WEDNESDAY, Feb. 13, 2013 (HealthDay News) -- Living in an area with many outdoor fast-food ads may be linked to weight gain, according to a new study.
Researchers from the University of California, Los Angeles, found that people living in areas with the most outdoor food advertising were more likely to be obese than residents of areas without these signs and billboards. Although they didn't say the ads cause weight gain, they did note a "modest but clinically meaningful increased likelihood of obesity."
"Obesity is a significant health problem, so we need to know the factors that contribute to the overeating of processed food," Dr. Lenard Lesser, who conducted the study while he was a Robert Wood Johnson Foundation clinical scholar in the UCLA Department of Family Medicine, said in a university news release. "Previous research has found that fast-food ads are more prevalent in low-income, minority areas, and laboratory studies have shown that marketing gets people to eat more."
For the study, published online Jan. 10 in the journal BMC Public Health, the researchers examined 200 census tracts from two densely populated areas. One area was in Los Angeles, the other was in New Orleans. High- and low-income individuals lived in both places.
Information on all the outdoor food ads in both areas was also analyzed. The researchers compared this information to the health of 2,600 adults living in those areas, which they ascertained through phone surveys. Participants, who ranged in age from 18 to 98 years old, were asked about their weight, body-mass index (a calculation of body fat based on height and weight) and soda consumption.
They detected an increased likelihood of obesity in neighborhoods with the most outdoor fast-food ads. "For instance, in a typical census tract with about 5,000 people, if 30 percent of the outdoor ads were devoted to food, we would expect to find an additional 100 to 150 people who are obese, compared with a census tract without any food ads," explained Lesser.
The researchers said more studies are needed in other locations to investigate the link between outdoor fast-food ads and risk for obesity.
If the additional research confirms the association, "policy approaches may be important to reduce the amount of food advertising in urban areas," the researchers wrote. "Innovative strategies, such as warning labels, counter-advertising or a tax on obesogenic advertising should be tested as possible public-health interventions for reducing the prevalence of obesity."
The U.S. Centers for Disease Control and Prevention provides more information on obesity.