Health and nutrition education in primary schools of Crete: follow-up changes in body mass index and overweight status.

The current study examines the long-term effects of a school-based 'Health and Nutrition Education programme' on body mass index (BMI) changes and the prevalence of overweight. The intervention group consisted of all pupils registered in the first grade of two counties of the island of Crete in 1992, while all pupils registered in a third county formed the control group. For evaluation purposes, a representative sample was examined at baseline (1992) following the 6-y intervention (1998) and 4 y after the programme's cessation (2002). The data presented here are based on pupils with full anthropometrical data in all three examination periods (284 intervention group pupils and 257 control group pupils). Former intervention group pupils had lower average BMI (by 0.7 kg/m2, s.e. 0.28, P = 0.019) at the 10-y follow-up compared to the control group subjects, while no differences were detected in the prevalence of obesity between the two groups. The findings of the current study indicate that the beneficial effects of the programme on pupils' BMI continue, to an extent, 4 years after its cessation. However, the lack of significant differences in the prevalence of overweight between the two groups indicates that the effects of the intervention may not be equally distributed in the population, with greater effects in certain subgroups and less or none in others.