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).