Less TV Could Help You Burn Calories

(December 16, 2009) - If you want to get more exercise, then turn off the TV. (Read about "Getting Started on Fitness") Adults who used an electronic lock-out system to reduce their television time by half did not change their calorie intake but did expend more energy over a three-week period, according to a report in the Archives of Internal Medicine, one of the JAMA/Archives journals.

The average adult watches almost five hours of television per day, according to background information in the article. Some efforts to prevent and reduce obesity (Read about "Obesity") have focused on modifying diet and physical activity, but newer strategies have involved reducing sedentary behaviors such as TV watching. Not only may reducing TV time allow time for more active endeavors, it may also help alleviate chronic sleep deprivation (Read about "Sleep"), potentially linked to obesity.

Researchers conducted a randomized controlled trial of 36 adults who had a body mass index (Read about "Body Mass Index") between 25 and 50 and reported watching at least three hours of TV per day. All participants underwent a three-week observation period during which their daily TV time was assessed. A group of 20 individuals was then randomly assigned to receive an electronic device that shut off the TV after they had reached a weekly limit of 50 percent of their previously measured TV viewing time. An additional 16 participants served as a control group.

Those with the lock-out systems burned 119 more calories per day during the three-week period. In comparison, the control group burned 95 fewer calories per day during the intervention than during the observation period. Energy balance - energy intake minus energy expenditure - was negative in the intervention group (by 244 calories per day) but positive in the control group (by 57 calories each day); however, this difference did not reach statistical significance.

"A recent task force report supports small behavior changes as a more sustainable, long-term approach to help address the obesity epidemic," the authors write. "It has been estimated that combined increases in energy expenditure and decreases in energy intake equaling only 100 calories per day could prevent the gradual weight gain observed in most of the population."