Comparison of two school-based programmes for health behaviour change: the Belo Horizonte Heart Study randomized trial.

OBJECTIVE To assess the efficacy of two school-based programmes to promote students' willingness to engage in lifestyle changes related to eating habits and physical activity behaviours. DESIGN Elementary school-based health promotion intervention, designed as a multicomponent experimental study, based on a behavioural epidemiological model. SETTING Nine intervention and eight comparative public and private elementary schools. SUBJECTS The goal was to determine the impact on the longitudinally assessed outcomes of two programmes that addressed healthy nutrition and active living in a cohort of 2038 children. The evaluations used pre-intervention and follow-up student surveys that were based on the Transtheoretical Model of the stages of behaviour change. RESULTS In the intervention group, there were significant (P < 0·001) differences between the pre- and post-intervention times in the stages of change, with a reduction in the percentage of children at the pre-contemplation and contemplation stages and increased percentages at the preparation, action and maintenance stages, leading to healthier behaviours in fatty food consumption, fruit and vegetable consumption, physical activity and time spent in sedentary activities. The determinants of the behaviour stage were the intervention programme, the type of school and the presence of motivated teachers. The comparison group did not show significant differences between the pre- and post-intervention times for any of the stages of behaviour. CONCLUSIONS The intervention programme encouraged the students to make healthy lifestyle choices related to eating habits and physical activity behaviours.