Previous studies have shown that poor TV viewing habits during childhood carry on into adulthood, leading to obesity and elevated total cholesterol. According to the study's authors, the average U.S. child from age 8 to 18 watched 4.5 hours of TV each day, and 70% of them have a TV in their bedroom. Around 1/3 of Americans from age 6 to 19 are considered obese.
"The established association between TV and obesity is predominantly based on BMI," said Dr. Peter Katzmarzyk, lead investigator on the study. "The association between TV and fat mass, adiposity stored in specific depots (including abdominal subcutaneous and visceral adipose tissue), and cardiometabolic risk, is less well understood. It is hypothesized that higher levels of TV viewing and the presence of a TV in the bedroom are associated with depot-specific adiposity and cardiometabolic risk."
The study looked at 369 Baton Rouge children aged 5 to 18 from 2010 to 2011. The kids' waist circumference, resting blood pressure, fasting triglycerides, "bad" cholesterol, glucose, fat mass, and stomach fat were all measured.
The results showed not only that children with a TV in their bedroom were likely to watch more TV, but they also had more fat and a higher waist circumference than children who did not. Kids with a TV in the bedroom were three times more likely to have an elevated heart and metabolic risk; elevated waist circumference; and elevated triglycerides.
"There was a stronger association between having a TV in the bedroom versus TV viewing time, with the adiposity and health outcomes," said Dr. Amanda Staiano, co-author of the study. "A bedroom TV may create additional disruptions to healthy habits, above and beyond regular TV viewing. For instance, having a bedroom TV is related to lower amounts of sleep and lower prevalence of regular family meals, independent of total TV viewing time. Both short sleep duration and lack of regular family meals have been related to weight gain and obesity."