Abstract 53: Effect of Race / Ethnicity on Attrition and Weight Loss in a Behavioral Intervention

Abstract

Background: Race and ethnic disparities may contribute to differences in the prevalence of excess weight and adiposity. Thus, it is of clinical, public health, and ethical importance for interventions to demonstrate effectiveness for all persons, and if not demonstrated, to appropriately modify these interventions. Hypothesis: We hypothesize that attrition and weight loss in a behavioral intervention differs by race/ethnicity. Methods: Participants were adults with overweight/obesity (N=383, age=45.6±8.0 years, BMI=32.4±3.8 kg/m 2 ), with 68.9% self-identifying as non-Hispanic white (NHW) and 31.1% self-identifying as a race/ethnicity other than NHW (non-NHW). Randomization was to one of three weight loss interventions for 12 months: 1) behavioral intervention plus a prescribed energy-reduced diet (DIET), 2) DIET plus prescribed progression to 150 min/wk of moderate-to-vigorous intensity physical activity, 3) DIET plus prescribed progression to 250 min/wk of moderate-to-vigorous physical activity. Attrition was assessed across the intervention period. Weight loss was assessed at 6-months and 12-months. Results: Attrition at 6 months was 11.2%, with this being 8.7% for NHW and 16.8% for non-NHW (p=0.020). Attrition at 12 months was 15.9%, with this being 12.9% for NHW and 22.7% for non-NHW (p=0.015). For participants completing 6 months of the intervention, percent weight loss was greater in NHW (-10.8% [95% CI: -11.6, -10.1]) versus non-NHW (-7.8% [-9.0, -6.6]) (p<0.001), with this not differing by intervention condition (p=0.666). Similar findings were observed for participants completing 12 months of the intervention (NHW = -12.0% [95% CI: -13.0, -10.9]; non-NHW = -8.5% [95% CI: -10.2, -6.8]) (p=0.001). At 6 months, 83.4% of NHW and 66.7% of non-NHW achieved weight loss of ≥5% (p=0.001) and at 12 months 80.9% of NHW and 59.8% of non-NHW achieved weight loss of ≥5% (p<0.001). Conclusions: On average, a behavioral intervention results in significant weight loss in both NHW and non-NHW adults. However, weight loss is less and the percent of adults achieving a clinically meaningful weight loss of ≥5% is lower in non-NHW compared to NHW. These findings along with greater attrition warrant consideration when implementing a behavioral weight loss intervention. Whether this difference in weight loss also attenuates the beneficial effects on adiposity-related conditions warrants examination. Supported by the National Institute of Health (HL103646)