TUESDAY, July 26 (HealthDay News) The obesity epidemic is being fueled still further by a growing trend among kids to eat out and bring take-out food home, University of North Carolina researchers say.

Such foods are high in sugar and calories, and their increasing popularity means youngsters are getting more calories than they need, the researchers noted.

Since 1994, this trend has been growing rapidly and reflects the availability of fast food restaurants and foods prepared in supermarkets and other food stores, the researchers say. In fact, calories eaten away from home increased from 23.4 percent to 33.9 percent between 1977 and 2006.

"We found that kids eat a relatively maintained level of calories at home, but in addition kids also eat an increasing number of calories outside the home," said study author Jennifer Poti, from the university's Gillings School of Global Public Health. "Eating outside the home is actually fueling the increased energy intake for kids."

Poti said much of the foods children eat outside the home comes from prepared meals sold in supermarkets and convenience stores, as well as fast food restaurants. Much of the fast food children eat is actually consumed at home, Poti said. In 2006, almost half of the fast foods children ate were eaten at home, she noted.

Although the reasons for this increase in eating prepared meals isn't known, Poti speculates it's a combination of factors including convenience, cost and time pressures.

This trend is adding to the obesity epidemic, Poti said. "Parents need to be interested in both the food source and location where it is eaten, which both significantly influence energy intake," she said.

The report is published in the August issue of the Journal of the American Dietetic Association.

For the study, Poti's team collected data on 29,217 children aged 2 to 18. They had taken part in either Nationwide Food Consumption Survey, the Continuing Survey of Food Intakes by Individuals or one of another two nationally representative surveys of food intake in the United States. These surveys collected data at different times between 1977 to 2006, the study noted.

The researchers found that from 1977 to 2006 the number of calories children got from foods eaten away from home increased significantly. In fact, the percentage of calories children got from fast food was greater than those they got at school.

Samantha Heller, a dietitian, nutritionist, exercise physiologist and clinical nutrition coordinator at the Center for Cancer Care at Griffin Hospital in Derby, Conn., said that "in our fast-paced, time-challenged world, parents are convinced that it is easier and less expensive to eat take-out, fast food and in restaurants."

Unfortunately, these foods are usually high in sodium, fat, sugar and calories, and low in healthy nutrients, she said. "We cannot control where these eateries are located or how they prepare their foods, but we can decide to cook more at home, which will ultimately save money and help keep our families healthy," Heller said.

Although it appears a take-out meal for $4.99 is a great deal, one would actually save money by going to the store buying chicken breasts, vegetables, whole grain pasta, bread and sauce. "You would have a healthy dinner and leftovers for tomorrow's lunch and probably enough left to reinvent dinner by using the remaining ingredients in a salad, frittata or burrito," she added.

"For less than $30, you can buy enough food for several meals including chicken breast, mushrooms, broccoli, pasta, lettuce, bread, eggs, tomato sauce and salad dressing," Heller said.

"A family of four can spend that much easily for just one meal each for take-out and fast food. Planning the week's meals ahead will make home cooking easier, faster, and cost-efficient. More importantly, research suggests that family meals enhance the health and well-being of children on many levels," she said.

"This study is a bit of a wake-up call as to where excess calories are sneaking into children's diets," said Lona Sandon, a spokeswoman with the American Dietetic Association. "More reliance on foods prepared outside the home has led to higher calorie intakes. Eating foods prepared outside of the home has become the norm, not the exception. This makes it more critical to make healthy choices when choosing foods made away from home."

"Also, this study shows that we cannot continue to blame the problem on foods served in the school. Schools have worked hard to change the food environment and offer more healthful choices," Sandon added. "Paying attention to where and what children are eating outside of the school environment is just as important."

More information

For more on healthy eating for children, visit the Nemours Foundation.