Grant title
Long-term effectiveness of school-based obesity prevention: eight-year follow-up data of the Kiel Obesity Prevention Study (KOPS)
Scientific abstract
Background
Childhood obesity is a major public health problem. Since treatment of obesity is difficult and has shown low success rates, preventive measures are necessary. Recent preventive programs have shown small or no effect on childhood overweight. However, most were uncontrolled and only short-term effects were evaluated. Long-term effects of school-based interventions to prevent childhood overweight have been rarely investigated.
The importance of long-term evaluations over several years is reflected by the results of the French EPODE obesity prevention study where there was no effect between the intervention and control group after four years but 12-year follow-up data showed a significant lower prevalence of overweight in the intervention group when compared to the control group.
The Kiel Obesity Prevention Study (KOPS), a school-based intervention, was started in 1996 and students were followed over eight years. Follow-up at one and four years, suggested some limited but selective effects of school-based prevention of childhood overweight. The current study presents eight-year follow-up data of KOPS.
Objective
To evaluate eight-year outcome of school-based intervention on weight status, lifestyle and co-morbidities as part of KOPS.
Methods
Within a quasi-randomised controlled trial 240 intervention (I) and 952 non-intervention (NI) students at age six and 14 years were assessed in schools. Six nutrition units followed by 20 minutes running games were performed within the first year at school. Primary outcome was eight-year change in BMI-SDS (according to German reference). Effective intervention was tested using multilevel linear regression analysis.
Results
Eight-year changes in BMI-SDS were +0.18 and +0.22 with increases in prevalence of overweight from 8.3 to 10.4% and 7.0 to 11.2% in I and NI students. Cumulative eight-year-incidence of overweight was 5.9% and 7.1% in I and NI students.
There was no overall effect of intervention but a significant interaction was shown between the intervention and the socio-economic status (SES) which demonstrated that in high SES, eight-year change in BMI-SDS was in favour of I (-0.17 and +0.17 in I and NI; p<0.01). Intervention had no measurable effects on lifestyle and co-morbidities.
Conclusion
School-based health promotion has some favourable and sustained effects on eight-year changes in BMI-SDS being most pronounced in students of high SES families. The data argue in favour of further preventive measures.
Plain language abstract
Hypothesis
School-based intervention will have long-lasting effects on prevalence of overweight as well as on lifestyle variables and co-morbidities.
Background
The prevalence of obesity and its co-morbidities has steadily increased over the last 50 years. Thus, prevention of obesity is a public health agenda. There are only few long-term studies of controlled activities in the area of prevention of childhood overweight. The Kiel Obesity Prevention Study (KOPS) intends to characterise the determinants of childhood overweight and to assess the long-term effect of preventive measures within school.
Methods
Between 1996 and 2001 4997 5-7-year old children (41% of the total population of all first graders in 32 primary schools in Kiel) were investigated. In addition, health promotion was performed each year in three schools for first graders (nutrition education and active breaks). Altogether 780 children took place in the school-based intervention. 1,192 of the 4,997 5–7-year-old children (= 23.9%) were reinvestigated eight years later (ie 240 “intervention students” and 952 “non-intervention students”). Main outcome measures were nutritional status, lifestyle habits and risk factors of disease.
Key findings
Intervention had minor but favourable effects on eight-year changes in BMI-SDS. Socio-economic status (SES) was a confounder of intervention: students with a high SES background showed favourable long-term outcomes. Lifestyle habits were similar in intervention and non-intervention students.
However, eight-year changes in healthy dietary pattern, physical activity and media time consumption tended to be better in the intervention group when compared to the non-intervention group. Co-morbidities did not differ between intervention and non-intervention students.
Grant publications
- Clustering of lifestyle factors and association with overweight in adolescents of the Kiel Obesity Prevention Study
- Determinants of the prevalence and incidence of overweight in children and adolescents
- Soziale Ungleichheit, Migrationshintergrund, Lebenswelten und Übergewicht bei Kindern und Jugendlichen. [Social inequality, migration, and healthy environments as determinants of overweight of children and adolescents. Results of the Kiel Obesity Prevention Study (KOPS)]
- 15 Jahre Kieler Adipositas-Präventionsstudie (KOPS) – Ergebnisse sowie deren Einordnung und Bedeutung für die Prävention von Adipositas bei Kindern und Jugendlichen. [15 years Kiel Obesity Prevention Study – results and its importance for the prevention of childhood overweight]
- Eight-year follow-up of school-based intervention on childhood overweight – the Kiel Obesity Prevention Study
