Authors: Loneke T. Blackman Carr, Carmen Samuel-Hodge, Dianne Stanton Ward, Kelly R. Evenson, Shrikant I. Bangdiwala, and Deborah F. Tate
Introduction: Around two-thirds of adults in the United States are overweight or obese (68.8%). Among racial/ethnic subgroups, African American (AA) women are the most affected by overweight/obesity (82.1%). This disparity indicates a need for solutions, as unhealthy weight increases the risk of developing type 2 diabetes, cardiovascular disease, and some cancers. Behavioral weight loss interventions (BWI) are an effective solution that include diet, physical activity (PA), and behavior modification to produce clinically significant weight reduction (5%-10% of baseline weight).
African American, compared with non-Hispanic White (NHW), women consistently lose 2-3 kg less weight in BWI, which can reduce the potential to maximize health benefits. Reasons for the weight loss disparity are not well understood. Mixed findings on racial differences in dietary and PA changes during BWI, difficulty recruiting and retaining minorities, and a lack of conducting or reporting such analyses contribute to the knowledge gap. More evidence is needed to understand and reduce the racial weight loss disparity.
We conducted a secondary data analysis of a randomized controlled trial using BWI to examine the impact of race on women’s weight loss and weight-related behaviors. We hypothesized that: 1) NHW women would achieve greater weight loss than AA women; 2) diet, PA, and study engagement would differ by race such that NHW women would have more favorable changes compared with AA women at 4 months post-baseline. We further hypothesized that these changes would mediate the relationship between race and weight loss.
Key Findings
- Non-Hispanic women demonstrated significantly greater (approximately 3%) weight loss than African American women after 4 months.
- These differences are partly explained by two factors: Non-Hispanic women demonstrated a significantly higher change in their Eating Behavior Inventory scores than African American women, a measure of their weight control self-monitoring and dietary management behaviors. Additionally, they exhibited greater study engagement, as measured by the count of their website log-ins.
- However, greater understanding of these mechanisms and their complementary nature is required to reduce the racial disparities in this behavioral weight loss intervention.