Type 2 diabetes affects 8 percent of U.S. adults, as well as a growing number of youth. Increased prevalence of diabetes will cause a serious increase in early morbidity, health care costs and lost productivity. There is now substantial evidence that diabetes can be delayed or prevented in high-risk individuals, making prevention a key target for clinicians, patients and policy-makers. This article examines the evidence regarding prevention of type 2 diabetes, with the purpose of providing clinicians with insights into the components of successful interventions. The authors conducted a MEDLINE literature search from 1980 to 2004, identifying four major clinical trials using lifestyle interventions and three using prophylactic medication. They reviewed the study designs, outcomes and aspects of the interventions that could be adapted for clinical practice.

Key Findings:

• The studies that focused on lifestyle intervention set modest goals for weight loss and physical activity, yet even modest weight loss resulted in significantly lower incidence of diabetes.
• Individualized counseling, with behavioral contracting and self-monitoring helped participants work toward their goals.
• Prophylactic medication reduced diabetes risk, but lifestyle interventions were more effective.

This study shows that clinical trials have demonstrated how diabetes can be prevented or delayed through lifestyle changes. Further research is needed on how best to adapt these cost-effective prevention programs for use in the clinical setting.