Effects of a combined diet and physical activity intervention (the ALAPAGE program) on dietary diversity and lower-limb muscle strength in community-dwelling older people: a pragmatic randomized controlled trial

Diet and physical activity are key components of healthy aging. We aimed to evaluate the effectiveness of a combined diet and physical activity intervention (the ALAPAGE program) in improving dietary diversity (proxy for the nutritional quality of individual diets) and lower-limb muscle strength (LLMS, a predictor of the ability to perform activities of daily living) among community-dwelling adults aged ≥ 60 years in France. The ALAPAGE program comprised a 7-week intervention period with weekly collective sessions supervised by a dietician and/or a qualified physical activity professional, followed by 12 weeks of unsupervised activity. Its effectiveness was assessed through a cluster-randomized controlled trial conducted in 2022–2024. Clusters of groups of approximately 10 participants were allocated to either an intervention arm or a control arm (2:1 ratio). Primary outcomes were (1) dietary diversity assessed with the ORCHID score (each assessment based on two 24-hour dietary recalls and a simplified food frequency questionnaire), and (2) LLMS, assessed by the 30-second chair stand test. Assessments were conducted at baseline (T0), 7 weeks (T1, dietary diversity only), and 3 months (T2). A difference-in-difference (D-I-D) analysis, adjusted for covariables, was used to evaluate the specific impact of the intervention over time, compared to the control arm. The analysis included 376 participants: 254 (26 clusters) in the intervention arm and 122 (12 clusters) in the control arm. At baseline, the ORCHID score and LLMS did not differ significantly between the two arms. The ORCHID score improved significantly with time in both arms (intervention: +10% and + 16% increase at T1 and T2 respectively, control: +4% and + 11%) with no significant difference between the arms. LLMS improved between T0 and T2 in both arms (intervention: +15%; control: +5%), with a statistically significantly greater increase of 1.3 chair stands over 30 s in the intervention vs. the control arm ( P = 0.005). While dietary diversity improved similarly in both arms, the intervention-specific improvement in LLMS - a parameter associated with functional capacity - suggests the ALAPAGE program has potential as a preventive public health approach for contributing to healthy aging in community-dwelling older adults. ClinicalTrials.gov Identifier: NCT05140330, November 4, 2021.