THURSDAY, June 16 (HealthDay News) -- If a new survey of high school teens in Maine is any indication, locating fast-food outlets near schools may not actually affect students' chances of being overweight.
The survey polled more than 550 students in grades 9 through 12 at 11 schools throughout the state.
On the one hand, it revealed that most teens in the state are indeed consumers of fast-food staples such as burgers, fries, pizza and soft drinks. But it also indicated that the pull toward unhealthful food among these teens appears to be a function of generally bad dietary habits and poor nutritional knowledge, rather than the location of fast-food outlets.
"Our hypothesis was that the so-called 'built environment' -- what a person's environment around them might be -- would have an influence on the [teens'] diet and obesity rate," explained study co-author Janet Whatley Blum, an associate professor in the department of exercise, health and sports science at the University of Southern Maine. "But in terms of their school environment, we did not find that," she said.
"We think the reason for that is that the availability of unhealthy foods is basically ubiquitous," Blum noted. "So while the students said they do go and buy it around their schools, they also said that they also get that same food from home and from local stores near their home. So whether or not fast-food places are near to their schools really doesn't change the overall situation."
Blum and her colleagues report their findings in the July/August issue of the Journal of Nutrition Education and Behavior.
The investigators found that about 25 percent of the students were either overweight or obese, and slightly less than 2 percent were underweight. Half of the students said they drank soda at least once a week, and one in 10 said they drank it every day. About two-thirds said they'd been to an outlet that served burgers and fries in the past month, and half had been to a pizza restaurant.
Fast-food outlets were located within about a half-mile of eight of the 11 schools, according to the survey, and 10 schools had stores nearby that sold soft drinks.
However, the researchers' statistical analysis found no correlation between a risk for being overweight and the proximity of fast-food restaurants to the teens' respective schools.
"This finding suggests that maybe we should be doing more to educate kids as to the impact of unhealthful food," Blum said.
Lona Sandon, a registered dietitian and assistant professor of clinical nutrition at the University of Texas Southwestern Medical Center at Dallas, said that the findings were "surprising, yet not surprising."
"Knowledge is power," Sandon said. "Offering the knowledge of what foods are health-promoting and beneficial is certainly the first place to start. But behavior based on knowledge and the built environment both impact food choices. The question is, what has the biggest impact?
"In this case, they're saying the built environment around these teens is less impactful than what the children know about nutrition, and also less impactful perhaps than what's going on in the home," she said.
The home environment, Sandon stressed, plays a critical role.
"Past research has looked at what students bring to school when they bring their own lunch, and it's actually often less nutritious than if they ate a school lunch, which means that what's going on in the home is often worse in terms of giving kids a sense of what to do in terms of making healthy food decisions," she said. "And that might explain these findings."
Sandon suggested that "if we focus on informing kids as to how best to think about what they're eating, that may be a more impactful way to affect their decisions than trying to change the built environment around them."
The Nemours Foundation offers more on teens and nutrition.
SOURCES: Janet Whatley Blum, Sc.D., associate professor, department of exercise, health and sports science, University of Southern Maine, Gorham, Maine; Lona Sandon, R.D., assistant professor, clinical nutrition, University of Texas Southwestern Medical Center at Dallas; July/August 2011, Journal of Nutrition Education and Behavior
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