The increase in child obesity in Switzerland is mainly due to migration from Southern Europe - a cross-sectional study.

BACKGROUND: Novel height, weight and body mass index (BMI) references for children in Switzerland reveal an increase in BMI compared to former percentile curves. This trend may be the result of children with parents originating from Southern European countries having a higher risk of being overweight compared to their peers with parents of Swiss origin. We examined the association of generational, migration-related and socioeconomic factors on BMI in Switzerland and expect the results to lead to more targeted prevention programs. METHODS: From contemporary cross-sectional data, we calculated subgroup-specific BMI percentiles for origin. Results for children of Swiss origin were compared with historical BMI data from Zurich. We tested for the association of overweight and obesity with origin and compared the distributions of BMI percentile ranks. Logistic regression analyses were applied to predict probabilities of being overweight or obese by origin and the Swiss neighborhood index of socioeconomic position (SSEP). RESULTS: Compared to the BMI from two generations ago, the newly calculated BMI increased only slightly for children with both parents from Switzerland; 1.2% of these girls and 1.6% of these boys are obese. In the Swiss population, 13% of the children have parents from Southern Europe and the proportion of obesity is 57 and 42% in these boys and girls, respectively. Their BMI medians correspond to those of their parents' countries of origin. For the probability of being overweight or obese, the SSEP differences are less important than the status of origin. CONCLUSION: We identified children with both parents from Southern Europe as the main influence driving the increase in BMI in Switzerland over the past 50 years. A differentiated consideration of the proportions of various migrant groups within cross-sectional samples is essential when monitoring BMI. Ignoring fluctuations can lead to false conclusions.

Contemporary height, weight and body mass index references for children aged 0 to adulthood in Switzerland compared to the Prader reference, WHO and neighbouring countries.

Background: In 2011, WHO growth curves replaced those of Prader and colleagues (First Zurich longitudinal study) in Switzerland.Aim: To present contemporary height-, weight- and body mass index (BMI)-for-age references reflecting children's growth in modern Switzerland.Subjects and methods: Cross-sectional sample comprising 30,141 boys and girls aged 0-20 years measured between 2012 and 2019. Height, weight and BMI reference curves were created using the LMS method. Derived percentiles were compared with those of Prader, WHO and neighbouring countries.Results: Growth in the first 5 years is almost identical with Prader curves. Thereafter children are taller, yet their final height is only about 1 cm higher. Today's children, in particular boys, are considerably heavier. In comparison with WHO growth references, Swiss children are taller from the second year until adulthood; the WHO 3rd percentiles lie about 4 cm below those of our updated references. Weight and BMI median percentiles from our sample are similar to those of WHO and higher than the Prader curves. However, the course of the 97th BMI percentile WHO curves extends well below the 97th percentile of the updated Swiss curves.Conclusion: This study provides contemporary reference data for assessing individual growth based on height, weight and BMI of Swiss children.

Strength training and physical activity in boys: a randomized trial.

BACKGROUND: In developed societies levels of daily physical activity (PA) among school-age children are decreasing. This implies risk factors for cardiovascular and metabolic diseases. Specific strategies to improve levels of PA are needed. In prepubertal boys there is evidence that strength training increases spontaneous PA outside of training. METHODS: A total of 102 schoolchildren (age 10-14 years) in Switzerland were randomly assigned to physical education classes or to participate twice weekly at a guided strength training program for 19 weeks. Spontaneous PA energy expenditure (PAEE; 3axial accelerometry for 7 days), leg and arm strength, and body composition (dual energy radiograph absorptiometry) were measured at baseline, after 19 weeks of training intervention, and after 3 months of washout. RESULTS: There were no significant differences between the groups at baseline. In the intervention group, PAEE increased by 10% from baseline to end of training in boys (P = .02), but not in girls. Leg and arm strength were increased owing to training intervention in both boys and girls. All other variables were unchanged. Baseline PAEE was significantly negatively correlated with changes of PAEE. CONCLUSIONS: Targeted strength training significantly increases daily spontaneous PA behavior in boys. The less active children showed the greatest increase in spontaneous PAEE. Girls showed a similar increase in strength, but not in spontaneous PAEE. This may be explained by their earlier pubertal development. Strength training may be a promising strategy in schools to counteract decreasing levels of PA.