MedDiet-SN & MedDiet-WLBRIDGE & Friends Trial

Aim 1. Conduct a 6-month (24-session) RCT comparing MedDiet-WL to MedDiet-SN among 268 older adults with obesity (50-79 years, BMI = 30-50 kg/m²). We hypothesize that 1) Participants in MedDiet-SN will show improvements in bodyweight/BMI and body fat compared to MedDiet-WL at post-intervention (6-months), 2) Participants in MedDiet-SN will show improvements in diet (diet quality) and physical activity (step counts) compared to MedDiet-WL at post-intervention (6-months), and 3) Participants in MedDiet-SN will maintain these improvements at 12-months.

Aim 2. Characterize and compare differences in weight management information dissemination by 268 randomized to MedDiet-WL and MedDiet-SN. We hypothesize that MedDiet-SN participants will share information to more network members compared to participants in MedDiet-WL.

Aim 3. Compare MedDiet-SN and MedDiet-WL in 268 network members. We hypothesize that MedDiet-SN network members will show, greater improvements in BMI, body fat, diet, and physical activity than MedDiet-WL network members at 6 months. We will explore how effects may vary by network (e.g., density, relationships), and messaging characteristics (e.g., modality).