Percentage of overweight is overestimated in children of short stature.

BACKGROUND: The prevalence of overweight and obesity has increased, not just in adults but also in children. In Japan, the percentage of overweight (POW) is widely used for the estimation and assessment of percentage body fat (PBF) for children. We examine whether there is a difference between normal height and short stature children in terms of the relationship between POW and PBF. METHODS: A total of 321 children of normal height (163 boys, 158 girls) and 106 children with short stature (78 boys, 28 girls) were assessed according to sex. Percentage of overweight was used to represent the degree of obesity. The PBF of the total body was examined by dual energy X-ray absorptiometry. RESULTS: According to their PBF, normal height subjects of both sexes were classified as obese if they had a POW of more than 20%. However, short-stature subjects of both sexes were not classified as obese until the boys had a POW of 40%, and girls had a POW of 35%, respectively. Thus, overweight or obesity is overestimated in short stature children in both males and females with the rule "POW above 20% is recognized as obesity." CONCLUSIONS: Percentage of overweight is commonly considered as a good surrogate measure for determining overweight and obesity in children of both sexes. However, this study has clarified that body fat accumulation is overestimated in children with short stature when using the POW measurement.