Concept of chemical immaturity in body composition estimates: Implications for estimating the prevalence of obesity in childhood and youth

This paper estimates the prevalence of obesity in 6–8‐year‐old children, 13–15‐year‐old youth, and 18–19‐old adults by using skinfold data of the National Nutrition and Health Examination Survey. Obesity is defined as above 25% fat in males and above 32% fat in females. Skinfold equations used to estimate the fat cotent at each age were based on a multicompontent approach that used body density, body water, and bone mineral. The prevalence of obesity in the U.S. population was found to be much lower in children than in youth and young adults and to increase from 1 in 20 in childhood to 1 in 5 in adulthood.