[Diagnosis of overweight and obesity in schoolchildren: utilization of the body mass index international standard].

OBJECTIVE To evaluate the agreement between the body mass index international standard and body fat for the diagnosis of overweight and obesity in schoolchildren. METHODS 528 schoolchildren between 6 and 10 years of age, of both sexes, had their weight and height measured. They were then classified as normal, underweight, overweight or obese using the body fat index for age. Body fat was estimated based on the sum of triceps and subscapular, triceps and calf skinfold measurements and waist and hip circumference. RESULTS Overweight and obesity were found in 21.2% of the girls and 18.8% of the boys. The average percentage of body fat in the normal children (17.7%) was statistically different from that of overweight (27%) and obese (29.4%) children (p < 0.02). The average waist and hip circumference also differed significantly between normal boys and girls (56.9 cm and 67.7 cm) and overweight children (65.9 cm and 77 cm) (p < 0.01). There was no significant difference between groups in terms of average waist to hip ratio. The percentage of body fat, waist and hip circumference were significantly correlated with body mass index (p < 0.01). CONCLUSION Body mass index for age was an adequate indicator of overweight and obesity in group studied, with a good agreement with body fat.