Obesity is a health problem of considerable magnitude. Ninety-four black obese women currently participating in a lifestyle intervention study were used to determine what relationship exists between hyperinsulinemia (determined at baseline) and change in body mass index (BMI) (at 16 weeks) controlling for the variables: baseline BMI, treatment group, and physical activity level. The subjects were divided into two groups based on baseline fasting serum insulin levels, (normoinsulinemic ⩽ 25 μU/ml and hyperinsulinemic > 25 μU/ml), and a regression analysis was used to determine what relationship exists between fasting serum insulin level and change in BMI. The regression analysis found that baseline fasting serum insulin level was not significantly related to the mean change in log of BMI (t = 0.415, p > 0.05) controlling for the variables: log of BMI at baseline, treatment group, and physical activity level. The analysis did find that the entire regression model (log of BMI at baseline, treatment group, physical activity level, and insulin level) explained 90% of the variation in the mean change in log of BMI (p < 0.05). In this study, it appears that hyperinsulinemia (determined at baseline) does not need to be accounted for when targeting obesity treatment interventions for this population. By excluding factors that do not affect change in BMI, it is hopeful that those factors which do affect change in BMI can be identified.