(PTFS01-04-25) Study Protocol: Feasibility and Efficacy of an 8-Week Family-Based Whole Foods Diet Intervention to Reduce Body Adiposity in Adolescents With Obesity

Objectives: Whether a family-centered whole foods diet that limits ultra-processed foods can reduce body adiposity (i.e., fat mass, body weight) in adolescents with obesity is unknown. This protocol describes the recruitment and process methods of an ongoing study testing the feasibility and acceptability of a whole foods diet in adolescents and their families.

Methods: A parallel-group randomized clinical trial (RCT) is underway for 30 adolescent-parent pairs being recruited to test the effects of a whole foods diet pattern on 1) adolescent adiposity measured via DXA to estimate fat mass and anthropometry to estimate weight, BMI z-scores, and waist circumference, and 2) adolescent and parent diet quality scores via the 2020-Healthy Eating Index measured from multiple 3-day food diaries. Surveys and focus groups will establish how social determinate of health (SDOH) factors (e.g., income, education, food security, etc.) and individual/family needs and preferences influence diet adherence. The intervention group will participate in an 8-week non-calorie restricted whole foods diet adapted from the Dietary Guidelines for Americans MyPlate plan that limits ultra-processed foods to meet daily food group targets (i.e., fruits, vegetables, proteins, dairy, grains; limits on sugar/saturated fat). Families will receive customizable menus and bi-weekly grocery deliveries to their homes and will meet bi-weekly with the study dietitian to discuss meal planning and preparation. The control group will receive a single dietetic consultation focused on MyPlate adoption. An intent-to-treat analysis will be conducted to assess the primary endpoint of change in body adiposity over 8 weeks analyzed with DXA and secondary endpoints including anthropometry and diet quality. Qualitative focus groups will be conducted to assess how SDOH factors and individual/family needs and preferences influence diet adherence across the study period.

Results: The study has received Institutional Review Board approval. Recruitment activities will start February 2025.

Conclusions: Data will be generated to guide a fully powered RCT of our whole foods intervention to assess long-term effects on adiposity and metabolic outcomes and assessment of SDOH influences to support long-term adherence.

Funding Sources: NIH, Vanderbilt Nursing School