Washington :The more hours young adults spend watching TV each day, the more likely they are to have a higher body mass index (BMI) and bigger waist circumference five years later, a 15-year analysis has found.
The association, however, did not hold for the middle-aged, indicating that young adulthood is an important time to intervene and promote less television viewing.
“We were quite surprised to find that television viewing was associated with subsequent obesity for young adults, but not for the middle-aged,” said lead author Anthony Fabio, assistant professor of epidemiology at University of Pittsburgh Graduate School of Public Health in US.
“This suggests that middle-aged adults may differ from young adults in how they respond to the influence of TV viewing,” Fabio said.
Fabio and his colleagues analysed data from 3,269 adults recruited from Birmingham, Chicago, Minneapolis, and Oakland, who participated in the Coronary Artery Risk Development in Young Adults (CARDIA) Study.
For 15 years starting in 1990, the participants reported their television viewing habits and had their waist circumference measured and their BMI (a measure of weight and height that can indicate obesity) calculated every five years.
The more time participants spent watching television when they were approximately 30 years old, the more likely they were to be obese five years later, compared to their peers who spent less time in front of the television. The team did not have data on younger ages.
Fabio and his team suspect many potential reasons for the association, including that young adults may be more likely to snack during television viewing and consume unhealthy food due to their greater susceptibility to the seduction of junk food advertising on television.
In support of that hypothesis, the study also found that participants were more likely to eat healthier foods as they aged.
The analysis found that 23 per cent of the men and 20.6 per cent of the women participating in the study watched four or more hours of television daily.
Within that group of heavy TV watchers, 35.9 per cent were black, and 8.6 per cent were white; and 40.8 per cent had a high school education or less, versus 17.4 per cent with an education beyond high school.
A lower family income and higher rates of smoking and drinking also were associated with more time spent watching television.
The study was published in the journal SAGE Open.