Diabetes Prevention Program (DPP) and the Action for Health in Diabetes (Look AHEAD) Study: Lessons Learned

Abstract

The Diabetes Prevention Program (DPP) and the Action for Health in Diabetes (Look AHEAD) Study were important, large, randomized trials that evaluated the effects of a lifestyle intervention, including diet and physical activity, in persons at risk for or with type 2 diabetes. The DPP Study found that a lifestyle intervention targeting ≥7% weight loss and ≥150 min/week of physical activity effectively reduced diabetes incidence by 58% over an average of 2.8 years. Though weight loss was a stronger predictor of decreased diabetes incidence in DPP, achieving the targeted 150 min/week of physical activity predicted greater weight loss, was easier for participants to achieve (vs. the weight loss target), and decreased diabetes risk by 44% even when weight loss and dietary fat goals were not achieved. These findings strongly support physical activity for diabetes prevention. The Look AHEAD Study evaluated whether a lifestyle intervention targeting ≥7% weight loss and ≥175 min/week of physical activity could reduce major cardiovascular events in adults with preexisting diabetes. After an average 9.6 years of follow-up, the lifestyle intervention was not effective for reducing cardiovascular events as compared to the control group. Despite the failure to find a benefit on the primary outcome, increases in physical activity and, to a greater extent, cardiorespiratory fitness were independently related to more weight loss, better glycemic control, reduced cardiovascular risk factors, and increased health-related quality of life among Look AHEAD Study participants. Thus, physical activity that increases fitness remains an important part of treatment recommendations for adults with type 2 diabetes.