Try Turning Off the Television

You're all no doubt more than familiar with the two main strategies for weight loss: reducing the number of calories you eat and increasing the number of calories you burn. Obesity researchers are also looking at ways to decrease the amount of time people spend in sedentary behaviors (activities that don't significantly increase the number of calories you burn much above your baseline resting state). Sedentary behaviors alone, even if you meet the recommended levels of exercise, are still linked to greater risks of obesity and metabolic syndrome.

One major sedentary behavior is television watching. In fact, according to Neilsen Inc. the average American adult watches television for almost 5 hours per day. Not only is it sedentary, but we also know that distractions while you are eating, such as television, lead to eating more and weighing more (News Bite 11/07/06). Researchers at the University of Vermont devised a study to find out if reducing the amount of television a person watched would actually reduce their caloric intake or their weight (Arch Intern Med 2009;169(22):2109-2115).

The researchers recruited 36 people to participate in their study. The subjects were all between the ages of 21 and 65, had a Body Mass Index of 25 to 50 (clinically overweight to obese), and who reported watching between 3 and 8 hours of television per day.

The study itself was in two parts. The initial three-week phase was used to set baselines: first each subject was weighed and their Body Mass Index calculated. Then in each participants' home, the study staff installed a monitor on the television unit. The participant entered a unique code on the unit to turn the television on, allowing the study staff to accurately measure when the participant was watching television. During this initial phase the participants were also taught to maintain diet logs and sleep logs. In the third week of the first phase the participants also wore armbands that estimated the calories they burned.

In the second three-week phase of the study, the participants were randomly assigned to either a control group or a study group. The control group continued with their daily lives as in the first phase of the study, including the energy measurement in week three. The study group also maintained their diet and sleep logs and wore the armbands in the third week, but they had their weekly television viewing reduced by half: the monitor unit turned the television off automatically once it had been on for half of the time it was on in the first phase of the study.

At the close of the second three weeks, the participants were again weighed and their Body Mass Index calculated. The researchers also compared the two groups' diet and sleep logs and the amount of calories each person burned as compared to the baseline three weeks.

They found that those who had their television viewing reduced by half ate about 125 calories per day, on average, less than they had during phase 1. (Those whose television viewing was not reduced ate about 38 calories less.) The study group also burned an extra 119 calories per day, on average, than they had during phase 1, while the control group actually burned 95 fewer calories than they had in the initial phase.

What this means for you

While the difference between the number of calories the two groups ate is not considered "clinically significant," what's important is that eating 125 fewer calories and burning an extra 119 calories each day was enough that those who watched less television lost an average of 1.5 pounds in the three weeks of the test period. If you're working on your weight, add watching less television to your strategies of eating less and moving more. Every little bit helps!

First posted: December 16, 2009