[Factors associated with obesity in school children]

To analyze the relationship between obesity, physical activity and hours of sleep in schoolchildren and parental schooling and obesity.

We measured the weight, height, body mass index and adiposity (subscapular to triceps skinfold ratio) of children. The children were classified as normal, underweight, overweight or obese, according to body mass index per age. Four hundred and fifty-two schoolchildren were evaluated; 68 children with excess weight and obesity and 97 normal children were selected to answer a questionnaire regarding daily physical activity and sleeping hours, as well as parental schooling, physical activity, weight and height.

The prevalence of excess weight and obesity was of 21.1% in boys and 22.9% in girls. Adiposity was different between normal children and the other groups (p < 0.01). In children with excess weight and obesity, adiposity was directly correlated with daily sitting hours and inversely correlated with daily sleeping hours (p < 0.05). Schooling was lower in mothers of overweight and obese children was lower than in mothers of normal children (p < 0.01). The frequency of excess weight and obesity in the parents of overweight/obese children was higher than in the parents of normal children (p < 0.01). Most parents had a sedentary life style.

We observed an association between excess weight and obesity in children and inactivity. The time spent sleeping was a positive factor for maintaining a balance between weight and height. Maternal schooling and the presence of excess weight/obesity in parents were significantly associated with childhood obesity.