[Prevalence of overweight and obesity in Swiss adolescents]

Overweight and obesity are the most important modulators in the development of chronic diseases. Body weight status in adulthood is often already determined in childhood and adolescence. In this study we evaluate possible threats and the prevalence of overweight and obesity among students of the Kantonsschule Burggraben in St.Gallen. Different anthropometric parameters (e.g. size, weight, circumference of waist and hip, body composition by BIA) were assessed among 552 students and different life-style factors as well as risk factors were assessed with a self-administered questionnaire. Using the IOTF-definitions between 6.12-8.18% of students were overweight and 1.08-2.23% were obese. Male students with the highest media consumption (MC) (around 4 h/d) had a higher BMI (kg/m2) than students with lower MC (around 2 h/d) or the lowest level of MC (approximately 1 h/d) (22.83 +/- 0.46 kg/m2 vs. 21.51 +/- 0.21 kg/m2 and 21.60 +/- 0.39 kg/m2; ANOVA p = 0.008). Similarly body composition was affected: students with the highest media consumption had the highest amount of body-fat mass: 12.69 +/- 0.66% vs. 11.05 +/- 0.34% and 10.69 +/- 0.62% (ANOVA p = 0.026) compared to medium and low MC, respectively. There was no correlation between the BMI, the body fat mass and the MC among female students. According to the level of activity male students with a high level showed a significant lower BMI than students with a lower level of physical activity (21.70 +/- 0.21 kg/m2 vs. 22.05 +/- 0.33 kg/m2; p = 0.016). The body fat mass was also lower for higher levels of physical activity (9.57 +/- 0.65% vs. 12.69 +/- 0.86%). Among female students the level of physical activity modulated the body fat mass (high level 20.66 +/- 0.52% vs. low level 23.53 +/- 0.58; p = 0.005) but had no effect on the BMI. Risk factors for obesity such as physical activity patterns are established in childhood and early adolescence. Preventive strategies have to be implemented as early as possible.