Objective: To determine whether a multicomponent health promotion intervention for Dutch adolescents (defined as persons between 12 and 14 years of age) would be successful in influencing body composition and dietary and physical activity behavior in both the short and long terms.
Design: Randomized controlled trial.
Setting: Ten intervention and 8 control prevocational secondary schools.
Participants: A total of 1108 adolescents (mean age, 12.7 years). Intervention An interdisciplinary program with an adapted curriculum for 11 lessons in biology and physical education and environmental change options.
Main outcome measures: Body height and weight, waist circumference, 4 skinfold thickness measurements, and dietary and physical activity behavior data.
Results: Multilevel analyses showed that the intervention remained effective in preventing unfavorable increases in important measures of body composition after 20-month follow-up in girls (biceps skinfold and sum of 4 skinfolds) and boys (triceps, biceps, and subscapular skinfolds). Consumption of sugar-containing beverages was significantly lower in intervention schools both after intervention (boys: -287 mL/d; 95% confidence interval [CI], -527 to -47; girls: -249; -400 to -98) and at 12-month follow-up (boys: -233; -371 to -95; girls: -271; -390 to -153). For boys, screen-viewing behavior was significantly lower in the intervention group after 20 months (-25 min/d; 95% CI, -50 to -0.3). No significant intervention effects on consumption of snacks or active commuting to school were found.
Conclusion: The Dutch Obesity Intervention in Teenagers program resulted in beneficial effects on the sum of skinfold thickness measurements in girls and consumption of sugar-containing beverages in both boys and girls in both the short and long terms.