The primary aim of this proposal is to implement and evaluate a diabetes prevention program for low income, Latino patients at high risk of developing diabetes. Risk for diabetes will be defined by the use of the predictive equation developed by Stern and colleagues (including family history, ethnicity, gender, BMI, SBP, HDL and FBS), and primary outcomes will be a reduction in risk as defined by the same equation, and weight loss. The patients will be those of the Greater Lawrence Family Health Center (GLFHC) in Lawrence, Massachusetts, a community-based healthcare network affiliated with the UMass Medical School. In this two-condition randomized clinical trial, the intervention condition will utilize group classes that incorporate literacy-sensitive, culture-specific intervention strategies for improving diet and physical activity behavior, and designed to produce lasting weight loss and a reduction in diabetes-related risk factors. The program also will utilize cooking classes and individual in-person and telephone follow-up sessions. All interventions will be based on social-cognitive theory and a patient-centered counseling model. The study population will consist of 400 Latino pts at increased risk for diabetes. Participants will be recruited by provider referral; contacts with relatives of diabetic patients, community publicity, and targeted mailings. Random assignment by household will be to a usual care condition (UC) or to the intervention condition (IC). The patient is the unit of analysis. The IC will be implemented by bilingual nutritionists who will be trained in the intervention content and delivery strategies. Primary endpoints at two years of follow-up will include a 10% reduction in 7.5 year risk of diabetes as predicted by the Stem equation, and weight loss. Secondary outcomes will include: changes in fasting blood sugar, LDL-and HDL-cholesterol, SBP, Hemoglobin A1C levels. In addition to the primary endpoint measures, assessments will also include multiple 24 hour recalls for diet and physical activity, and measures of depression, social support, and quality of life. All assessments will be oral, and delivered in either Spanish or English. The study will be a collaborative effort between the UMass Medical School, the GLFHC, and the research laboratories at UMass-Lowell.