According to a new Yale study, televisions in children’s bedrooms may usurp parental authority.

Researchers found that authoritative parenting reduced the level of sugary drink consumption in middle schoolers, but that this positive effect was not as strong when there was a television in the child’s bedroom. In other words, given equally strict parenting styles, children with televisions in their rooms tended to consume greater quantities of sugary drinks than those without a television. The reason, researchers said, is likely the influence of sugary drink advertisements on the children watching them. The research could point to further initiatives educating parents about the risk of placing TVs in children’s bedrooms.

“It has been known for a while that having a TV in the bedroom is associated with higher rates of childhood obesity,” said Marlene Schwartz, director of the Rudd Center for Food Policy and Obesity at the University of Connecticut, stressing that many parents try to teach their children to avoid unhealthy sugary drinks, but that children still end up consuming lots of sodas, juices and sports drinks. “We wanted to see if one way that having a TV in the bedroom hurt children was by exposing children to marketing for unhealthy drinks, and effectively undoing the messages that their parents were trying to give them.”

Researchers recruited 480 children from 12 different low-income schools. Children took surveys assessing their parents’ nurturing and controlling behaviors, whether or not the children had televisions in their rooms and their level of sugary drink consumption the previous day. Using the responses about parental behavior, researchers crafted an “authoritative parenting” score. They then used regression analyses to detect the interactions between that score and the presence of a television on children’s sugary drink consumption. Sure enough, higher authoritative parenting scores predicted lower sugary drink consumption, but that effect was reduced when children had televisions in their rooms.

Past results have shown that sugary drinks are particularly harmful to health — liquid sugar affects the body differently than the same amount of sugar in the form of food, Schwartz said. For example, someone eating 100 calories worth of jelly beans would eat less food later in the day than someone who has consumed the same amount in liquid calories. In other words, the body does not seem to properly recognize calories consumed in liquid sugar, leading to overeating and the myriad health issues associated with excess body fat.

During middle school, dietary habits begin to solidify, meaning that the ways children eat during these years are likely to become life-long patterns. Thus, reducing sugary drink consumption in sixth and seventh graders is a high priority. Schwartz noted that stricter parents may feel the need to pick their battles carefully — for example, a parent who frequently checks that the child has completed homework and regulates how often the child is allowed to go out may feel that allowing a television in the bedroom is not an important point to argue over. This study shows that the television’s implications extend into many spheres of children’s wellbeing, and, as a parent, is not worth compromising on, she said.

Schwartz also noted that it may not just be televisions that hurt the positive effects of authoritative parenting — with increasing access to smartphones and computers, children may be exposed to harmful advertising even without a television in the room. The data came exclusively from low-income families, and thus may not be as applicable to families in a higher income bracket. Still, she stressed that “we need to find stronger ways to communicate with parents about the harm of sugary drinks, the harm of food marketing and the harm in allowing your child to have a TV” in the bedroom.

The study was funded by the National Institute of Child and Human Development, the Patrick and Catherine Weldon Donaghue Medical Research Foundation and the Rudd Foundation, which funds the Rudd Center.