Prevention strategies have been developed to take advantage of the metabolic and behavioral risk factors for type 2 (non-insulin-dependent) diabetes which have been identified in research with the Pima Indians and elsewhere. Obesity, impaired glucose tolerance, hyperinsulinemia, physical inactivity, and high fat diet have been implicated as risk factors for type 2 diabetes. Since these factors are potentially reversible with behavioral and pharmacologic therapy, strategies for prevention have been developed and will be tested. This project is a multicenter randomized clinical trial of prevention of type 2 diabetes in overweight persons with impaired glucose tolerance known as the Diabetes Prevention Program. The coordinating center is at the George Washington University. During the project year treatment of volunteers has continued in four American Indian communities in collaboration with the Indian Health Service. Plans are being initiated for study close-out, publication of final results, and post-study implementation of findings.