By Val Wadas-Willingham
(CNN) -- While growing up, many children may have heard "clean your plate" or been denied candy. But how do parental attitudes toward food affect a child's weight?
Denying certain foods to children or pressuring them to eat every bit of a meal are common practices among many parents. But researchers at the University of Minnesota found parents who restricted foods were more likely to have overweight or obese children. And while those who pressured children to eat all of their meals mostly had children of normal weight, it adversely affected the way those children ate as they grew older, according to the study published Monday in the journal Pediatrics.
Investigators combined data from two separate research studies. The first, EAT 2010 (Eating and Activity in Teens), studied around 2,800 middle and high school students from public schools in Minneapolis and St. Paul, Minnesota. Participants in the project responded to survey questionnaires designed to examine dietary intake and weight status.
Researchers combined that data with information from the Project F-EAT (Families and Eating and Activity Among Teens), a study designed to examine factors within the family environment on weight in adolescents.
From the combined information, researchers were able to gain a better understanding of how parents' approach to food and feeding is related to adolescents' weight. According to the Centers for Disease Control and Prevention, obesity now affects 17% of all children and adolescents in the United States - triple the rate from just a generation ago.
"We found that between 50 and 60% of parents from our sample reported requiring that their child eat all of the food on their plate at a meal," said researcher Katie Loth, the study's lead author. "Further, we found that between 30-40% of parents from within our sample reported encouraging their child to continue eating even after their child stated that they were full.
"While these pressure-to-eat behaviors were more frequent among parents of non-overweight adolescents, they were still endorsed quite frequently by parents of overweight and obese adolescents, indicating that many parents endorse these behaviors regardless of their child's current weight status," she said.
Researchers also found dads were more likely than moms to pressure their sons and daughters to eat, and adolescent boys were pressured more than adolescent girls.
"Parental pressure to eat can be detrimental to children because it takes away from a child's ability to respond naturally to their own hunger," said Loth. "Instead, (it) encourages them to respond to cues in their environment which can lead to unhealthy weight gain over time."
The data also showed that restricting food from kids was a common practice of either parent, in both boys and girls.
"Research has shown that when a parent places a restriction on a particular food item (i.e. no treats) that a child becomes more interested in consuming that food item and will often overeat that food when given the opportunity," Loth continued. "Instead, parents should be encouraged to allow their children to eat all foods in moderation."
Investigators believe that parents should keep an eye on their child's weight and make an effort to better understand good eating practices, instead of worrying about whether their kids clean their plates or have a cookie now and then.
Study authors recommended such practices as eating regular family meals, having nutritious snacks at home, choosing healthy foods and encouraging young people to make better food choices as a way to fight weight problems, Loth said.
And most importantly, "parents should also work hard to model healthy eating and a healthy relationship with food to their child" by eating a well-balanced diet, Loth said.