More than two hours of TV viewing per day increased risk of type 2 diabetes and cardiovascular disease, and more than three hours of daily viewing increased risk of premature death, according to the study by Harvard School of Public Health (HSPH) researchers.
For additional two hours of viewing per day, the risk of type 2 diabetes increased by 20 per cent, that of cardiovascular disease by 15 per cent and premature death by 13 per cent.
“The message is simple. Cutting back on TV viewing can significantly reduce risk of type 2 diabetes, heart disease and premature mortality,” senior author Frank Hu, professor of nutrition and epidemiology at HSPH said.
“We should not only promote increasing physical activity levels but also reduce sedentary behaviours, especially prolonged TV watching,” Hu said.
Most people around the world divide their day largely between work, sleep and watching television, according to the researchers.
Europeans and Australians spend about 3—4 hours watching TV while Americans spend an average of five hours infront the idiot box.
They estimated that among 100,000 individuals per year in US, each 2—hour increment in television viewing per day was associated with 176 new cases of type 2 diabetes, 38 new cases of fatal cardiovascular disease and 104 new cases of all—cause mortality.
Hu and author Anders Grontved, a visiting researcher in the HSPH Department of Nutrition, conducted systematic assessment of all published studies from 1970 to 2011 that linked TV viewing with increased risk of type 2 diabetes, cardiovascular disease and premature death.
“Sedentary lifestyle, especially prolonged TV watching, is clearly an important and modifiable risk factor for type 2 diabetes and cardiovascular disease,” said Grontved.
They found that the effect of prolonged television viewing on type 2 diabetes, which usually occurs in adults, to some extent explains the unfavourable influence of TV viewing on obesity.