New York, April 9 (Reuters): Prolonged sitting in front of the TV and lack of exercise can make you too fat, but that doesn’t mean people should smash their TV sets and start running marathons, researchers have said.
Limiting TV time to no more than 10 hours a week and moderate exercise, such as 30 minutes a day of brisk walking, can help adults and children reduce the risk they will become obese and develop diabetes, one serious disease associated with obesity.
“The findings are not a surprise to us, but it’s nice to have the scientific data showing the relationship,” said Frank Hu of the Harvard School of Public Health, whose study was published in the Journal of the American Medical Association’s special April theme issue on obesity.
“It is very important for individuals to realise that they are subjected to this hazard without really knowing it,” Hu said at a news conference in New York.
The study of 50,277 women between 1992 and 1998 found that adjusted for age, smoking, exercise levels and diet, each two-hour-per-day increment of TV was associated with a 23 per cent increase in obesity and a 14 per cent increase in the risk for type 2 diabetes.
This type of diabetes accounts for 90 per cent of all US cases and is related to insulin resistance, obesity, high cholesterol and high blood pressure.
An article published in the journal said standing or walking around at home for two hours a day was associated with a 9 per cent reduction in obesity and a 12 per cent reduction in diabetes. Each hour of brisk walking a day saw a 24 per cent reduction in obesity and 34 per cent reduction in diabetes.
“We are not talking here about running a marathon or smashing the television,” Hu said. A person with a body mass index, called BMI, (a person’s weight in kilograms divided by height in meters squared) of more than 30 is considered obese. “The more time spent in front of the TV, the higher the BMI,” Hu said.
The researchers said long hours of watching TV was also associated with obesity in children. In a separate commentary, obesity expert Dr Susan Yanovski of the National Institutes of Health told reporters that the proportion of children and adolescents who are overweight has tripled since the 1960s and was a worldwide problem.
Obesity had been found to predispose children and adolescents to medical complications found in adults, including hypertension, type 2 diabetes, liver disorders and sleep apnea, she said.