Effectiveness of a kindergarten-based obesity prevention intervention to reduce risk of overweight at school entry

BACKGROUND: Accelerated weight gain from two to six years of age is associated with overweight and obesity in adolescence. Kindergartens may play an important role in shaping early healthy behaviors, making this setting ideal for interventions aiming at preventing childhood obesity. OBJECTIVES: To examine the effectiveness of a kindergarten-based obesity prevention intervention on Body-Mass-Index (BMI) z-score and risk of overweight at school entry. METHODS: A kindergarten-based obesity prevention intervention group (n = 1755) was compared to a usual care group (n = 750). The intervention consisted of two workshops focusing on developing activities to promote healthy behaviors, delivered to kindergarten staff and parents. The children's weight and height were measured once during mandatory school health examination between ages five to seven years. Socioeconomic data were obtained from national registers. Group differences in BMI z-score and risk of overweight were analyzed, adjusted for socioeconomic data. RESULTS: No significant differences were found in BMI z-score (mean difference: 0.03, 95 % Confidence Interval (CI): -0.06, 0.12) or risk of overweight (risk ratio: 0.96, 95 % CI: 0.78, 1.19) between the groups. However, children with lower parental education showed a trend toward lower BMI z-score in the intervention group compared to the usual care group (P = 0.09). CONCLUSION: While the kindergarten-based obesity prevention intervention showed no overall effect on BMI z-score or overweight risk at the population level, children from families with lower parental education levels may have more benefit of the intervention.