Body weight and height of Japanese boys and girls aged 12–14 years were measured to calculate the prevalence of obesity, leanness and anorexia nervosa. In boys, the prevalence of obesity as well as leanness was significantly higher in the areas where population density was lower and among the boys who attended schools with smaller numbers of pupils. In the girls, these findings were similar to the boys. On the other hand, anorexia nervosa was found in girls only more commonly in the areas with higher population density and in the larger schools. These results suggest that higher prevalence of obesity in certain subjects may be associated with increased numbers of leanness but not with anorexia nervosa.

Concerns with eating were studied in 130 Japanese boys and 125 girls aged 6–18 years using the Simplified Eating Attitudes Test (s-EAT). The s-EAT scores in girls slightly increased with age. The mean scores in girls at age 10 years or older were significantly higher than in boys of the same age, suggesting that pubertal girls have more concerns with eating. On the other hand, s-EAT scores in boys that were not overweight decreased as they grew older, contributing, at least partly, to the sexual difference in eating behavior. The mean scores in overweight boys were higher than in boys that were not overweight. The score in boys correlated significantly with weight though there was no significant correlation in girls. These results suggest that, in addition to increased concerns with eating in girls, decreased concerns with age in boys is one of the causes of the sexual difference in eating behavior, especially during puberty. Eating behaviors in girls seem to be less influenced by changes in body weight than in boys.

Perceived actual body weight and perceived ideal weight were assessed in 255 Japanese children and adolescents (130 boys, 125 girls) aged 6 years through 18 years using the drawing test to clarify whether they wanted to be thinner or to gain weight. More than half (68%) of the girls attending high school and 41% of the elementary school girls perceived their ideal weight to be less than the standard. The mean difference between the perceived actual weight and the ideal weight was positive in the high school girls of normal weight as well as in the overweight girls, meaning that even the normal-weight girls wanted to lose weight. The difference was also slightly positive in the underweight girls. The difference in the high school boys was negative, demonstrating that they wished to gain weight. It is suggested that girls want to lose weight even before adolescence; this tendency becomes more prominent in the high school period and is mostly unrelated to their own weight.

We measured body weight, height, and skinfold thickness (SFT) at ulnar, triceps, subscapular and suprailiac regions in 1,656 Japanese children aged 3-11 years. Means of SFT in boys and girls with normal weight exhibited similar changes with age to Caucasian children. However, nadirs of SFT were observed 1 year earlier and means at 11 years were slightly higher in Japanese. Correlation coefficients between SFT and excess weight (EW) were high in boys and girls when EW was more than 10 %. Some children with EW of more than 10 % had abnormal SFT. Skinfolds in all children with EW of 30% or more were beyond the normal limits. In this study, normal ranges of SFT in Japanese children are demonstrated and their racial characteristics are compared to Caucasians. It is suggested that children with EW of 10-30% are heterogenous and determination of fat volume is essential to confirm the diagnosis of obesity in these subjects.

Overweight patients with Ullrich-Turner syndrome (UTS) and control children with similar weight/height and indices of overweight were studied to clarify the unique fat distribution in the syndrome. Triceps and ulnar skin-fold thickness (SFT) in UTS patients was significantly less than that of obese children without the syndrome. The means of SFT at the subscapular and paraumbilical regions were also less in the patients than control girls, though significance was not documented. Thus, increased body weight in UTS children seems mainly to be due to excess of adipose tissue, not in the limbs but on the trunk, and/or due to the increment of lean body mass.