Risk factors for overweight and obesity in Swiss primary school children: results from a representative national survey

Obesity is a global epidemic affecting around 10 % of 5- to 17-year olds. With the causes for obesity being multifactorial, a better understanding of the influencing factors is essential for effective treatment and prevention programs. The aim of this study was therefore to identify specific risk factors for overweight and obesity in children in Switzerland. A nationally representative sample of children aged 6-12 years was recruited (n = 2724). Height and weight were measured to calculate BMI (kg/m(2)). In addition, a questionnaire was distributed to all children asking about their physical activity, media consumption, and dietary habits as well as some parental factors. The prevalence of overweight and obesity in boys was 11.8 and 7.5 %, respectively, and in girls, it was 11.9 and 5.7 %. In univariate analyses, a number of parental, dietary, and activity factors were shown to be associated with BMI category. Based on a multinomial logistic regression, parent nationality and media consumption were the most important factors predicting obesity in boys, while in girls it was parental education, nationality, and physical activity. We have demonstrated that parental nationality and education play an important role in the development of childhood obesity, together with media consumption and physical activity. However, risk factors are also different according to child gender. Thus, an important target group for the treatment and prevention of childhood obesity in Switzerland are immigrant families, and the problem needs to be tackled differently in boys and girls as their risk factors are not the same.