Objective: To provide the specific weight loss outcomes for African-American, Hispanic, and white men and women in the lifestyle and metformin treatment arms of the Diabetes Prevention Program (DPP) by race-gender group to facilitate researchers translating similar interventions to minority populations, as well as provide realistic weight loss expectations for clinicians.

Methods and Procedures: Secondary analyses of weight loss of 2,921 overweight participants (22% black; 17% Hispanic; 61% white; and 68% women) with impaired glucose tolerance randomized in the DPP to intensive lifestyle modification, metformin or placebo. Data over a 30-month period are examined for comparability across treatment arms by race and gender.

Results: Within lifestyle treatment, all race-gender groups lost comparable amounts of weight with the exception of black women who exhibited significantly smaller weight losses (P < 0.01). For example, at 12 months, weight losses for white men (−8.4%), white women (−8.1%), Hispanic men (−7.8%), Hispanic women (−7.1%), and black men (−7.1%) were similar and significantly higher than black women (−4.5%). In contrast, within metformin treatment, all race-gender groups including black women lost similar amounts of weight. Race-gender specific mean weight loss data are provided by treatment arm for each follow-up period.

Discussion: Diminished weight losses were apparent among black women in comparison with other race-gender groups in a lifestyle intervention but not metformin, underscoring the critical nature of examining sociocultural and environmental contributors to successful lifestyle intervention for black women.