Validity of triceps skinfold and relative weight as measures of adolescent obesity.

The ability of relative body weight and triceps skinfold thickness to indicate obesity in adolescents was analyzed in 169 males and 66 females, 12-17 years of age, whose percent body fat had been determined by underwater weighing. Using 25% body fat in males and 30% in females as the criterion for obesity, 31 males and 17 females were placed in this category. Of these, the triceps skinfold correctly identified 15 males and 4 females, and the relative weight identified 16 and 5, respectively. These anthropometric indicators, at the levels applied, are low in sensitivity (23-50%) but high in specificity (85-100%).