UVM Theses and Dissertations
Format:
Print
Author:
Otten, Jennifer J.
Dept./Program:
Animal, Nutrition and Food Sciences Program
Year:
2009
Degree:
Ph. D.
Abstract:
Context: The average adult watches almost 5 hours oftelevision (TV) per day, an amount associated with increased risks for obesity. Research in children has shown that interventions focused on TV reduction can improve body weight, body composition, and d;ecrease energy intake. The effect of TV reduction in adults is not known. Objective: To examine the effects of reducing TV viewing time on energy intake, energy expenditure, energy balance, body mass index (BMI), and sleep in overweight and obese adults.
Design and Participants: Randomized controlled trial of 36 healthy adults with a BMI of 25-50 kg/m² who self-reported a minimum of 3 hours/day of TV viewing. Subjects participated in home-based protocols from January through July 2008. After a 3 week observation phase, subjects were stratified by BMI and randomized to observation-only control (n=16) or intervention group (n=20) for 3 additional weeks. Intervention: TV viewing time reduced by 50% of each subjects' objectively measured baseline enforced by an electronic lock-out system. Main Outcome Measures: Change in energy intake, energy expenditure, energy balance, BMI, and sleep.
Results: Both groups reducecdrenergy intake ( -125 kcal/day [95%CI, -303, 52] vs.-38 [95%CI, -265, 190] for intervention and control subjects, respectively) with no effect of intervention (P=.52). Intervention Intervention subjects significantly increased energy expenditure (119 kcal/day [95%CI, 23, 215] compared to controls ( -95 kcal/day [95%CI, -254, 65]) (P=.02). Energy balance was negative in the intervention group between phases [-244 kcal/day [95%CI, -459, -30] but positive in controls (57 kcal/day [95%CI, -216, 330]) (P=.07). BMI showed a greater reduction in the intervention group ( -0.25 kglm2 [95%CI, -0.45, -0.05] vs.-0.06 [95%CI, -0.43, 0.31] in controls, P=.33). There was no change in sleep.
Conclusions: After three weeks, a TV reduction intervention in overweight and obese adults produced no change mienergy intake or sleep, a significant increase in energy expenditure, and a trend toward negative energy balance. BMI change, while not significant, showed greater reduction in the intervention group and thus was in a direction consistent with other, measured outcomes. To our knowledge, this is the first study to measure the effects of a TV reduction intervention in adults. Reducing TV viewing should be further explored as a method to reduce and prevent obesity in adults.
Design and Participants: Randomized controlled trial of 36 healthy adults with a BMI of 25-50 kg/m² who self-reported a minimum of 3 hours/day of TV viewing. Subjects participated in home-based protocols from January through July 2008. After a 3 week observation phase, subjects were stratified by BMI and randomized to observation-only control (n=16) or intervention group (n=20) for 3 additional weeks. Intervention: TV viewing time reduced by 50% of each subjects' objectively measured baseline enforced by an electronic lock-out system. Main Outcome Measures: Change in energy intake, energy expenditure, energy balance, BMI, and sleep.
Results: Both groups reducecdrenergy intake ( -125 kcal/day [95%CI, -303, 52] vs.-38 [95%CI, -265, 190] for intervention and control subjects, respectively) with no effect of intervention (P=.52). Intervention Intervention subjects significantly increased energy expenditure (119 kcal/day [95%CI, 23, 215] compared to controls ( -95 kcal/day [95%CI, -254, 65]) (P=.02). Energy balance was negative in the intervention group between phases [-244 kcal/day [95%CI, -459, -30] but positive in controls (57 kcal/day [95%CI, -216, 330]) (P=.07). BMI showed a greater reduction in the intervention group ( -0.25 kglm2 [95%CI, -0.45, -0.05] vs.-0.06 [95%CI, -0.43, 0.31] in controls, P=.33). There was no change in sleep.
Conclusions: After three weeks, a TV reduction intervention in overweight and obese adults produced no change mienergy intake or sleep, a significant increase in energy expenditure, and a trend toward negative energy balance. BMI change, while not significant, showed greater reduction in the intervention group and thus was in a direction consistent with other, measured outcomes. To our knowledge, this is the first study to measure the effects of a TV reduction intervention in adults. Reducing TV viewing should be further explored as a method to reduce and prevent obesity in adults.