[Thinness and overweight in children from Amsterdam: a trend analysis and forecast]

To determine the trends in prevalence of moderate and severe thinness, overweight and obesity in children living in Amsterdam between 2009 and 2013 and estimate prevalences for 2020.

Historical cohort study.

158,730 measurements of height and weight of 112,405 children from Amsterdam were analysed. Moderate thinness, severe thinness, overweight and obesity were determined using international BMI cut-off values. Trends were analysed using Generalized Estimating Equations (GEE) for two age groups: pre-schoolers (2 and 3 years) and school-aged children (5, 10 and 14 years). The 'self-projecting method,' which allowed us to extend former trends into the future, was used to estimate prevalences for 2020.

The prevalence of moderate thinness increased significantly in both age groups. The prevalence of severe thinness did not change. The prevalences of overweight and obesity declined significantly in both age groups. These trends were most evident in children of Dutch origin. Other ethnic groups also showed declining prevalences but not in both age groups or both categories of overweight. The prognosis for 2020 shows a further decline in the prevalence of overweight and obesity and an increase in the prevalence of thinness.

A decline in the prevalences of overweight and obesity was observed in Amsterdam children, including children of Turkish and Moroccan origin. The prevalence rates are still high, so investing in prevention remains necessary. The prevalence of moderate thinness also seems to be increasing. Continued monitoring of children in all BMI classes is therefore important.