A digital app-supported general practitioner-led weight loss program improves food literacy and intake in adults in rural Germany: Secondary outcomes of the HAPpEN pragmatic trial

Obesity prevalence is rising globally and especially in rural areas. Interventions promoting dietary behavior change specifically in rural populations are urgently needed to address this issue. This analysis used data from HAPpEN, a multicomponent, general practitioner (GP)-led and digitally supported obesity management intervention specifically developed to support weight loss in rural adults. It tested whether (1) the intervention induced changes in food literacy and intake and their relationships to changes in body weight, (2) these effects were modulated by the preferred decision-making style, and (3) the intervention induced eating disorder symptoms. Only intervention completers (N = 61) were included in the analysis.Outcomes were assessed at baseline, six months into the program, and immediately after completing the one-year program. Several aspects of food literacy including daily food planning improved significantly after six months, although the total food literacy score only improved significantly after one year. Food intake improved significantly after six months and stayed stable thereafter. At six months, changes in food intake were also related to changes in body weight. Intervention effectiveness may have dependent on the preferred decision-making style. Eating disorder symptomatology was not worsened through the program.Successful weight loss induced by HAPpEN is likely driven by changes in food literacy and intake. Offering a range of target foods, graded tasks and several complementary intervention components allows for tailoring to varying patient needs, levels of knowledge and behavior, and therefore increases the likelihood for intervention success. This trial was registered at the German Clinical Trial Register (DRKS00033916).Competing Interest StatementThe authors have declared no competing interest.Clinical TrialDRKS00033916Funding StatementThis work was supported by the Bavarian Federal Ministry of Health, Care and Prevention (G31i G8000 2021/2630 23, 07.06.2022). The funder had no involvement in the study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the article for publication.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:The HAPpEN trial has been approved by the University of Bayreuth ethics committee (Az. O 1305/1 - GB).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.YesI 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).YesI have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.YesAll data produced in the present study are available upon reasonable request to the authorsANCOVAAnalysis of CovarianceANOVAAnalysis of VarianceBMIBody-Mass IndexE-PIDPreference for Intuition and Deliberation in Eating Decision-makingFFQFood Frequency QuestionnaireGPGeneral PractitionerHAPpENHausarzt-zentriertes Adipositas-Präventionsprogramm: Exercise amp; NutritionHEIHealthy Eating IndexPHQPatient Health QuestionnaireSPFLSSelf-Perceived Food Literacy Scale