Association between a school-based intervention and adiposity outcomes in adolescents: The Italian "EAT" project.

Objective: To evaluate whether a school-based multicomponent educational program could improve adiposity measures in middle-school adolescents.

Methods: A non-randomized controlled pilot study was conducted in six state middle schools (487 adolescents, 11-15 years) in townships in an urban area around Milan, three schools (n = 262 adolescents) being assigned to the intervention group and three schools (n = 225 adolescents) to the control group. The two-school-year intervention included changes in the school environment (alternative healthy vending machines, educational posters) and individual reinforcement tools (school lessons, textbook, text messages, pedometers, re-usable water bottles). The main outcome measure was change in BMI z-score. The secondary outcomes were changes in waist-to-height ratio (WHtR) and behavioral habits.

Results: The intervention was associated with a significant difference in BMI z-score (-0.18 ± 0.03, P<0.01) and in WHtR (-0.04 ± 0.002, P < 0.001), after controlling for baseline covariates. Subgroup analysis showed the maximum association between the intervention and the difference in BMI z-score for girls with overweight/obesity. Physical activity increased and consumption of sugar-sweetened beverages and high-energy snacks decreased in adolescents after the intervention.

Conclusions: A school-based multicomponent intervention conducted at both environmental and individual levels may be effective for reducing adiposity measures mainly in adolescents with overweight/obesity.