Researchers from John Hopkins Bloomberg School of Public Health and National Institute on Aging examined changes in American boys and girls (between ages 2-19) and by ethnic groups at the population level. They found that U.S. children and adolescents had increased adiposity (fatty tissue) measures including Body Mass Index (BMI), waist circumference, and triceps skinfold thickness. Heavier children/adolescents gained more fatty tissue (especially waist size), which was found to be most significant in African American girls and children between the ages 6-11. In conclusion, researchers believe that waist circumference is a better predictor of future obesity-related health risks (such as type 2 diabetes and heart disease in adulthood) than BMI alone.