Introduction It is well known that sedentary habits are associated with the risk of obesity and overweight. Many efforts have been made in Portugal to ameliorate exercise habits and to reduce sedentary habits of children and adolescents. The objective of this study was to characterise time spent watching TV or using the computer as well as time spent exercising and to relate them to dietary status and to determine differences between sexes and ages.
Materials and Methods Application of a questionnaire to 518 students from third to sixth grade in four public schools. Students self-reported height and weight data, as well as TV watching, computer use and physical activity habits. Self-reported height and weight were converted to body mass index percentile according to the Centers for Disease Control and Prevention’s classification criteria.
Results 29.8% of the children were obese or at risk of overweight. 48.6% of the children use the computer >1 h/day (55.9% of the boys vs 41.4% of the girls and 40.9% ⩽10 years vs 61.3% >10 years; p<0.05) and 63.8% watch TV >1 h/day (68.1% of the boys vs 59.1% of the girls and 56.5% ⩽10 years vs 74.9% >10 years; p<0.05) 70.5% do gymnastics ⩾2 times/week or more (73.1% of the boys vs 67.7% of the girls and 70.6% ⩽10 years vs 70.3% >10 years).
Conclusion Boys and older children watch more TV and use more computers. No difference was found concerning physical activity. No association was found between obesity or risk of overweight and more time spent in sedentary activities.