Addressing challenges in selecting dietary risk factor-outcome pairs for health impact assessments: Developing an evidence database and novel approach to dose-response extraction

Abstract Dietary health impact assessments are valuable decision-support tools for action on population-wide dietary shifts. These assessments rely on epidemiological evidence to estimate associations between dietary risk factors and health outcomes. However, the review and selection of evidence poses several challenges including a lack of systematic approaches to risk-outcome pair selection and ability to extract harmonised dose-response data from scientific papers. To address these challenges, this work aimed to 1) develop a database of dietary risk factor dose-response curves by updating the Nordic Nutrition Recommendations 2023 (NNR2023) evidence base and 2) propose a novel extraction method for non-linear dose-response curves. The NNR2023 scoping review methodology was replicated and risk-outcome pairs were selected according to modified NNR 2023 criteria. Non-linear relationships were estimated by extracting data points with an open-source graph reader and fitting piecewise constant functions to the extracted points. From the selected updated studies and original NNR2023 evidence, 101 risk-outcome associations were included, of which 44 were non-linear, and one quarter included beverages. Around half of the associations reported levels of at least mid-range evidence certainty. The provided database and methodology contribute to increased transparency and provide a standard approach to evidence selection and use in health impact assessments. Competing Interest Statement The authors have declared no competing interest. Funding Statement This study was partly funded by the Danish Ministry of Food, Agriculture and Fisheries (AEJ). Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability All data produced in the study are available online at Zenodo.