In 2017, the proportion of overweight children and adolescents aged 6-12’ in Switzerland was 11.7%, and that of the obese ones was 3.3%, with no major differences between girls and boys. There were no relevant age differences in any of the weight groups by body mass index (BMI). Over time, the proportions of overweight (1999: 14.5%; 2017: 11.7%) and obese children and adolescents (1999: 2.2%; 2017: 3.3%) have remained relatively stable.

This indicator is part of the Monitoring System Addiction and NCD (MonAM) of the Federal Office of Public Health (FOPH).

Overweight and especially obesity (severe overweight) are among the risk factors for non-communicable diseases such as cardiovascular diseases, diabetes mellitus type 2, some types of cancer and musculoskeletal diseases. There is also an association with mental health and quality of life. Obese children are more likely to be overweight or obese in adulthood and to have related secondary diseases. Therefore, a healthy lifestyle with a balanced diet and sufficient exercise is particularly important for the prevention of overweight and obesity in children. However, in addition to diet and exercise, other causative factors of obesity such as stress, lack of sleep, medication use, hormone balance, microbiome and genetics need to be taken into account.


The body mass index BMI is calculated from data on a child’s weight and height (weight in kg / height in m2). In the data underlying this indicator, weight and height were measured in each case as part of a cross-sectional study.

International comparison tables (World Obesity - formerly IOTF, or Cole et al., 2000) were used to determine the categories. The curves were standardised to values at the age of 18. A BMI < 18.5 represents underweight, BMI 18.5-25 normal weight, BMI 25-30 overweight and BMI > 30 obesity.

The data need be put into perspective. Although the participating schools were selected to be representative of the different regions of Switzerland, the participation of the children was voluntary. This may have led to an overrepresentation of children whose parents are interested in the topic and therefore to an underestimation of the proportion of overweight and obese children. In the 2007 and 2012 surveys, 75% of the invited children and adolescents participated; in 2017, only 55% participated.

Since the 2005/06 school year, the BMI monitoring of Health Promotion Switzerland, in collaboration with the school medical services, has carried out comprehensive surveys of the BMI of schoolchildren in the cities of Bern, Basel and Zurich. These data provide a differentiated picture of the development of overweight and obesity over time by school level, gender and social background and may be used in addition to the data provided in this indicator.


  • ETH Zurich: Laboratory of Human Nutrition


  • ​Aeberli, I. et al. (2010). Stabilization of the prevalence of childhood obesity in Switzerland. Swiss Medical Weekly, 140:w13046: Study.
  • Aeberli, I. (2018). BMI, waist circumference and body fat measurements as well as NCD risk factors in 6 to 12 year old children in Switzerland. Final report for the attention of the Federal Office of Public Health (BAG)​. ETH Zürich, Zürich: Report.

Further information

  • Bringolf-Isler, B. et al. (2016). Schlussbericht zur SOPHYA-Studie. Swiss Tropical and Public Health Institute, Basel: Report (in German).
  • Cole, T.J. et al. (2000). Establishing a standard definition for child overweight and obesity worldwide: international survey. BMJ. 2000 May 6;320(7244):1240-3: Study.
  • Health Promotion Switzerland: BMI Monitoring (in German, French and Italian)
  • Health Behaviour of School-aged Children (HBSC Switzerland): Body weight and image

Media enquiries

Federal Office of Public Health FOPH
Tel. +41 58 462 95 05

Last updated