"Competitive" Food and Beverage Laws and Obesity Among Diverse Youth in California High Schools.

Purpose: To investigate associations between the California "competitive" food and beverage (CF&B) laws and overweight/obesity (OV/OB) among high school youth by gender, school-neighborhood income, and race/ethnicity, and to examine racial/ethnic OV/OB disparities before and after CF&B policies.

Methods: Using an interrupted time series design paired with retrospective cross-sectional Fitnessgram data from 3,565,260 youth-level records on ninth-grade students in California public schools, we estimated gender, school-neighborhood income, and racial/ethnic OV/OB prevalence trends before (2002-2007) and after the CF&B policies were in effect (2008-2012).

Results: In the period before the CF&B policies, OV/OB prevalence increased annually among the majority of subgroups regardless of gender, school-neighborhood income and race/ethnicity. In the period after the policies took place, OV/OB increased at a slower rate, plateaued or declined. Changes in log odds of OV/OB trends ranged from -0.03 to -0.07. In the period before the CF&B policies, OV/OB disparities widened between African American and Latino versus White males within each school-neighborhood income tertile; afterwards, disparities ceased to increase or slightly narrowed.

Discussion: The California CF&B laws for high schools are associated with favorable trends in youth OV/OB. This is the first study to examine these associations among multiple socio-demographically diverse high school youth simultaneously considering gender, school-neighborhood income and race/ethnicity. The degree to which observed changes in OV/OB trends are attributable to CF&B policies is unclear. Nevertheless, the results suggest that strengthening CF&B policies may help further reduce OV/OB among youth of different genders and ethnicities in schools across neighborhoods of varying income levels.