Why Does TV Make You Fat?

The couch potato stereotype might not be so far off-base. According to a 2008 study published in the American Journal of Clinical Nutrition, people who watch more than three hours of TV a day are more likely to carry extra inches around the midsection than those who watch an hour a day or less.

Television And Belly Fat : The Study

2001 Australian adults between 26 and 36 participated in this study. The participants had their waistlines measured at study clinics and were asked to provide other information: TV viewing time, what they ate and drank while watching TV, demographics and what physical activities they did in their spare time.

The study found that watching more than three hours of TV a day is associated with a higher likelihood of severe abdominal obesity in women and moderate abdominal obesity in men. Participating in physical activity for fun didn’t have any effect on this relationship.

The researchers had two explanations for these results:

1. Reduced physical activity in participants’ spare time

2. Increased eating and drinking during TV watching.

Exercising Less
Sedentary leisure activities like watching TV are often blamed for increasing rates of obesity. Other reliable studies have found that adults who watch the most TV are 2.4 times more at risk for obesity than those who watch the least TV. The average Australian adult spends an average of almost two hours a day watching TV.

One theory was that watching so much TV during spare time might take away from opportunities for calorie-blasting physical activity. When the researchers accounted for free time spent in recreational physical activities, though, there wasn’t a significant difference between those who did exercise and those who didn’t. The study concluded that spending less time in physical activity isn’t responsible for the increased risk of obesity. Taking in more calories was a stronger influence.

Prime Time is Snack Time
The second theory was that TV viewing resulted in increased calorie consumption through advertising or snacking. Many TV advertisements feature unhealthy foods. These advertisements might have an increased influence on people who watch more TV because those viewers are exposed to more food ads. People, especially children, also tend to snack on high-calorie foods and sodas when they’re watching TV.

After testing their theory, the researchers found that eating and drinking while watching TV is strongly associated with added inches around the midsection—but only for women. The men in the study showed no relationship between obesity and snacking during TV time.

So, Why Does TV Make You Fat?
There’s a definite relationship between an increase in TV time and an increase in waist size, although it’s not fully clear why. The study ruled out reduced recreational activity as the main culprit. Extra snacking was partly to blame, at least for the women who participated, but it wasn’t fully responsible either.

Advertising’s influence wasn’t tested in this study, so the influence of junk food ads could still be a factor. Either way, the link between TV and obesity is likely behavioral, so be aware of what you’re doing when you’re watching TV.