Different age-specific incidence and remission rates in pre-school and primary school suggest need for targeted obesity prevention in childhood.

Abstract

School entry marks a tremendous change in the children's life style, which might well be relevant for the emergence of overweight. Previous studies suggested a dramatic increase in the prevalence of overweight during this age. To compare the age-specific balance between the incidence and remission of overweight between pre-school and primary school age children. We combined the data of three studies that had been conducted within the setting of the compulsory school entry health examination in different parts of Germany: one covering retrospective cohort data from age 2 to school entry (n=5045), one prospective data from school entry to fourth grade (n=1235) and one comprising both (n=1194). We assessed the rates of incidence and remission of overweight and obesity from age 2 to school entry and from school entry to fourth grade. In pre-school age, the pooled incidence for overweight was 8.2% (95% confidence interval: 7.5, 8.9) compared with a remission rate of 62.6% (58.4, 66.7), yielding a prevalence at school entry of 10.7% (9.9, 11.5). In primary school age, the pooled incidence for overweight increased to 14.6% (13.1, 16.1), whereas the remission rate was reduced to 17.7% (13.8, 22.3), yielding a prevalence of 23.7% (22.0, 25.4) in fourth grade. A similar pattern was observed for obesity. While high remission rates balance incident overweight in pre-school years, the dramatic increase in the prevalence of overweight and obesity in primary school years reflects a higher incidence and even more a lower remission rate. Obesity prevention programs in primary school age are mandatory and need to address primary and secondary prevention elements.