As per the background information of a new study, an average adult watches almost five hours of TV and cutting the time by half helps to burn calories.
The study used an electronic lock-out system to reduce the television time by half without changing the calorie intake.
However, it was found more energy was spent over a three-week period.
Jennifer J. Otten, Ph.D., R.D., then of the University of Vermont, Burlington, and now of Stanford University School of Medicine, Palo Alto, Calif., and colleagues conducted a randomized controlled trial of 36 adults who had a body mass index between 25 and 50 and reported watching at least three hours of TV per day.
Between January and July 2008, 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.
It was found that those with the lock-out systems burned 119 more calories per day during the three-week period, while the control group burned 95 fewer calories per day during the intervention than during the observation period.
Also, Energy balance-the comparison of calories consumed to calories burned-was negative in the intervention group (who consumed 244 calories less than they burned each day) but positive in the control group (who consumed 57 more calories than they burned each day); however, this difference did not reach statistical significance.
The authors wrote: "A recent task force report supports small behavior changes as a more sustainable, long-term approach to help address the obesity epidemic.
"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."
In the past it has been found in children that screen time reductions reduce calories consumed but do not increase calories burned.
The authors concluded: "This suggests that adults may differ from children in how they respond to reductions in sedentary behaviors.
"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."
The study has been published in December 14/28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.