In a study exploring the relationship between excessive TV exposure and overweight risk for preschool-age children, researchers at the University of Michigan Health System found that 3-year-old children exposed to two or more hours of TV a day were nearly three times more likely to be overweight than children who either watched or were in a room with a TV on for fewer than two hours a day, regardless of the child’s environment at home.
These findings, published in the April issue of the Archives of Pediatric and Adolescent Medicine, also reveal than one in four 3-year-old children are exposed to five or more hours of TV a day, far surpassing the American Academy of Pediatrics’ recommendation that TV and other media exposure for children ages 2 and older be limited to less than two hours a day.
In a typical American home, the TV is on more than seven hours a day, with most children spending more time watching TV than in school – and that balance could be to blame for children’s expanding waistlines, says study lead author Julie C. Lumeng, M.D., assistant research scientist at the U-M Center for Human Growth and Development.
“Television viewing for preschool-age children appears to be a powerful predictor of overweight risk,” says Lumeng, assistant professor in the Department of Pediatrics and Communicable Diseases at the U-M Medical School. “Even if a child comes from a two-parent, upper-class home and the TV being watched is considered educational, that child is still at a higher risk for being overweight than a child who watches fewer than two hours of TV a day.”
In a previous study, Lumeng had found that children with more behavior problems are more likely to become overweight. Likewise, research also has shown that children who watch excessive amounts of TV have more behavioral problems.
From her clinical practice, too, Lumeng knew that children from low-income backgrounds or those who have a lot of stress at home watch more TV and are more likely to be overweight.
Based on these findings, Lumeng felt there could be a connection between excessive TV exposure and a preschool-age child’s likelihood for being overweight.
For the study, Lumeng and her colleagues looked at 1,016 children at ages 3 and 4 ˝.
These children, along with their parents, were enrolled in the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development, a longitudinal child care study designed to determine how variations in child care are related to children's development. The NICHD Study of Early Child Care and Youth Development provided a sample for the U-M study that was representative of both urban and rural areas in the United States.
The children in the study were classed as overweight if their body mass index (BMI) was at or above the 95th percentile. TV exposure – defined as being awake in a room when the TV is on whether or not the child was actively watching, and included broadcast and cable TV as well as videos – was determined based on a questionnaire completed by the children’s mothers.
The researchers were able to see the clear links between the amount of hours a child was exposed to TV and their potential to be overweight.
At 3 years old, children were three times more likely to be overweight if they were exposed to two or more hours of TV a day, and 25 percent watched more than five hours of TV daily.
By age 4 ˝, children with excessive exposure to TV were nearly three times more likely to be overweight than those with less TV exposure. While programming – whether it was an educational show or not – did not impact a child’s overweight risk, Lumeng says excessive exposure to advertising on TV for unhealthy foods and the likelihood that a child may snack while watching TV may be contributing factors to weight gain.
Additionally, children who watched two or more hours of TV a day had more behavior problems. They also were more likely to have mothers with more depressive symptoms and a less stimulating home environment. Regardless of the child’s overall quality of their home environment, Lumeng says TV exposure should be considered an independent risk factor for overweight risk in preschool-age children.
“Parents should consider how much time the TV is simply on, not just the time the child actually spends watching it. Our findings suggest the exposing children to TV even as background noise may increase their overweight risk,” notes Lumeng. “Simply put, families should try to reduce the amount of time the TV is on in their homes. Reduced TV time is beneficial for everyone.”
Along with Lumeng, co-authors are Sahand Rahnama, BS, and Niko Kaciroti, Ph.D., of the U-M Center for Human Growth and Development; Danielle Appugliese, MPH, Boston University; and Robert H. Bradley, Ph.D., University of Arkansas at Little Rock.
The study was funded by the American Heart Association in Dallas, through its Fellow-to-Faculty Transition Award and the Midwest Affiliate Grant-in-Aid.