Differences in weight loss and health outcomes among African Americans and whites in multicentre trials

The efficacy of behavioural lifestyle interventions (BLI) for weight loss and prevention and treatment of diabetes and hypertension is well established but may vary among racial/ethnic subgroups. This report reviews literature from 1990 to 2012 to determine if outcomes were similar among African Americans (AA) and whites participating in multicentre BLIs funded by the National Institutes of Health. We identified seven relevant trials that reported subgroup analyses for AA. On average, AA lost less weight at 6 months (AA: -1.6 to -7.5 kg; whites: -3.8 to -8.2 kg), but also had less or similar weight regain compared with whites. There were no reported differences between races in diabetes incidence. Three analyses reported no differences in blood pressure; however, a fourth reported that AA women were the only group that did not experience a significant change in blood pressure. Despite increased attention to cultural relevance, race-specific differences in weight loss persist in trials spanning 20 years; however, risk factor modification was similar across race/ethnic groups. Additional research is needed to understand the mechanisms of risk factor modification, and potential for weight change to promote even greater risk factor modification for AA than has been observed to date.