THURSDAY, Jan. 21, 2016 (HealthDay News) -- Maybe living close to a large supermarket can help obese children slim down, new research suggests.
"Children enrolled in an obesity intervention program who lived closer to a supermarket decreased their body mass index (BMI) and increased their fruit and vegetable intake," said Dr. Lauren Fiechtner, study lead author and director of nutrition at MassGeneral Hospital for Children in Boston.
But supermarket proximity alone might not have tipped the scales. The kids whose habits changed the most were also enrolled in a weight-loss program and given advice on how to make better food choices, Fiechtner said.
Obesity is a major public health issue in the United States. The percentage of obese children aged 6 to 11 more than doubled to nearly 18 percent between 1980 and 2012, according to the U.S. Centers for Disease Control and Prevention. Previous evidence suggests that access to retailers selling healthful foods might help improve weight.
For the study, published online Jan. 21 in the American Journal of Public Health, researchers followed nearly 500 children, ages 6 to 12, who were participating in an obesity trial in Massachusetts between 2011 and 2013. All had a body mass index (BMI) at or above the 95th percentile. BMI is a measure of body fat based on height and weight.
Some kids received usual care, while others got targeted weight loss interventions, with components such as health coaches, newsletters telling parents how to encourage fruit and vegetable intake, and kid-friendly recipes.
Closeness to a supermarket appeared linked to greater fruit and vegetable intake and weight loss, but had no effect on sugary beverage intake, the study found. Sugary beverages have been linked with weight gain.
With each 1-mile decrease in distance to a supermarket, those in the weight loss group increased their fruit and vegetable intake by .29 servings every day and decreased their BMI a small amount -- an average of 0.04 units -- compared to the usual-care group. For reference, a BMI change of 0.05 units for a 9-year-old girl in the 95th percentile for BMI is 1.1 pounds, according to the study.
When the researchers plugged in factors such as household income and level of education, the positive effect of a nearby supermarket weakened, however.
Previous research on access to food stores has produced conflicting findings. In one study, Brian Elbel of New York University found children's diets didn't change much after a full-service supermarket opened in their low-income neighborhood.
"We looked at the influence of supermarkets overall," said Elbel, an associate professor of population health and health policy. "These authors looked at the influence specifically for those enrolled in an obesity program. I think this paper shows us that in certain circumstances, including for those who are motivated to lose weight, supermarket access could be an important contributor."
The findings should be interpreted cautiously, said Jennifer Temple, an associate professor in the department of community health and health behavior at the State University of New York at Buffalo, who was not involved in the new study.
The researchers found a link, she said, but "it is impossible to determine whether grocery store proximity caused the difference in BMI change or in fruit and vegetable intake."
Improvements in fruit and vegetable consumption and BMI may be due to other factors, such as household income, she said.
Future research "should focus on weight-loss interventions that are tailored to families that have limited access to grocery stores in order to help them make healthier food choices in the stores and restaurants that are easily available to them," Temple said.
These healthier choices might include purchasing canned and frozen vegetables and/or using local farmers' markets when available, she added.
Fiechtner suggested buying longer-lasting produce. "Apples last one or two weeks sometimes," she pointed out. Oranges tend to outlast grapes and bananas, she noted. Frozen fruit with no sugar added is another option, she said.
For help increasing fruit and vegetable consumption, see Alliance for a Healthier Generation.