Mediators of Longitudinal Changes in Measures of Adiposity in Teenagers Using Parallel Process Latent Growth Modeling

Objective: The aim of the study was to evaluate mediating effects of energy balance-related behaviors on measures of adiposity in the Dutch Obesity Intervention in Teenagers-study (DOiT). Design and Methods: DOiT was an 8-month behavioral intervention program consisting of educational and environmental components and evaluated in 18 prevocational secondary schools in the Netherlands (n=1,108, baseline age 12.7 years, 50% girls). Outcome measures were changes in body mass index (BMI), waist circumference, and sum of skinfold thickness. Self-reported consumption of sugar-containing beverages and high caloric snacks, active transport to/from school, and screen-viewing behaviors were the hypothesized mediators. Data were collected at 0, 8, 12, and 20 months. For the data analysis, parallel process latent growth modeling was used. Results: Total sugar-containing beverages consumption mediated the intervention effects on BMI (ab=-0.01, 95% CI=-0.20, -0.001). The intervention group lowered their sugar-containing beverages consumption more than controls (B=-0.14, 95% CI=-0.22, -0.11) and this, in turn, led to smaller increases in BMI. No significant mediated effect by the targeted behaviors was found for waist circumference or sum of skinfolds. Conclusions: Future school-based overweight prevention interventions may target decreasing sugar-containing beverages consumption.