewers (JT, CR, MS), with one author as the first rater (JT) and the second rater shared between the other two authors (MS, CR) via web-based systematic review software (Covidence). Raters independently assessed the eligibility of the articles that were identified following the database search based on the eligibility criteria. Duplicates were removed from Covidence and manually checked. Records that appeared to meet the inclusion criteria on the basis of title and abstract were retrieved for full-text review. Full-text screening was again performed independently by the same three reviewers, with discrepancies resolved through discussion and, where needed, majority consensus. Study selection: Data were extracted into an Excel spreadsheet created for review by all three authors who completed full-text screening, following an established framework for scoping reviews (20). The data extracted included the region of the study, type of study design, age of the participants with an eating disorder, refeeding protocol and incidence of refeeding syndrome. Each of the reviewers independently recorded the data, discussed the results and continuously updated the data-charting form in an iterative process. The data obtained from the included studies were confirmed on a majority basis. If no majority was reached, all three reviewers analysed the included papers together to reach a consensus. The main revisions through this process were charting if prophylactic supplementation was mentioned in the study protocol, as this may have influenced how HCR was conducted. Results Study Selection The systematic database search yielded 778 articles. Once duplicates (n = 275 articles) were removed, the abstracts and titles of 503 articles were screened for inclusion in this review. Most of the articles (n = 456) were excluded because of irrelevancy. The remaining 47 full-text articles were screened for inclusion in this review. A further 36 articles were excluded for predefined reasons such as paediatric-only settings (n=14) and incorrect interventions, such as initiating an LCR (n=7). One article identified via citation chaining (Matthews et al., 2018) was included, resulting in a total of eleven included papers. Figure 1 shows the modified PRISMA flow diagram in which the search yields are presented (21). Figure 1: PRISMA study flow diagram showing the study selection process. [Insert Figure 1 PRISMA table on new methodology] Summary of outcomes Table 1 summarises the findings of the eleven included studies, which were conducted in the United States, Germany, Australia, Canada and Switzerland. Most papers that met the inclusion criteria were observational and retrospective cohort studies, with three studies employing a quasi-experimental (before-after/natural-experiment) design (22-24). The mean ages across the included studies demonstrated substantial variation depending on the population sampled but clustered around the middle-to-late twenties for adult cohorts. The mean age ranged from 23.8 years (25) to 32.5 years (26) for studies focused on adult eating disorder consumers. Conversely, studies including paediatric and adolescent samples reported lower mean ages, such as 15.5 years (27), 17.3 years (22), and a median of 17 years (28). Six of the eleven studies sampled only consumers with an anorexia nervosa (AN) diagnosis (22-25, 27, 29). Eight studies were conducted in a specialised inpatient ward and setting for eating disorder consumers, whereas three papers were conducted in a general hospital inpatient setting (28, 30, 31). Table 1: Key methodological features and quantitative findings from the included studies (N = 11) [Insert Table 1: Key methodological features and quantitative findings from included studies (N = 11)] Abbreviations: AN = anorexia nervosa, BMI = body mass index, ED = eating disorder, HCR = high calorie refeeding, K = potassium, LCR = low calorie refeeding, LOS = length of stay, Mg = magnesium, PO4 = phosphate, RFS = refeeding syndrome, RH = refeeding hypophosphataemia, SD = standard deviation, Wt = weight The exclusion criteria varied across study designs by diagnosis, duration of hospitalisation, weight status, and concurrent medical conditions. Five papers focused solely on AN by excluding other eating-disorder diagnoses (22, 24, 25, 27, 30), whereas three included broader diagnoses (26, 28, 31). Length-of-stay (LOS)/retention-period exclusions are common: <24 h (28), <72 h (32), <5 days (31), and <7 days (23, 24, 30). Two cohorts required LOS ≥28 days (25, 29), and others reported no explicit LOS-related exclusion (22, 26, 27). Additional exclusions included pregnancy and non-ED medical comorbidities (23, 31). In all included studies, the number of female participants was proportionally greater than that of male participants, and Koerner et al. (25) reported that no males met the BMI <13 kg/m² inclusion threshold. Weight-status criteria across the eleven studies varied by metric (BMI vs. %IBW/%mBMI) and function (inclusion vs. exclusion). An explicit exclusion ceiling was used in Gibson et al. (32) (>65% IBW excluded), and a severe-underweight entry threshold was used in Koerner et al. (25) (BMI <13 kg/m²). Youth/mixed-age cohorts operationalise severity using the %mBMI (22, 26, 27, 30), whereas several adult or mixed cohorts report no explicit weight-based exclusion and rely on clinical admission pathways (23, 24, 29, 31). Where specified, some cohorts described very low BMI inclusion bands (e.g., <15 kg/m²) to characterise baseline severity. The observational study by Cuntz et al. (29) was the largest, with 3230 admissions in a 15-bed specialised inpatient ward for EDCs across four years. The smallest study included was that of Haynos et al. (23), which initially involved 70 EDCs in their quasi-experimental design and a subsample of 20 for secondary analysis of RFS occurrence. Across the eleven included studies, a total of 4,874 patients were analysed for the incidence of RFS. Study findings All eleven studies reported on hypophosphataemia, with eight papers measuring refeeding hypophosphataemia (RH), while one measured the incidence of refeeding in the presence of oedema only (23). Among the eight studies reporting on RH, there was heterogeneity between the definitions and severity thresholds (i.e., mild, critical). The cut-off for RH ranged from 0.75 mmol--0.91 mmol/L, whereas the critical RH ranged from 0.31--0.71 mmol/L. Two studies included in this analysis utilised the same cut-offs to establish their own criteria for refeeding syndrome occurrence (25, 29), while two studies defined it on the basis of the criteria of Rio et al. (33) (22, 24), and four studies cited criteria on the basis of the NICE guidelines (7, 26, 28, 30, 31). The other two studies with a lower mean age defined hypophosphataemia as <0.9 mmol/L in alignment with adolescent guidelines (27, 32). Only two of the eleven studies reported cases of RH (27, 32), with Gibson et al. (32) reporting that it occurred in 35% of their sample (5 males and 93 females), with 47% of these patients (3 males and 43 females) meeting their criteria for critical hypophosphataemia. There were no deaths or cases of refeeding syndrome reported in any of the included studies. When accounting for BMI, four papers reported that a lower admission BMI was significantly (p <.001) associated with an increased risk in predicting RH (23, 26, 32), with Cuntz et al. (29) reporting a highly significant and negative correlation (Spearman correlation 0.41, p <.000) between the two variables. No other covariate was found to reach significance in predicting RH across the eleven studies. Only four studies reported LOS as an outcome (23, 24, 30, 31). Of these, Gjoertz et al. (30) and Staab et al. (24) were the only studies to reach significance, reporting mean LOS reductions of 34 and 21 days for EDCs on HCR compared with LCR, respectively (p < .001). Haynos et al. (23) and Matthews et al. (31) reported higher adherence to treatment under standardised HCR protocols than under individually tailored HCR plans (reported metrics detailed in Table 1). Two studies compared LCR and HCR protocols (24, 31), whereas the remaining studies focused only on an HCR protocol. No standard definition of “LCR” or “HCR” was shared across studies. Matthews et al. (31) compared initiating 1,000 kcal/d (LCR) versus 1,500 kcal/d (HCR), whereas Staab et al. (24) compared initiating at 1,500–1,600 kcal/d versus 1,600–1,800 kcal/d. The highest initial caloric intake prescribed via a standardised approach was 2,000 kcal/d (22, 25, 29), with the upper reported goal of 7,000 kcal/d (30), and the other goals ranged from 2,500–4,000 kcal/d. One study did not include a fixed feeding protocol, providing a range and means of initial and discharge calorie intake on the basis of EDCs gaining ~2 kg/week (32). This study also stratified initial and discharge calories between male and female EDCs and reported no significant sex differences in weight gain per week (32). Most papers (90%) reported on at least one secondary outcome (rate of weight gain, changes in admission and discharge BMI), with only one study focusing instead on comparing HCR treatment between a medical centre and community hospital rather than differences in these parameters (28). Of the nine studies that reported weight gain, five reported higher mean weekly gains under HCR (0.7–2.1 kg/week). One study reported no significant difference in weight gain within the first week (31). Five studies reported no difference in the weight gain rate between minors and adults (22, 27-30). The quasi-experimental study by Staab et al. (24) reported a shorter time to reach the target BMI under HCR than under LCR (median 59 vs. 81 days; p < .001) and a higher mean rate of weight gain by 0.21 kg/week under HCR. Discussion Across predominantly retrospective and quasi-experimental cohorts, observational evidence suggests that HCR is associated with faster in-hospital progress—a shorter length of stay and greater weekly weight gain—without a clearly increased rate of clinical RFS and with variably reported but generally manageable rates of RH. Taken together, the eleven studies suggest that, in supervised inpatient settings with electrolyte monitoring and supplementation protocols, initiating at ≥1,500–2,000 kcal/d and advancing progressively may offer operational advantages to hospital and health services compared with LCR. Notably, clinical RFS events were uncommon, and no deaths were reported; however, the follow-up time was short, and studies were not powered for rare safety outcomes. LCR protocols for EDCs have been recommended substantially, starting from ~1,200 kcal/d or lower and increasing slowly (23). This clinical paradigm of 'go low and slow' was rationalised to minimise the risk of RFS occurrence and limit preventable deaths. Claims that LCR “succeeds” because few RFS cases have been reported should be interpreted cautiously given historical under-detection and varied definitions (5, 7). However, the increasing prevalence of EDs in Australia and the resulting pressures on healthcare systems have given rise to the need to seek clinical practices that are both safe and efficient (4). Within these constraints, this scoping review signals that HCR can be delivered safely in specialist inpatient settings with protocolised monitoring; nevertheless, certainty is limited by nonrandomised designs, baseline imbalances, and measurement heterogeneity. While all studies reported on refeeding, many different outcomes to determine and define occurrence were reported between studies. Most studies have quantified biochemical RH (low serum phosphate), not clinical RFS, which aligns with previous studies (16). However, the manifestations of RFS remain nonunanimous and nonspecific, so the use of RH alone as a surrogate for RFS risks misclassification (5). Where examined, associations between RH and clinical RFS were inconsistent and generally underpowered; thus, no firm linkage can be made in these cohorts. Alternative and adjunctive markers such as oedema have been proposed but have been applied inconsistently (23, 25). Phosphate supplementation was reported by nine papers to varying degrees in terms of indication, dosage, and timing (22, 24, 25, 27-32), with only Staab et al. (24) reporting more frequent use of LCR than HCR (not statistically significant). High variations in reported RH likely reflect different electrolyte correction strategies and dosages, a well-documented finding in the adolescent EDC literature (10, 12). Standardising sampling windows (e.g., timing of first 72 h draws), RH thresholds (adult vs adolescent), and prophylactic versus reactive supplementation would improve comparability and enable data pooling in future studies. Across studies reporting RH, samples differed in disease severity, with Gibson et al. (32) reporting a mean admission BMI of 12.1 kg/m², whereas Kells et al. (27) reported a BMI of 16.3 kg/m². While Gibson et al. (32) included severe EDCs, they also had a higher RH cut-off than did the other included studies. Multiple studies reported an inverse association between lower admission BMI and RH risk, but the effect sizes and significance varied, and not all analyses were adjusted for confounders (29). No deaths occurred, and the reported clinical RFS severity was minimal, albeit with limited follow-up and inpatient-bound outcomes. Unlike adolescent EDC studies, adult cohort studies lack higher-quality prospective or randomised studies with longer follow-up periods (11). The LOS appeared to be shorter in some HCR cohorts, including severe EDC admissions (24), which is consistent with paediatric- and adolescent-focused studies (9). Unfortunately, significant variations in the length of admissions and follow-up times between the included studies and baseline case-mix differences make generalisations difficult. Additionally, severe EDC admissions may require more prolonged hospital admissions due to medical complications irrespective of RFS risk or occurrence, introducing confounding by indications (34). Limitations and strengths of the study The strengths of this review were that the studies included severely malnourished EDCs across adolescent, young adult and adult populations (24, 25, 29, 32), defined by the inclusion of participants with a BMI < 15 kg/m² (1). Furthermore, no consistent association between higher starting caloric intake and increased clinical RFS was observed across studies, despite large variations. This result aligns with the findings of previous adolescent studies on EDC, which reported that HCR can be delivered safely in patients with mild to moderate disease severity (10, 11). While the quality of studies was not rigorously tested as part of this scoping review, most evidence from the included studies was derived from retrospective or observational studies. These types of studies are subject to biases, such as selection bias. Confounding by indication/era (e.g., lower admission BMI, centre protocols, and admission pathways), measurement heterogeneity (RH/RFS definitions and sampling schedules), and incomplete reporting of intervention fidelity (starting-calorie adherence and advancement) are likely to influence the observed effects. Selection bias may have occurred because patients perceived as high-risk RFS were assigned to an initially lower calorie prescription where standardised approaches were not used. Electrolyte supplementation (indication/dose/time) may also confound the incidence of RH. Evidence gaps and future research directions: Compared with the LCR, the HCR may decrease the LOS in EDC consumer presentation to adult medical services, particularly those with severe AN (admission BMI <15 kg/m²) in tertiary hospital settings. This potential benefit should be confirmed in prospective designs and interpreted alongside resource- and patient-centred outcomes. Given that the current RFS criteria place substantial weight on low BMI, future work should examine whether multivariable risk tools outperform single-threshold approaches for predicting clinically meaningful RFS. There is no universal definition of RFS, with significant variations in criterion markers between studies, making data synthesis difficult. Consensus-building efforts among researchers, clinicians, and policymakers are needed to standardise RFS criteria and RH thresholds across both adult and young adult services that are age- and developmentally inclusive. Future studies should explore the role of electrolyte supplementation, particularly in severe EDC presentations where the admission BMI is <15 kg/m². Owing to heterogeneity and the fact that some studies have not reported on its occurrence, it is unclear to what degree this may influence the risk of RFS and occurrence, as well as the different approaches to supplementation (i.e., prophylactic versus reactive). Prospective protocols should preregister supplementation triggers, dosing, and monitoring to reduce performance and detection bias. While no deaths were reported in any of the included studies, there was minimal follow-up time in the included studies. Longer-term follow-up is needed to assess morbidity, readmission, and functional outcomes and to evaluate any risks potentially associated with accelerated weight gain targets (e.g., > 2 kg/week). Conclusion This scoping review has synthesised and summarised evidence regarding the clinical practice of HCR in EDCs within an adult hospital setting. With respect to safety, current observational evidence indicates that HCR can be implemented without a clear increase in clinical RFS in adult EDCs compared with the usual practice of LCR. However, the generalisability of the results is limited due to considerable heterogeneity in how the RFS is defined and measured. While HCR approaches are beginning to be adopted in paediatric and adolescent EDC settings, few high-quality studies, such as RCTs, currently exist in adult EDCs, with no such studies identified and included in this review. The quality of the included studies was limited because the majority were retrospective or observational in design. Accordingly, stronger prospective evidence with standardised RH/RFS definitions, electrolyte protocols, and adherence reporting is needed to inform practice and policy. Furthermore, future studies involving longer follow-up periods would be beneficial to determine if there are any other covariates in adult EDCs who receive HCR in response to accelerated weight gain targets and potentially decreased LOS. Declarations Ethics approval and consent to participate: Not applicable Consent for publication: Not applicable Availability of data and materials: All the data generated or analysed during this study are included in this published article and its supplementary information files. [Insert Supplementary 1: Database search strategy.] [Insert Supplementary 2: Inclusion and exclusion criteria (Population, Issue, Outcomes) ] Competing interests: The authors declare that they have no competing interests. Funding: This work was supported by clinical backfill funding from Allied Health Research, Gold Coast Hospital and Health Service, in 2025. Authors’ contributions: J.T. conceptualised and performed the search strategy, screening, study selection, data analysis and wrote the main manuscript text. C.R. and M.S. performed screening, study selection and data analysis of the included full-text articles. G.B. provided research methodological support and contributed to the writing of the manuscript. All authors reviewed the manuscript. Acknowledgements: Not applicable Author Information: JT, MS, and CR are senior dietitians at Gold Coast Hospital and Health Services who provide nutrition care and recommendations, such as medical and mental health inpatient settings, adolescent and young adult day programs and adult community mental health services, to eating disorder consumers across the lifespan and continuum of care. GB (PhD) is a research and service development officer at Gold Coast Hospital and Health Services, with a background in occupational therapy. Footnotes: * Significance (p <.001); # Significance (p <.05); + Spearman correlation (r = 0.41) References American Psychiatric Association ib. Diagnostic and statistical manual of mental disorders: DSM-5-TR. Fifth edition, text revision. ed. Washington, DC: American Psychiatric Association Publishing; 2022. Auger N, Potter BJ, Ukah UV, Low N, Israël M, Steiger H, et al. Anorexia nervosa and the long-term risk of mortality in women. 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Kells M, Gregas M, Wolfe BE, Garber AK, Kelly-Weeder S. Factors associated with refeeding hypophosphatemia in adolescents and young adults hospitalized with anorexia nervosa. Nutr Clin Pract. 2022;37(2):470–8. Strandjord SE, Sieke EH, Richmond M, Khadilkar A, Rome ES. Medical stabilization of adolescents with nutritional insufficiency: a clinical care path. Eat weight disorders. 2016;21(3):403–10. Cuntz U, Körner T, Voderholzer U. Rapid renutrition improves health status in severely malnourished inpatients with AN - score‐based evaluation of a high caloric refeeding protocol in severely malnourished inpatients with anorexia nervosa in an intermediate care unit. Eur Eat disorders Rev. 2022;30(2):178–89. Gjoertz M, Wang J, Chatelet S, Monney Chaubert C, Lier F, Ambresin AE. Nutrition Approach for Inpatients With Anorexia Nervosa: Impact of a Clinical Refeeding Guideline. JPEN J Parenter Enter Nutr. 2020;44(6):1124–39. Matthews K, Hill J, Jeffrey S, Patterson S, Davis A, Ward W, et al. A Higher-Calorie Refeeding Protocol Does Not Increase Adverse Outcomes in Adult Patients with Eating Disorders. J Acad Nutr Dietetics. 2018;118(8):1450–63. Gibson D, Watters A, Cost J, Mascolo M, Mehler PS. Extreme anorexia nervosa: medical findings, outcomes, and inferences from a retrospective cohort. J Eat disorders. 2020;8(1):25–10. Rio A, Whelan K, Goff L, Reidlinger DP, Smeeton N. Occurrence of refeeding syndrome in adults started on artificial nutrition support: prospective cohort study. BMJ open. 2013;3(1):e002173. Garber AK, Cheng J, Accurso EC, Adams SH, Buckelew SM, Kapphahn CJ, et al. Short-term Outcomes of the Study of Refeeding to Optimize Inpatient Gains for Patients With Anorexia Nervosa: A Multicenter Randomized Clinical Trial. JAMA Pediatr. 2021;175(1):19–27. Tables Table 1 is available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Table1Results.docx Table 1: Key methodological features and quantitative findings from included studies (N = 11) Abbreviations: AN = anorexia nervosa, BMI = body mass index, ED = eating disorder, HCR = high calorie refeeding, K = potassium, LCR = low calorie refeeding, LOS = length of stay, Mg = magnesium, PO4 = phosphate, RFS = refeeding syndrome, RH = refeeding hypophosphataemia, SD = standard deviation, Wt = weight Supplementary1searchstrategy.docx Supplementary 1: Database search strategy. Supplementary2InclusionexclusioncriteriaPIO.docx Supplementary 2: Inclusion and exclusion criteria (Population, Issue, Outcomes) Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 22 Apr, 2026 Reviews received at journal 20 Apr, 2026 Reviews received at journal 20 Apr, 2026 Reviews received at journal 07 Apr, 2026 Reviewers agreed at journal 31 Mar, 2026 Reviewers agreed at journal 31 Mar, 2026 Reviewers agreed at journal 30 Mar, 2026 Reviewers agreed at journal 28 Mar, 2026 Reviews received at journal 02 Mar, 2026 Reviewers agreed at journal 21 Jan, 2026 Reviewers agreed at journal 21 Jan, 2026 Reviewers invited by journal 21 Jan, 2026 Editor assigned by journal 19 Jan, 2026 Submission checks completed at journal 19 Jan, 2026 First submitted to journal 07 Jan, 2026 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. 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1","display":"","copyAsset":false,"role":"figure","size":60467,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ePRISMA table on new methodology\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePRISMA study flow diagram showing the study selection process.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8537410/v1/cc063f684c89d62d68633b11.png"},{"id":100954103,"identity":"619ca2c9-b719-4d1c-98cf-e4048b98026f","added_by":"auto","created_at":"2026-01-23 07:23:45","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":818341,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8537410/v1/a36cbbb5-8152-4426-b19a-c6f75284715c.pdf"},{"id":100951341,"identity":"d38ad278-003e-42a7-a104-fac8275dee78","added_by":"auto","created_at":"2026-01-23 07:10:31","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":75492,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eTable 1: Key methodological features and quantitative findings from included studies (N = 11)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAbbreviations: AN = anorexia nervosa, BMI = body mass index, ED = eating disorder, HCR = high calorie refeeding, K = potassium, LCR = low calorie refeeding, LOS = length of stay, Mg = magnesium, PO4 = phosphate, RFS = refeeding syndrome, RH = refeeding hypophosphataemia, SD = standard deviation, Wt = weight\u003c/p\u003e","description":"","filename":"Table1Results.docx","url":"https://assets-eu.researchsquare.com/files/rs-8537410/v1/b9f6f2bdc8b2a6e838fbdfef.docx"},{"id":100930279,"identity":"e392b25c-497c-438c-9ebd-9803aa3a6e99","added_by":"auto","created_at":"2026-01-23 00:40:29","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":27401,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSupplementary 1: Database search strategy.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Supplementary1searchstrategy.docx","url":"https://assets-eu.researchsquare.com/files/rs-8537410/v1/decaad4385db65a3e11fbda8.docx"},{"id":100951610,"identity":"05a7cb1c-6f0e-4fb9-be84-96c333ab6fcf","added_by":"auto","created_at":"2026-01-23 07:10:58","extension":"docx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":24606,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSupplementary 2:\u0026nbsp;Inclusion and exclusion criteria (Population, Issue, Outcomes)\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Supplementary2InclusionexclusioncriteriaPIO.docx","url":"https://assets-eu.researchsquare.com/files/rs-8537410/v1/f6938c228c64eeb1d12f5af3.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Can higher-calorie feeding protocols for patients with eating disorders admitted to an adult hospital ward be safely implemented to reduce the length of stay? A scoping review","fulltext":[{"header":"Plain English Summary","content":"\u003cp\u003ePeople admitted to the hospital for an eating disorder often need careful \u0026ldquo;refeeding\u0026rdquo; to restore nutrition. Many services still start with low-calorie feeding and increase slowly to avoid a rare but serious complication called refeeding syndrome (dangerous shifts in body electrolytes and fluids). However, newer studies\u0026mdash;mostly in younger patients\u0026mdash;have suggested that starting with more calories, alongside close blood test monitoring and vitamin/mineral supplements, may be just as safe and could help people recover faster and leave the hospital sooner.\u003c/p\u003e\n\u003cp\u003eThis scoping review maps what is known about higher- versus lower-calorie refeeding in adult hospital wards. We will compare safety (refeeding syndrome and low blood phosphate), length of stay, and weight or body mass index changes. Because studies use different definitions and monitoring routines, we will record exactly how each study measured these outcomes so that the findings can be compared fairly. The results can help clinicians, patients, and services obtain a clear overview of the evidence to support safe, timely, and effective inpatient nutritional care.\u003c/p\u003e"},{"header":"Background","content":"\u003cp\u003eEating disorders (EDs) are severe psychiatric illnesses marked by persistent disturbances in eating behaviours and body image, often driven by weight and shape concerns (1). Diagnoses include anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED), and avoidant/restrictive food intake disorder (ARFID). EDs cause profound psychological distress and medical morbidity, with AN resulting in the highest mortality of any psychiatric disorder, most often due to suicide or complications of prolonged malnutrition (2).\u003c/p\u003e\n\u003cp\u003eIn Australia, up to 16% of adults will experience an ED in their lifetime (3). Hospital admissions for EDs increased by 91% between 2008 and 2018, with an average length of stay (LOS) of 21 days (4). Many patients are admitted following prolonged starvation and are considered at risk of refeeding syndrome (RFS), a potentially life-threatening cluster of electrolyte and fluid disturbances triggered by nutritional rehabilitation (5). Concern about RFS has historically led services to adopt conservative \u0026ldquo;low and slow\u0026rdquo; refeeding protocols in the first 24\u0026ndash;48 hours of admission.\u003c/p\u003e\n\u003cp\u003eRFS was first described in the Minnesota Starvation Experiment, which documented metabolic changes during the refeeding of semi-starved men (6). Although influential, the study has ethical and methodological limitations and offers little guidance for contemporary ED care. International guidelines such as the National Institute for Health and Care Excellence (NICE) (7) define generic risk criteria, but these lack specificity for ED populations. More recent consensus statements, including the 2025 Australasian Society for Parenteral and Enteral Nutrition (AuSPEN) guidance, recommend against the routine use of \u0026ldquo;start low, go slow\u0026rdquo; approaches and instead advocate progression to full nutritional requirements within the first 24\u0026ndash;72 hours, supported by structured monitoring and prophylactic supplementation (8). Conservative low-calorie refeeding (LCR) aims to prevent RFS but may prolong catabolism, limit early weight gain, and extend LOS, potentially exacerbating bradycardia, hypotension, and fatigue that delay therapy engagement (9). In contrast, higher-calorie refeeding (HCR) protocols, when combined with careful monitoring, appear equally safe and more effective (10). In adolescents, a multicentre randomised trial revealed no difference in RFS, readmission, or mortality between HCR and LCR, but HCR achieved faster weight restoration (11). Systematic reviews in paediatric and young adult cohorts similarly reported a reduced LOS and no excess mortality with HCR, irrespective of disease severity (12).\u003c/p\u003e\n\u003cp\u003eBy comparison, the adult evidence base is sparse. Australian clinical practice guidelines currently recommend a cautious \u0026ldquo;middle path\u0026rdquo; initiation of ~1400 kcal/day, reflecting uncertainty about how to balance RFS risk against the harms of underfeeding (13). Emerging adult studies suggest that increased starting prescriptions may be safe in those with mild to severe malnutrition (14). A recent prospective observational study of adults admitted to medical and psychiatric wards revealed that the HCR was not associated with increased clinical RFS and appeared to support a shorter LOS and greater weight restoration, but outcome reporting and protocol details varied (15). Across adult studies, definitions of RFS, thresholds for biochemical abnormalities (e.g., hypophosphataemia), and measures of weight gain or body mass index (BMI) change are inconsistent, limiting synthesis and clinical translation (16).\u003c/p\u003e\n\u003cp\u003eAnother key consideration is that many late adolescents and young adults with EDs transition from child and youth services to adult hospital wards during a period of changing legal status and autonomy. Treatment models and expectations often differ across these settings, and disengagement rates are high (17). Because these individuals are frequently managed within adult inpatient units and subject to adult refeeding protocols, understanding the safety and outcomes of HCR in these environments is essential to ensure that continuity of care can be provided across paediatric and adult service lines to support this transitional phase (18).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAims of the review\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis scoping review was designed to address the lack of clear, adult-focused evidence comparing high-calorie refeeding (HCR) and low-calorie refeeding (LCR) in inpatient eating disorder care. Adult studies remain heterogeneous, with inconsistent definitions of refeeding syndrome (RFS), variable reporting of length of stay (LOS), and non-standardised measures of weight gain and BMI change. These uncertainties limit clinical decision-making and highlight the need for systematic evidence mapping before formal effectiveness trials can be undertaken.\u003c/p\u003e\n\u003cp\u003eAccordingly, this review aims to explore the existing evidence regarding HCR versus LCR protocols in adult hospital wards treating people with eating disorders, including late adolescents and young adults admitted to adult services. Specifically, it seeks to answer the following research questions:\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003eWhat is the existing evidence on the occurrence of RFS when initiating HCR compared with LCR for eating disorder consumers admitted to adult hospital wards?\u003c/li\u003e\n \u003cli\u003eDoes initiating HCR protocols, unlike LCR protocols, for eating disorder consumers in an adult inpatient ward influence the length of stay?\u003c/li\u003e\n \u003cli\u003eDoes initiating HCR protocols rather than LCR protocols for eating disorder consumers in an adult inpatient ward influence the rate of weight gain or BMI changes during admission?\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eProtocol and registration:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis scoping review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines from the latest Joanna Briggs Institute (JBI) guidance for scoping review (19).\u003c/p\u003e\n\u003ch2\u003eSearch strategy:\u003c/h2\u003e\n\u003cp\u003eThe MEDLINE, CINAHL, American Psychological Association (APA) PsycArticles, ProQuest and Scopus electronic databases were used to conduct systematic literature searches.\u003c/p\u003e\n\u003cp\u003eThe search strategy, including the databases, key search terms, and number of articles identified via this method, is shown in Supplementary 1. The search was undertaken during July 2025 and was limited to articles published between 1 Jan 2012 and 30 June 2025, as high-calorie refeeding remains a relatively novel approach. Potential additional studies were identified through snowballing; the reference lists of relevant systematic reviews, narrative reviews and meta-analyses identified in the \u0026ldquo;title/abstract\u0026rdquo; screening were searched in addition to the reference list of the QuEDs guidelines.\u003c/p\u003e\n\u003ch2\u003eSelection criteria:\u003c/h2\u003e\n\u003cp\u003eEligibility criteria\u003c/p\u003e\n\u003cp\u003eEligibility was based on the PIO criteria: population, issues and outcomes to structure the question and guide. Papers that met the following criteria were included:\u003c/p\u003e\n\u003col style=\"list-style-type: lower-alpha;\"\u003e\n \u003cli\u003ePatients previously had a diagnosis of an eating disorder [anorexia nervosa, bulimia nervosa, binge eating disorder, avoidant and restrictive food intake disorder (ARFID)].\u003c/li\u003e\n \u003cli\u003ePatients were admitted to an adult inpatient unit (e.g., general medical, psychiatric, or specialist inpatient unit for eating disorder treatment).\u003c/li\u003e\n \u003cli\u003e\u0026nbsp;HCRs \u0026ge;1500 calories/day were initially received as part of the nutrition intervention\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u003cstrong\u003ePopulation:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStudies including individuals of any age or sex who received HCR due to an eating disorder with a diagnosis of AN, BN, EDNOS, OSFED, or ARFID within an adult hospital setting requiring nutritional restoration. Studies were excluded if they were conducted in a paediatric unit or a young adult unit that excluded adult Eating Disorder Consumers (EDCs) on the basis of age (e.g., not providing care to those \u0026gt; 18 years of age).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIssue:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHigher caloric refeeding (HCR) rates of \u0026ge;1500 calories/day are needed for eating disorder patients admitted to an inpatient adult ward.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOutcomes:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStudies were eligible if they mentioned at least one primary measure related to refeeding syndrome markers during hospital admission. Examples of such markers included hypophosphataemia, hypokalaemia, hypomagnesaemia, peripheral oedema or a combination of these. The secondary outcomes of interest, including length of stay, rate of weight gain and changes in admission and discharge body mass indices (BMIs), were also reported, although these were not necessary inclusion criteria.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy design:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe studies included were randomised controlled trials, case‒controlled studies, and observational and cohort studies. Case studies, qualitative studies, abstracts of poster presentations, theses and gray\u0026nbsp;literature were excluded.\u003c/p\u003e\n\u003ch3\u003eScreening process\u003c/h3\u003e\n\u003cp\u003eTitle and abstract screening of all records was performed by three reviewers (JT, CR, MS), with one author as the first rater (JT) and the second rater shared between the other two authors (MS, CR) via web-based systematic review software (Covidence). Raters independently assessed the eligibility of the articles that were identified following the database search based on the eligibility criteria.\u0026nbsp;Duplicates were removed from Covidence and manually checked. Records that appeared to meet the inclusion criteria on the basis of title and abstract were retrieved for full-text review. Full-text screening was again performed independently by the same three reviewers, with discrepancies resolved through discussion and, where needed, majority consensus.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eStudy selection:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData were extracted into an Excel spreadsheet created for review by all three authors who completed full-text screening, following an established framework for scoping reviews (20). The data extracted included the region of the study, type of study design, age of the participants with an eating disorder, refeeding protocol and incidence of refeeding syndrome. Each of the reviewers independently recorded the data, discussed the results and continuously updated the data-charting form in an iterative process. The data obtained from the included studies were confirmed on a majority basis. If no majority was reached, all three reviewers analysed the included papers together to reach a consensus. The main revisions through this process were charting if prophylactic supplementation was mentioned in the study protocol, as this may have influenced how HCR was conducted.\u003c/p\u003e"},{"header":"Results","content":"\u003ch2\u003eStudy Selection\u003c/h2\u003e\n\u003cp\u003eThe systematic database search yielded 778 articles. Once duplicates (n = 275 articles) were removed, the abstracts and titles of 503 articles were screened for inclusion in this review. Most of the articles (n = 456) were excluded because of irrelevancy. The remaining 47 full-text articles were screened for inclusion in this review. A further 36 articles were excluded for predefined reasons such as paediatric-only settings (n=14) and incorrect interventions, such as initiating an LCR (n=7). One article identified via citation chaining (Matthews et al., 2018) was included, resulting in a total of eleven included papers. Figure 1 shows the modified PRISMA flow diagram in which the search yields are presented (21).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFigure 1:\u0026nbsp;\u003c/strong\u003ePRISMA study flow diagram showing the study selection process.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e[Insert Figure 1 PRISMA table on new methodology]\u003c/strong\u003e\u003c/p\u003e\n\u003ch2\u003eSummary of outcomes\u003c/h2\u003e\n\u003cp\u003eTable 1 summarises the findings of the eleven included studies, which were conducted in the United States, Germany, Australia, Canada and Switzerland. Most papers that met the inclusion criteria were observational and retrospective cohort studies, with three studies employing a quasi-experimental (before-after/natural-experiment) design (22-24). The mean ages across the included studies demonstrated substantial variation depending on the population sampled but clustered around the middle-to-late twenties for adult cohorts. The mean age ranged from 23.8 years (25) to 32.5 years (26) for studies focused on adult eating disorder consumers. Conversely, studies including paediatric and adolescent samples reported lower mean ages, such as 15.5 years (27), 17.3 years (22), and a median of 17 years (28). Six of the eleven studies sampled only consumers with an anorexia nervosa (AN) diagnosis (22-25, 27, 29). Eight studies were conducted in a specialised inpatient ward and setting for eating disorder consumers, whereas three papers were conducted in a general hospital inpatient setting (28, 30, 31).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1:\u003c/strong\u003e Key methodological features and quantitative findings from the included studies (N = 11)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e[Insert Table 1: Key methodological features and quantitative findings from included studies (N = 11)]\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAbbreviations: AN = anorexia nervosa,\u0026nbsp;BMI = body mass index,\u0026nbsp;ED =\u0026nbsp;eating disorder,\u0026nbsp;HCR = high calorie refeeding,\u0026nbsp;K = potassium,\u0026nbsp;LCR = low calorie refeeding,\u0026nbsp;LOS = length of stay,\u0026nbsp;Mg = magnesium, PO4 = phosphate, RFS = refeeding syndrome, RH = refeeding\u0026nbsp;hypophosphataemia,\u0026nbsp;SD = standard deviation,\u0026nbsp;Wt\u0026nbsp;= weight\u003c/p\u003e\n\u003cp\u003eThe exclusion criteria varied across study designs by diagnosis, duration of hospitalisation, weight status, and concurrent medical conditions. Five papers focused solely on AN by excluding other eating-disorder diagnoses (22, 24, 25, 27, 30), whereas three included broader diagnoses (26, 28, 31). Length-of-stay (LOS)/retention-period exclusions are common: \u0026lt;24 h (28), \u0026lt;72 h (32), \u0026lt;5 days (31), and \u0026lt;7 days (23, 24, 30). Two cohorts required LOS \u0026ge;28 days (25, 29), and others reported no explicit LOS-related exclusion (22, 26, 27). Additional exclusions included pregnancy and non-ED medical comorbidities (23, 31). In all included studies, the number of female participants was proportionally greater than that of male participants, and Koerner et al. (25) reported that no males met the BMI \u0026lt;13 kg/m\u0026sup2; inclusion threshold.\u003c/p\u003e\n\u003cp\u003eWeight-status criteria across the eleven studies varied by metric (BMI vs. %IBW/%mBMI) and function (inclusion vs. exclusion). An explicit exclusion ceiling was used in Gibson et al. (32) (\u0026gt;65% IBW excluded), and a severe-underweight entry threshold was used in Koerner et al. (25) (BMI \u0026lt;13 kg/m\u0026sup2;). Youth/mixed-age cohorts operationalise severity using the %mBMI (22, 26, 27, 30), whereas several adult or mixed cohorts report no explicit weight-based exclusion and rely on clinical admission pathways (23, 24, 29, 31). Where specified, some cohorts described very low BMI inclusion bands (e.g., \u0026lt;15 kg/m\u0026sup2;) to characterise baseline severity.\u003c/p\u003e\n\u003cp\u003eThe observational study by Cuntz et al. (29) was the largest, with 3230 admissions in a 15-bed specialised inpatient ward for EDCs across four years. The smallest study included was that of Haynos et al. (23), which initially involved 70 EDCs in their quasi-experimental design and a subsample of 20 for secondary analysis of RFS occurrence. Across the eleven included studies, a total of 4,874 patients were analysed for the incidence of RFS.\u003c/p\u003e\n\u003ch2\u003eStudy findings\u003c/h2\u003e\n\u003cp\u003e\u0026nbsp;All eleven studies reported on hypophosphataemia, with eight papers measuring refeeding hypophosphataemia (RH), while one measured the incidence of refeeding in the presence of oedema only (23). Among the eight studies reporting on RH, there was heterogeneity between the definitions and severity thresholds (i.e., mild, critical). The cut-off for RH ranged from 0.75 mmol--0.91 mmol/L, whereas the critical RH ranged from 0.31--0.71 mmol/L.\u003c/p\u003e\n\u003cp\u003eTwo studies included in this analysis utilised the same cut-offs to establish their own criteria for refeeding syndrome occurrence (25, 29), while two studies defined it on the basis of the criteria of Rio et al. (33) (22, 24), and four studies cited criteria on the basis of the NICE guidelines (7, 26, 28, 30, 31). The other two studies with a lower mean age defined hypophosphataemia as \u0026lt;0.9 mmol/L in alignment with adolescent guidelines (27, 32).\u0026nbsp;Only two of the eleven studies reported cases of RH\u0026nbsp;(27, 32), with Gibson et al.\u0026nbsp;(32)\u0026nbsp;reporting that it occurred in 35% of their sample (5 males and 93 females), with 47% of these patients (3 males and 43 females) meeting their criteria for critical hypophosphataemia. There were no deaths or cases of refeeding syndrome reported in any of the included studies. When accounting for BMI, four papers reported that a lower admission BMI was significantly (p \u0026lt;.001) associated with an increased risk in predicting RH\u0026nbsp;(23, 26, 32), with Cuntz et al.\u0026nbsp;(29)\u0026nbsp;reporting a highly significant and negative correlation (Spearman correlation 0.41, p \u0026lt;.000) between the two variables. No other covariate was found to reach significance in predicting RH across the eleven studies.\u003c/p\u003e\n\u003cp\u003eOnly four studies reported LOS as an outcome (23, 24, 30, 31). Of these, Gjoertz et al. (30) and Staab et al. (24) were the only studies to reach significance, reporting mean LOS reductions of 34 and 21 days for EDCs on HCR compared with LCR, respectively (p \u0026lt; .001). Haynos et al. (23) and Matthews et al. (31) reported higher adherence to treatment under standardised HCR protocols than under individually tailored HCR plans (reported metrics detailed in Table 1).\u003c/p\u003e\n\u003cp\u003eTwo studies compared LCR and HCR protocols (24, 31), whereas the remaining studies focused only on an HCR protocol. No standard definition of \u0026ldquo;LCR\u0026rdquo; or \u0026ldquo;HCR\u0026rdquo; was shared across studies. Matthews et al. (31) compared initiating 1,000 kcal/d (LCR) versus 1,500 kcal/d (HCR), whereas Staab et al. (24) compared initiating at 1,500\u0026ndash;1,600 kcal/d versus 1,600\u0026ndash;1,800 kcal/d. The highest initial caloric intake prescribed via a standardised approach was 2,000 kcal/d (22, 25, 29), with the upper reported goal of 7,000 kcal/d (30), and the other goals ranged from 2,500\u0026ndash;4,000 kcal/d. One study did not include a fixed feeding protocol, providing a range and means of initial and discharge calorie intake on the basis of EDCs gaining ~2 kg/week (32). This study also stratified initial and discharge calories between male and female EDCs and reported no significant sex differences in weight gain per week (32).\u003c/p\u003e\n\u003cp\u003eMost papers (90%) reported on at least one secondary outcome (rate of weight gain, changes in admission and discharge BMI), with only one study focusing instead on comparing HCR treatment between a medical centre and community hospital rather than differences in these parameters (28). Of the nine studies that reported weight gain, five reported higher mean weekly gains under HCR (0.7\u0026ndash;2.1 kg/week). One study reported no significant difference in weight gain within the first week (31). Five studies reported no difference in the weight gain rate between minors and adults (22, 27-30). The quasi-experimental study by Staab et al. (24) reported a shorter time to reach the target BMI under HCR than under LCR (median 59 vs. 81 days; p \u0026lt; .001) and a higher mean rate of weight gain by 0.21 kg/week under HCR.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eAcross predominantly retrospective and quasi-experimental cohorts, observational evidence suggests that HCR is associated with faster in-hospital progress\u0026mdash;a shorter length of stay and greater weekly weight gain\u0026mdash;without a clearly increased rate of clinical RFS and with variably reported but generally manageable rates of RH. Taken together, the eleven studies suggest that, in supervised inpatient settings with electrolyte monitoring and supplementation protocols, initiating at \u0026ge;1,500\u0026ndash;2,000 kcal/d and advancing progressively may offer operational advantages to hospital and health services compared with LCR. Notably, clinical RFS events were uncommon, and no deaths were reported; however, the follow-up time was short, and studies were not powered for rare safety outcomes.\u003c/p\u003e\n\u003cp\u003eLCR protocols for EDCs have been recommended substantially, starting from ~1,200 kcal/d or lower and increasing slowly (23). This clinical paradigm of \u0026apos;go low and slow\u0026apos; was rationalised to minimise the risk of RFS occurrence and limit preventable deaths. Claims that LCR \u0026ldquo;succeeds\u0026rdquo; because few RFS cases have been reported should be interpreted cautiously given historical under-detection and varied definitions (5, 7). However, the increasing prevalence of EDs in Australia and the resulting pressures on healthcare systems have given rise to the need to seek clinical practices that are both safe and efficient (4). Within these constraints, this scoping review signals that HCR can be delivered safely in specialist inpatient settings with protocolised monitoring; nevertheless, certainty is limited by nonrandomised designs, baseline imbalances, and measurement heterogeneity.\u003c/p\u003e\n\u003cp\u003eWhile all studies reported on refeeding, many different outcomes to determine and define occurrence were reported between studies. Most studies have quantified biochemical RH (low serum phosphate), not clinical RFS, which aligns with previous studies (16). However, the manifestations of RFS remain nonunanimous and nonspecific, so the use of RH alone as a surrogate for RFS risks misclassification (5). Where examined, associations between RH and clinical RFS were inconsistent and generally underpowered; thus, no firm linkage can be made in these cohorts. Alternative and adjunctive markers such as oedema have been proposed but have been applied inconsistently (23, 25).\u003c/p\u003e\n\u003cp\u003ePhosphate supplementation was reported by nine papers to varying degrees in terms of indication, dosage, and timing (22, 24, 25, 27-32), with only Staab et al. (24) reporting more frequent use of LCR than HCR (not statistically significant). High variations in reported RH likely reflect different electrolyte correction strategies and dosages, a well-documented finding in the adolescent EDC literature (10, 12). Standardising sampling windows (e.g., timing of first 72 h draws), RH thresholds (adult vs adolescent), and prophylactic versus reactive supplementation would improve comparability and enable data pooling in future studies.\u003c/p\u003e\n\u003cp\u003eAcross studies reporting RH, samples differed in disease severity, with Gibson et al. (32) reporting a mean admission BMI of 12.1 kg/m\u0026sup2;, whereas Kells et al. (27) reported a BMI of 16.3 kg/m\u0026sup2;. While Gibson et al. (32) included severe EDCs, they also had a higher RH cut-off than did the other included studies. Multiple studies reported an inverse association between lower admission BMI and RH risk, but the effect sizes and significance varied, and not all analyses were adjusted for confounders (29). No deaths occurred, and the reported clinical RFS severity was minimal, albeit with limited follow-up and inpatient-bound outcomes. Unlike adolescent EDC studies, adult cohort studies lack higher-quality prospective or randomised studies with longer follow-up periods (11).\u003c/p\u003e\n\u003cp\u003eThe LOS appeared to be shorter in some HCR cohorts, including severe EDC admissions (24), which is consistent with paediatric- and adolescent-focused studies (9). Unfortunately, significant variations in the length of admissions and follow-up times between the included studies and baseline case-mix differences make generalisations difficult. Additionally, severe EDC admissions may require more prolonged hospital admissions due to medical complications irrespective of RFS risk or occurrence, introducing confounding by indications (34).\u003c/p\u003e\n\u003ch2\u003eLimitations and strengths of the study\u003c/h2\u003e\n\u003cp\u003eThe strengths of this review were that the studies included severely malnourished EDCs across adolescent, young adult and adult populations (24, 25, 29, 32), defined by the inclusion of participants with a BMI \u0026lt; 15 kg/m\u0026sup2; (1). Furthermore, no consistent association between higher starting caloric intake and increased clinical RFS was observed across studies, despite large variations. This result aligns with the findings of previous adolescent studies on EDC, which reported that HCR can be delivered safely in patients with mild to moderate disease severity (10, 11).\u003c/p\u003e\n\u003cp\u003eWhile the quality of studies was not rigorously tested as part of this scoping review, most evidence from the included studies was derived from retrospective or observational studies. These types of studies are subject to biases, such as selection bias. Confounding by indication/era (e.g., lower admission BMI, centre protocols, and admission pathways), measurement heterogeneity (RH/RFS definitions and sampling schedules), and incomplete reporting of intervention fidelity (starting-calorie adherence and advancement) are likely to influence the observed effects. Selection bias may have occurred because patients perceived as high-risk RFS were assigned to an initially lower calorie prescription where standardised approaches were not used. Electrolyte supplementation (indication/dose/time) may also confound the incidence of RH.\u003c/p\u003e\n\u003ch2\u003eEvidence gaps and future research directions:\u003c/h2\u003e\n\u003cp\u003eCompared with the LCR, the\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eHCR may decrease the LOS in EDC consumer presentation to adult medical services, particularly those with severe AN (admission BMI \u0026lt;15 kg/m\u0026sup2;) in tertiary hospital settings. This potential benefit should be confirmed in prospective designs and interpreted alongside resource- and patient-centred outcomes. Given that the current RFS criteria place substantial weight on low BMI, future work should examine whether multivariable risk tools outperform single-threshold approaches for predicting clinically meaningful RFS.\u003c/p\u003e\n\u003cp\u003eThere is no universal definition of RFS, with significant variations in criterion markers between studies, making data synthesis difficult. Consensus-building efforts among researchers, clinicians, and policymakers are needed to standardise RFS criteria and RH thresholds across both adult and young adult services that are age- and developmentally inclusive.\u003c/p\u003e\n\u003cp\u003eFuture studies should explore the role of electrolyte supplementation, particularly in severe EDC presentations where the admission BMI is \u0026lt;15 kg/m\u0026sup2;. Owing to heterogeneity and the fact that some studies have not reported on its occurrence, it is unclear to what degree this may influence the risk of RFS and occurrence, as well as the different approaches to supplementation (i.e., prophylactic versus reactive). Prospective protocols should preregister supplementation triggers, dosing, and monitoring to reduce performance and detection bias.\u003c/p\u003e\n\u003cp\u003eWhile no deaths were reported in any of the included studies, there was minimal follow-up time in the included studies. Longer-term follow-up is needed to assess morbidity, readmission, and functional outcomes and to evaluate any risks potentially associated with accelerated weight gain targets (e.g., \u0026gt; 2 kg/week).\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis scoping review has synthesised and summarised evidence regarding the clinical practice of HCR in EDCs within an adult hospital setting. With respect to safety, current observational evidence indicates that HCR can be implemented without a clear increase in clinical RFS in adult EDCs compared with the usual practice of LCR. However, the generalisability of the results is limited due to considerable heterogeneity in how the RFS is defined and measured. While HCR approaches are beginning to be adopted in paediatric and adolescent EDC settings, few high-quality studies, such as RCTs, currently exist in adult EDCs, with no such studies identified and included in this review. The quality of the included studies was limited because the majority were retrospective or observational in design. Accordingly, stronger prospective evidence with standardised RH/RFS definitions, electrolyte protocols, and adherence reporting is needed to inform practice and policy. Furthermore, future studies involving longer follow-up periods would be beneficial to determine if there are any other covariates in adult EDCs who receive HCR in response to accelerated weight gain targets and potentially decreased LOS.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch3\u003eEthics approval and consent to participate:\u0026nbsp;Not applicable\u003c/h3\u003e\n\u003cp\u003eConsent for publication:\u0026nbsp;Not applicable\u003c/p\u003e\n\u003ch3\u003eAvailability of data and materials:\u003c/h3\u003e\n\u003cul\u003e\n \u003cli\u003eAll the data generated or analysed during this study are included in this published article and its supplementary information files.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003e[Insert Supplementary 1: Database search strategy.]\u0026nbsp;\u003c/strong\u003e\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003e[Insert Supplementary 2:\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;Inclusion and exclusion criteria (Population, Issue, Outcomes)\u003c/strong\u003e\u003cstrong\u003e]\u003c/strong\u003e\u003c/li\u003e\n\u003c/ul\u003e\n\u003ch3\u003eCompeting interests:\u003c/h3\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003ch3\u003eFunding:\u003c/h3\u003e\n\u003cp\u003eThis work was supported by clinical backfill funding from Allied Health Research, Gold Coast Hospital and Health Service, in 2025.\u003c/p\u003e\n\u003ch3\u003eAuthors\u0026rsquo; contributions:\u003c/h3\u003e\n\u003cp\u003eJ.T. conceptualised and performed the search strategy, screening, study selection, data analysis and wrote the main manuscript text.\u003c/p\u003e\n\u003cp\u003eC.R. and M.S. performed screening, study selection and data analysis of the included full-text articles.\u003c/p\u003e\n\u003cp\u003eG.B. provided research methodological support and contributed to the writing of the manuscript.\u003c/p\u003e\n\u003cp\u003eAll authors reviewed the manuscript.\u003c/p\u003e\n\u003ch3\u003eAcknowledgements:\u0026nbsp;Not applicable\u003c/h3\u003e\n\u003ch3\u003eAuthor Information:\u003c/h3\u003e\n\u003cp\u003eJT, MS, and CR are senior dietitians at Gold Coast Hospital and Health Services who provide nutrition care and recommendations, such as medical and mental health inpatient settings, adolescent and young adult day programs and adult community mental health services, to eating disorder consumers across the lifespan and continuum of care.\u003c/p\u003e\n\u003cp\u003eGB (PhD) is a research and service development officer at Gold Coast Hospital and Health Services, with a background in occupational therapy.\u003c/p\u003e\n\u003ch3\u003eFootnotes:\u003c/h3\u003e\n\u003cp\u003e\u003cem\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/em\u003e\u003cem\u003eSignificance (p \u0026lt;.001); \u003csup\u003e#\u003c/sup\u003eSignificance (p \u0026lt;.05); \u003csup\u003e+\u003c/sup\u003eSpearman correlation (r = 0.41)\u003c/em\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAmerican Psychiatric Association ib. 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The Australasian Society of Parenteral and Enteral Nutrition: Consensus statements on refeeding syndrome. Nutr dietetics. 2025;82(2):128\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eO\u0026rsquo;Connor G, Nicholls D. Refeeding Hypophosphatemia in Adolescents With Anorexia Nervosa: A Systematic Review. Nutr Clin Pract. 2013;28(3):358\u0026ndash;64.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGarber AK, Sawyer SM, Golden NH, Guarda AS, Katzman DK, Kohn MR, et al. A systematic review of approaches to refeeding in patients with anorexia nervosa. Int J Eat Disord. 2016;49(3):293\u0026ndash;310.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGolden NH, Cheng J, Kapphahn CJ, Buckelew SM, Machen VI, Kreiter A, et al. Higher-Calorie Refeeding in Anorexia Nervosa: 1-Year Outcomes From a Randomized Controlled Trial. Pediatr (Evanston). 2021;147(4):1.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMosuka EM, Murugan A, Thakral A, Ngomo MC, Budhiraja S. St. Victor R. Clinical Outcomes of Refeeding Syndrome: A Systematic Review of High vs. Low-Calorie Diets for the Treatment of Anorexia Nervosa and Related Eating Disorders in Children and Adolescents. Curēus (Palo Alto, CA). 2023;15(5):e39313.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHay P, Chinn D, Forbes D, Madden S, Newton R, Sugenor L, et al. Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for the treatment of eating disorders. Aust N Z J Psychiatry. 2014;48(11):977\u0026ndash;1008.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRedgrave GW, Coughlin JW, Schreyer CC, Martin LM, Leonpacher AK, Seide M, et al. Refeeding and weight restoration outcomes in anorexia nervosa: Challenging current guidelines. Int J Eat Disord. 2015;48(7):866\u0026ndash;73.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSalter F, Singh U, Kerr D, Zhao Y, Jeffery E. A prospective observational study examining weight and psychosocial change in adolescent and adult eating disorder inpatients admitted for nutritional rehabilitation using a high-energy re-feeding protocol. J Eat disorders. 2024;12(1):58\u0026ndash;14.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKraft MD, Btaiche IF, Sacks GS. Review of the Refeeding Syndrome. Nutr Clin Pract. 2005;20(6):625\u0026ndash;33.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRagnhildstveit A, Tuteja N, Seli P, Smart L, Uzun N, Bass LC, et al. Transitions from child and adolescent to adult mental health services for eating disorders: an in-depth systematic review and development of a transition framework. J Eat disorders. 2024;12(1):36\u0026ndash;17.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWade TD. A systematic review: Solutions to problems caused by age transition between eating disorder services. Eur Eat disorders Rev. 2023;31(2):247\u0026ndash;57.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePeters MDJ, Marnie C, Tricco AC, Pollock D, Munn Z, Alexander L, et al. Updated methodological guidance for the conduct of scoping reviews. JBI Evid Implement. 2021;19(1):3\u0026ndash;10.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eArksey H, O'Malley L. Scoping studies: towards a methodological framework. Int J Soc Res Methodol. 2005;8(1):19\u0026ndash;32.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePage MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDalenbrook S, Naab S, Garber A, Correll C, Voderholzer U, Haas V. Outcomes of a Standardized, High-Caloric, Inpatient Re-Alimentation Treatment Protocol in 120 Severely Malnourished Adolescents with Anorexia Nervosa. J Clin Med. 2022;11(9):2585.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHaynos AF, Snipes C, Guarda A, Mayer LE, Attia E. Comparison of standardized versus individualized caloric prescriptions in the nutritional rehabilitation of inpatients with anorexia nervosa. Int J Eat Disord. 2016;49(1):50\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStaab R, Campagna J, Ma J, Sengar A. Rapid refeeding in anorexia nervosa: A dialectic balance. Int J Eat Disord. 2022;55(5):653\u0026ndash;63.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKoerner T, Haas V, Heese J, Karacic M, Ngo E, Correll CU, et al. Outcomes of an Accelerated Inpatient Refeeding Protocol in 103 Extremely Underweight Adults with Anorexia Nervosa at a Specialized Clinic in Prien, Germany. J Clin Med. 2020;9(5):1535.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRichardson C, Huniewicz P, Paslakis G. Retrospective analysis of hypophosphatemia rates and other clinical parameters in patients with eating disorders. Eur Eat disorders Rev. 2021;29(2):193\u0026ndash;203.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKells M, Gregas M, Wolfe BE, Garber AK, Kelly-Weeder S. Factors associated with refeeding hypophosphatemia in adolescents and young adults hospitalized with anorexia nervosa. Nutr Clin Pract. 2022;37(2):470\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStrandjord SE, Sieke EH, Richmond M, Khadilkar A, Rome ES. Medical stabilization of adolescents with nutritional insufficiency: a clinical care path. Eat weight disorders. 2016;21(3):403\u0026ndash;10.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCuntz U, K\u0026ouml;rner T, Voderholzer U. Rapid renutrition improves health status in severely malnourished inpatients with AN - score‐based evaluation of a high caloric refeeding protocol in severely malnourished inpatients with anorexia nervosa in an intermediate care unit. Eur Eat disorders Rev. 2022;30(2):178\u0026ndash;89.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGjoertz M, Wang J, Chatelet S, Monney Chaubert C, Lier F, Ambresin AE. Nutrition Approach for Inpatients With Anorexia Nervosa: Impact of a Clinical Refeeding Guideline. JPEN J Parenter Enter Nutr. 2020;44(6):1124\u0026ndash;39.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMatthews K, Hill J, Jeffrey S, Patterson S, Davis A, Ward W, et al. A Higher-Calorie Refeeding Protocol Does Not Increase Adverse Outcomes in Adult Patients with Eating Disorders. J Acad Nutr Dietetics. 2018;118(8):1450\u0026ndash;63.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGibson D, Watters A, Cost J, Mascolo M, Mehler PS. Extreme anorexia nervosa: medical findings, outcomes, and inferences from a retrospective cohort. J Eat disorders. 2020;8(1):25\u0026ndash;10.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRio A, Whelan K, Goff L, Reidlinger DP, Smeeton N. Occurrence of refeeding syndrome in adults started on artificial nutrition support: prospective cohort study. BMJ open. 2013;3(1):e002173.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGarber AK, Cheng J, Accurso EC, Adams SH, Buckelew SM, Kapphahn CJ, et al. Short-term Outcomes of the Study of Refeeding to Optimize Inpatient Gains for Patients With Anorexia Nervosa: A Multicenter Randomized Clinical Trial. JAMA Pediatr. 2021;175(1):19\u0026ndash;27.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 is available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"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":"journal-of-eating-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"joed","sideBox":"Learn more about [Journal of Eating Disorders](http://jeatdisord.biomedcentral.com)","snPcode":"40337","submissionUrl":"https://submission.nature.com/new-submission/40337/3","title":"Journal of Eating Disorders","twitterHandle":"@JEatDisord","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Eating disorders, Anorexia nervosa, Adults, Inpatients, High calorie refeeding, Low-calorie refeeding, Refeeding syndrome, Length of stay","lastPublishedDoi":"10.21203/rs.3.rs-8537410/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8537410/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e Hospital admissions for individuals with eating disorders are increasing, yet adult inpatient nutritional restoration often relies on conservative low-calorie refeeding to avoid refeeding syndrome (RFS). Evidence from younger populations suggests that higher-calorie refeeding (HCR) may be safe and more efficient, but data from adults are limited. This scoping review mapped the extent, characteristics and safety of HCRs (≥1500 kcal/day) for people with eating disorders admitted to adult hospital wards.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e Five electronic databases were searched from July 2025 for studies published from January 2012–June 2025. Eligible studies included adults with a diagnosed eating disorder or mixed-age samples treated in adult wards, who underwent HCR on admission. The primary outcomes were RFS markers, particularly refeeding hypophosphataemia; the secondary outcomes were length of stay (LOS), weight gain and change in body mass index (BMI). Three reviewers independently screened the records and charted the data, and the findings were synthesised descriptively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e Of the 778 records identified, 11 studies met the inclusion criteria. Most of these studies involved retrospective cohorts, with three quasi-experimental before–after designs, which were performed in adult specialist or general inpatient settings across several countries. Together, they described 4,874 patients exposed to HCR, usually starting at 1,500–2,000 kcal/day and advancing as tolerated. Definitions and monitoring of RFS vary widely. No study reported deaths or clinically defined RFS attributable to HCR. Biochemical hypophosphataemia affects up to approximately one-third of patients, is usually mild and is managed with electrolyte supplementation. Four studies reported LOS; two reported shorter admissions and faster weight gain with HCR than with lower-calorie protocols did.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e Across observational studies, initiating HCR for people with eating disorders in adult hospital wards appears feasible and can be delivered without an obvious increase in clinical RFS while potentially reducing the LOS and enhancing weight restoration when combined with close monitoring and supplementation. Heterogeneity in RFS definitions, refeeding protocols and outcome reporting, and the absence of randomised trials limit confidence in these findings. Prospective studies using standardised RFS criteria and clearly defined HCR and comparator protocols are needed to guide adult-focused practice and policy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial registration: \u003c/strong\u003eNot applicable.\u003c/p\u003e","manuscriptTitle":"Can higher-calorie feeding protocols for patients with eating disorders admitted to an adult hospital ward be safely implemented to reduce the length of stay? 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