Androgyny in fat patterning is associated with obesity in adolescents and young adults.

Recent work suggests that android or male-type obesity is characterized by fat cell enlargement on the trunk and upper body. This implies adult differences in patterns of body fat distribution may have developmental origins connected with differences in maturation or age of onset of obesity. To investigate this, we studied adolescent females (N = 455, 12 years), males (N = 527, 14 years) and young adults (N = 393 females and N = 413 males, 17 years) of the US Health Examination Survey. Five skinfolds and five maturity indicators were available. Individuals were classed as normal weight, overweight or obese on the basis of the body mass index (WT/HT2). Fat patterning was studied by principal components analysis of the log residual skinfold thickness at the five sites, which revealed trunk/extremity and upper/lower trunk fat distribution components in all sex/age groups studied. The means of both components were significantly (P less than 0.05) greater in obese than in normal weight individuals indicating that obesity in adolescence and young adulthood consists of fat concentrated on the upper aspect of the trunk. The effect was independent of maturity, which was a significant correlate of the trunk/extremity patterning component only and in males only. Advanced physiological maturity is probably not a determinant of adult patterns of body fat distribution, but obesity which occurs in adolescence may be.