Watching too much TV during childhood has been linked to a higher risk of metabolic syndrome in adulthood, according to a study that spans 50 years.
Metabolic syndrome is a cluster of three or more conditions, such as excess body fat, high blood pressure, high blood sugar, and abnormal cholesterol levels, that increase the risk of heart disease, diabetes, and stroke.
The study by the University of Otago, published on July 24 in Pediatrics, found those who spent more time watching television and using screens between the ages of 5 and 15 had higher blood pressure, higher rates of obesity, less sufficient oxygen use while exercising, and other risk factors for metabolic syndrome by the time they turned 45.
“Those who watched the most had a higher risk of metabolic syndrome in adulthood,” said Dr. Box Hancox, lead researcher and professor, in a news release. “More childhood television viewing time was also associated with a higher risk of overweight and obesity and lower physical fitness.”
Researchers used data from more than 800 individuals born in Dunedin, New Zealand, in 1972 and 1973. Television viewing times were reported every two years from ages 5 to 15 and then again at 32.
On average, the participants watched just over two hours of television per weekday. Males watched slightly more TV and had a higher incidence of metabolic syndrome than females. However, researchers say the link between watching TV and metabolic syndrome may be stronger in women.
“Our finding that the association between young people’s television viewing and the later risk for metabolic syndrome was independent of adult viewing also indicates that there may be a sensitive period during childhood when excessive television viewing has a long-lasting influence on adult health,” the study authors wrote.
Moreover, very little evidence suggests that watching less TV as an adult helps reduce the association between childhood television viewing and adult health.
“Television viewing has low energy expenditure and could displace physical activity and reduce sleep quality,” Dr. Hancox explains. “Screen time may also promote higher energy intake, with children consuming more sugar-sweetened beverages and high-fat dietary products with fewer fruit and vegetables. These habits may persist into adulthood.”
Researchers suggest reducing screen time for children and young people may have long-lasting health benefits.
In a separate study published in November 2021 in JAMA Pediatrics, researchers found that higher screen times in adolescents were associated with physical and mental health risks, while more social support and better coping behaviors were associated with a lower total screen time.
The study focused on recreational activities like streaming, gaming, social media, texting, video chatting, and surfing the web.
More than 5,400 adolescents between the ages of 10 and 14 were asked about their screen-time habits. Researchers found that children spent an average of 7.7 hours a day in front of a screen.
“As screen time increased, so did adolescents’ worry and stress, while their coping abilities declined,” says study author Jason Nagata at the University of California, San Francisco, in a press release. “Though social media and video chat can foster social connection and support, we found that most of the adolescents’ screen use during the pandemic didn’t serve this purpose.”