The amount of time children ages 2-4 spend watching television on a daily basis appears to be negatively correlated with their levels of fitness and weight in elementary school, according to a study published online Sunday in the International Journal of Behavioral Nutrition.
Specifically, every extra hour of television a 29-month-old child watches per week was linked to a decrease in lower-body muscular strength in elementary school, the study found.
The American Academy of Pediatrics discourages media usage for children to 2, saying that "media—both foreground and background—have potentially negative effects and no known positive effects for children younger than 2 years." For children older than 2, the AAP recommends limiting their media-usage time to no more than 1-2 hours of quality programming per day.
Researchers from the Université de Montréal, Canada, examined data from 2,120 children taken from the Quebec Longitudinal Study of Child Development to examine the effects of toddlers' television watching on their waistline later in childhood.
When the children were 29 and 53 months old, their parents were asked how much time the child spent watching television on a daily basis. Once each child reached elementary school, he or she took part in a standing-long-jump exercise in both 2nd and 4th grades to measure lower-body strength, which correlates with overall fitness. Each child's waist circumference was measured by trainers in 2nd and 4th grades with measuring tape, as well.
For parents who use television as an "electronic babysitter" for their children, the researchers' findings may cause some dismay.
For every extra hour of weekly television a child watched between 29 months and 53 months, the child showed a .047 centimeter increase in waist circumference by the 4th grade. Similarly, each extra hour of weekly television watching resulted in a decrease of .285 cm in the standing-long-jump test by the 2nd grade.
"Our findings suggest that early-childhood viewing may also undermine future explosive leg strength and contribute to the accumulation of abdominal fat," the researchers write.
The researchers discovered that children at 29 months averaged 8.82 hours of television watching per week, increasing to an average of 14.85 hours per week by 53 months. Based on the 8.82 hours per-week level, the researchers would predict an increase of .41 cm in a child's waistline by age 10.
"TV is a modifiable lifestyle factor, and people need to be aware that toddler viewing habits may contribute to subsequent physical health," said lead researcher Caroline Fitzpatrick of New York University in a statement. "Further research will help to determine whether the amount of TV exposure is linked to any additional child-health indicators, as well as cardiovascular health."
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