Still Overweight? Switch Off the TV

Apparently the average US adult watches TV for almost 5 hours a day.  Suppose one measured the benefits of cutting the viewing hours?  A study done at the University of Vermont aimed to find out; the findings are published in the Archives of Internal Medicine. 

Thirty-five adults with a body mass index (BMI) over 25 – i.e. anything from overweight to very obese – who reported a minimum of 3 hours TV-viewing daily were enrolled.  After a 3-week observation period, they were grouped according to their BMI level and then randomly assigned to either an observation-only group, or an ‘intervention’ group, for 3 weeks.  The intervention consisted of reducing their TV viewing by 50%; this was achieved by an electronic lock-out set to 50% of each individual’s normal daily viewing period.

Both groups reduced their calorie intake, though more so in the intervention group.  The intervention group increased their energy expenditure significantly, compared with the controls, so their energy balance was negative during the experimental phase (compared with the observation phase), while the control group’s energy balance was slightly increased.  The average BMI was reduced more in the intervention group than in the controls. 

These results demonstrate exactly what one would expect – switching off the TV results in greater energy expenditure (doing something active, instead of just sitting) and thus some weight loss.  As if we didn’t know that already!