Objective: To estimate the prevalence of overweight, obesity and nutritional habits in schoolchildren aged 10-18 years.
Methods: Contemporary, cross-sectional, population-based study, with a stratified probabilistic sample of secondary schools in Porto Alegre comprising a total of 511 schoolchildren. Data on family risk factors, anthropometrics and eating habits were collected.
Results: The prevalence of excess weight was 27.6 % among the schoolchildren, with 17.8 % being overweight (BMI > or = 85th and <95th percentile) and 9.8 % obese (BMI > or = 95th percentile). Overweight was more prevalent in females (19.9 %) and obesity in males (11.8 %). Children who ate fewer meals per day tend to be more obese (mean: 3.51 (sd 1.14) v. 4.22 (sd 1.01) meals/d for students with normal weight). The mean weekly intake of unhealthy foods was 3.25 times for soft drinks, 2.91 for fried foods and 4.01 for sweets. The intake of skimmed milk (38.9 %) and diet soft drinks (20.9 %) was greater among obese children.
Conclusion: Overweight and obesity are increasing even in developing countries such as Brazil. Although many families are already taking measures towards healthier health habits, preventive actions must be considered a priority, with an emphasis on education, in order to avoid the need to treat obesity and its significant burden in the near future.