Effect of a Culturally Adapted Behavioral Intervention for Latino Adults on Weight Loss Over 2 Years: A Randomized Clinical Trial

IMPORTANCE: Identifying effective weight loss interventions for Latino adults at risk of diabetes is of critical public health importance. OBJECTIVE: To determine whether a culturally adapted behavioral intervention for Latino adults was more effective than usual care for weight loss over 24 months. DESIGN, SETTING, AND PARTICIPANTS: In this randomized clinical trial, Latino adults with a body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of 24 or greater and a high risk for type 2 diabetes were recruited in primary care practices in the San Francisco, California, area, randomized to receive the Vida Sana intervention or usual care, and followed up for 24 months. The study was conducted from November 2015 to May 2019, and data were analyzed from July 2019 to Septmeber 2020. INTERVENTIONS: The treatment group received Vida Sana, a culturally adapted lifestyle intervention that included a family-based orientation session and 22 group sessions over 12 months. Participants were encouraged to use a wearable activity tracker and mobile applications to track their physical activity and dietary intake. Participants received monthly email messages for an additional 12 months. The control group received usual care. MAIN OUTCOMES AND MEASURES: The primary outcome was weight loss at 24 months. Secondary outcomes included weight loss at 12 months and achieving at least 5% weight loss at 12 and 24 months. Associations of baseline characteristics and intervention adherence with weight loss outcomes were also examined. RESULTS: Among 191 participants (mean [SD] age, 50.2 [12.2] years; 118 [61.8%] women; 107 participants [57.2%] of Mexican origin; mean [SD] baseline BMI, 32.4 [5.7]) randomized, 92 participants were randomized to the intervention and 99 participants were randomized to usual care. Of these, 185 participants (96.9%) completed 24-month follow-up. Mean (SD) weight loss did not differ significantly by group at 24 months (intervention: −1.1 [5.7] kg; control: −1.1 [7.1] kg; P = .93). However, mean (SD) weight loss was significantly greater in the intervention group (−2.6 [6.0] kg) than the control group (−0.3 [4.2] kg) at 12 months (mean difference, −2.1 [95% CI, −3.6 to −0.7] kg; P = .005). Intervention participants were more likely to achieve at least 5% weight loss than control participants at 12 months (22 participants [25.9%] vs 9 participants [9.2%]; P = .003), and participants who achieved at least 5% weight loss attended more intervention sessions than those who did not (mean [SD], 16.6 [7.6] sessions vs 12.4 [7.5] sessions; P = .03). CONCLUSIONS AND RELEVANCE: These findings suggest that among Latino adults with high diabetes risk, a culturally adapted behavioral lifestyle intervention was effective for weight loss over 12 months but not 24 months. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02459691