Decrease in television viewing predicts lower body mass index at 1-year follow-up in adolescents, but not adults.

Objective: To examine associations between television viewing, sugar-sweetened beverage consumption, eating out, physical activity, and body weight change over 1 year.

Design: Secondary data analysis from randomized intervention trial.

Setting: Households in the community.

Participants: Adults (n = 153) and adolescents (n = 72) from the same households.

Intervention: Households were randomized to a home-based obesity prevention intervention or to a no-intervention control group for a 1-year period.

Main Outcome Measures: Self-reported television viewing (TV) hours, diet, and physical activity. Body mass index (BMI) computed from measured weight and height (primary outcome measure).

Analysis: Mixed-model regression.

Results: Among adolescents, a significant prospective association was observed between decreases in television viewing hours and lower BMI z score at 1-year follow-up (decreased TV hours: BMI z score mean = 0.65; no change or increase TV hours: BMI z score = 0.92; P < .02). No significant prospective associations were observed among adults.

Conclusions And Implications: Reducing television viewing may be an effective strategy to prevent excess weight gain among adolescents.