Effectiveness of a behavioral weight management intervention by race, ethnicity, income, and education: a...

Racially and ethnically marginalized groups experience disproportionately high obesity rates, but are underrepresented in clinical trials of obesity treatments. Obesity treatments seem less effective for marginalized groups, but studies are characterized by small samples, clinic-based treatments, and little attention to socioeconomic position. We evaluated weight loss outcomes of a widely-available behavioral weight management program (Weight Watchers; WW) by race, ethnicity, income and education.

We performed an individual participant data meta-analysis of 11 WW intervention studies published from 2000-2025. T-tests compared weight loss between intervention and control participants within race, ethnicity, income and education subgroups. Among intervention participants, fixed effects multivariable regression estimated the odds of achieving a 5% weight loss across subgroups.

Here we show that among 2972 participants (19% Non-Hispanic Black, 7% Hispanic/Latine; 30% <$50,000/y) and a mean (SD) weight of 96.2 (18.1) kg, WW interventions produce significantly greater weight loss than controls in all subgroups at 3, 6, and 12 months. Within the intervention group, Non-Hispanic Black participants are significantly less likely to experience a 5% weight loss than Non-Hispanic White participants at 3, 6, and 12 months, but there are no differences by income or education.

A widely-available weight management program is more effective than controls for weight loss in all race, ethnicity, income, and education subgroups. However, the likelihood of clinically significant weight loss varies when comparing across racial and ethnic groups. These data can assist practitioners and patients when choosing evidence-based approaches to manage obesity among racially and ethnically marginalized groups.