Obesity is a major risk factor for type 2 diabetes. The prevalence of obesity in US adults, defined as a body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of 30 or greater, changed little between 1960 and 1980 (from 13% in 1960 to 15% in 1980). Subsequently, between 1980 and 2000, the prevalence of obesity in the United States doubled from 15% to 31%.1 Since then, there has been relatively little change in the prevalence of obesity among infants and toddlers, children and adolescents, or adults. Nevertheless, the prevalence of obesity is high with 8% of infants and toddlers, 17% of those aged 2 to 19 years, and 35% of US adults aged 20 years or older estimated to be obese.2,3