The main objective of this study is to investigate the effect of genetic and environmental parameters on racial/ethnic differences in aspects of insulin secretion and action. The genetic component will be modeled by estimating the degree of European genetic admixture (ADM) obtained from approximately 50 ancestry informative markers (AIMs). The environmental components will be modeled by measuring energy intake (food intake), energy expenditure (physical activity) and socioeconomic status.

Inclusion Criteria:

• African American, European American, or Hispanic American, aged 7-12, healthy, weight is equal to or greater than 25 Kg

Exclusion Criteria:

• Type 1 or 2 diabetes, polycystic ovary disease, disturbances in glucose or lipid metabolism disturbances
• Use of medication known to affect body composition or physical activity, diagnosis of genetic disorders known to affect body composition or fat distribution
• Use of tobacco, alcohol consumption in excess of 400 g per week
• Menstruated for more than a year prior to the recruitment; OR
• A medical history that counter-indicates inclusion of the study

120 African Americans, 120 European Americans and 120 Hispanic Americans (60 males and 60 females per group). To minimize the influence of puberty on SI and AIRg, recruitment will be limited to individuals between ages 7-12, a range that based on previous observations from our team, categorize children from Tanner stage 1 and 2.