Four-year follow-up of school-based intervention on overweight children: the KOPS study

To evaluate the 4-year outcome of a school-based health promotion on weight status as part of the Kiel Obesity Prevention Study (KOPS).

Within a cluster-sampled quasi-randomized controlled trial, 1764 children at 6 and 10 years of age were assessed between 1996 and 2005 in 32 primary schools in Kiel, North Germany. Six nutrition units followed by 20-minute running games were performed within the first year at school. Prevalence, incidence, and remission of overweight were main outcome measures.

The 4-year change in BMI was +11.6%, with increases in prevalence of overweight and obesity from 5.2% to 11.1% and 3.9% to 5.1%, respectively. Cumulative 4-year incidence of overweight and obesity was 9.2% and 3.1%, respectively. Intervention had no effect on mean BMI. The effect on prevalence was significant in children from families with high socioeconomic status [odds ratio (OR), 0.35; 95% confidence interval (CI), 0.14 to 0.91] and marginally significant in children of normal-weight mothers (OR, 0.57; 95% CI, 0.33 to 1.00). Cumulative 4-year incidence of overweight was lower only in intervention children from families with high socioeconomic status (OR, 0.26; 95% CI, 0.07 to 0.87). Remission of overweight was most pronounced in children of normal-weight mothers (OR, 5.43; 95% CI, 1.28 to 23.01). Prevalence of underweight was unchanged. The intervention had minor but favorable effects on lifestyle.

A school-based health promotion has sustainable effects on remission and incidence of overweight; it was most pronounced in children of normal-weight mothers and children from families with high socioeconomic status. There was no effect on obesity. The data argue in favor of additional measures of prevention.