The objectives of PROP-ABC are to gain a fuller understanding of the natural history and predictors of early glucose abnormalities, determine the role of race during the second wave of glycemic progression, and to access the time dependency of reversibility of prediabetes. The study tests 4 hypotheses: 1) Among offspring of parents with type 2 diabetes, early progression from normal to impaired glucose regulation (within 5 yr) occurs in the highest-risk subjects independently of race, whereas late progression (5-10 yr) displays racial disparities, and is predicted by physiological, biochemical and behavioral markers; 2) Early microvascular complications, peripheral vascular disease (PVD), and endothelial dysfunction manifest during transition from normal to impaired glucose regulation, display racial disparities, and are predicted by glycemic and nonglycemic factors; 3) The "metabolically healthy" insulin-sensitive obese (ISO) phenotype displays racial disparities in its association with cardiometabolic risk factors and incident dysglycemia among African-Americans and Caucasians offspring of parents with type 2 diabetes; and 4) Duration of the prediabetic state is a major determinant of, and is inversely related to, the efficacy of lifestyle intervention to induce regression of the prediabetic phenotype and restoration of normal glucose regulation. Participants with prediabetes and others who develop prediabetes during PROP-ABC will receive Intensive Lifestyle intervention (ILI).