Reducing TV watching during adult obesity treatment: two pilot randomized controlled trials.

The more time adults spend being sedentary, the greater the risk of obesity. The effect of reducing television (TV) watching, a prominent sedentary behavior, on weight loss has not been tested in an adult standard behavioral obesity intervention, and the mechanisms by which reducing TV watching influences energy balance behaviors are not well understood. Two, 8-week, pilot, randomized controlled trials were conducted examining the effect of a reduced TV watching prescription on energy balance behaviors and weight loss within an adult standard behavioral obesity intervention. In the first study, participants (n=24) were randomized into one of two conditions: (a) reduce energy intake and increase moderate to vigorous physical activity (MVPA) (INCREASE PA); or (b) reduce energy intake and decrease TV watching (DECREASE TV). As findings from the first pilot study did not show an increase in MVPA in the DECREASE TV group, the second study was designed to examine the effect of adding a reduced TV prescription to a standard intervention to optimize outcomes. In Pilot Study 2, participants (n=28) were randomized to INCREASE PA or to INCREASE PA+DECREASE TV. Outcomes included objectively measured TV watching and MVPA, self-reported light physical activity (LPA-Pilot Study 2 only), self-reported dietary intake while watching TV, and weight. Conditions with TV watching prescriptions significantly reduced TV watching. Both studies showed medium to large effect sizes for conditions with TV watching prescriptions to show greater reductions in dietary intake while watching TV. Pilot Study 1 found a trend for an increase in MVPA in INCREASE PA and Pilot Study 2 found significant increases in MVPA in both conditions. Pilot Study 2 found a significant increase in LPA in the INCREASE PA+DECREASE TV. Results indicate adding a TV watching prescription to a standard obesity intervention did not enhance increases in MVPA, but may assist with reducing dietary intake while TV watching and increasing LPA. Future research should examine the effect of reducing TV watching during obesity treatment over a longer time frame in a larger sample.