Restrictions on fast-food chain restaurants unlikely to reduce obesity: Study

Oct 6 2009

Restrictions on fast-food chain restaurants in South Los Angeles are not addressing the main differences between neighborhood food environments and are unlikely to improve the diet of residents or reduce obesity, according to a new RAND Corporation study.

Researchers from RAND Health found that the South Los Angeles region has no more fast-food chain establishments on a per capita basis than other parts of the city, but rather many more small food stores and other food outlets.

Those outlets are more likely to be the source of high-calorie snacks and soda consumed substantially more often by residents of South Los Angeles as compared to other parts of the city, according to the study published online by the journal Health Affairs.

"The Los Angeles ordinance may have been an important first by being concerned with health outcomes, but it is not the most promising approach to lowering the high rate of obesity in South Los Angeles," said Roland Sturm, the study's lead author and a senior economist at RAND, a nonprofit research organization. "It does not address the main differences we see in the food environment between Los Angeles neighborhoods nor in the diet of residents."

The Los Angeles City Council in August 2008 approved a ban on opening or expanding fast-food restaurants in an area of the city known as South Los Angeles. The ordinance focused on fast food restaurants characterized by "excessive signage, little or no landscaping, large expanses of surface parking, drive-through windows, multiple driveways, parking lots fronting the street" and argued that the low-income region had a higher concentration of fast-food establishments than more-affluent sections of the city.

But an analysis by Sturm and study co-author Dr. Deborah Cohen found that South Los Angeles actually has a lower concentration of fast-food chain restaurants than other parts of the city.

Researchers found there were about 19 fast-food chain restaurants per 100,000 residents in South Los Angeles, while there were 29 per 100,000 people in affluent West Los Angeles and 30 per 100,000 residents for all of Los Angeles County. There are significantly fewer restaurants of any type per person in South Los Angeles compared to Los Angeles County overall, according to the study.

In contrast, the density of small food stores was about double that of the county average and more than three times the number in West Los Angeles. This was partially offset by a lower density of large supermarkets in South Los Angeles.

Researchers also analyzed information from a survey of 1,480 adults from across Los Angeles County that asked residents about their food purchases and habits of eating out. The results showed that adults in South Los Angeles consumed significantly more "discretionary" calories from sugary or salty snacks and soft drinks compared with residents of wealthier neighborhoods.

Residents of South Los Angeles and residents of more-affluent areas reported eating similar amounts of fruits and vegetables each day and had fairly similar levels of physical activity, although residents of South Los Angeles did report watching more television.

Researchers say their work suggests that focusing on the sources of snack calories would address the differences between South Los Angeles and other parts of Los Angeles better than the current ban on new fast-food establishments.

"The ubiquitous availability of food can be overwhelming and stimulate hunger and cravings for food, regardless of whether an individual has a physiological need for nutrition," Cohen said. "Research has made it clear that frequency and saliency of food cues in the environment, the type of foods available, and the portion sizes served, are key issues that effective policies need to address."

One of the goals of the Los Angeles regulation is the creation of more sit-down restaurants, but in terms of diet, this is not necessarily an improvement, according to researchers.

"There is a misconception that sit-down restaurants provide 'healthier' food and are less likely to lead to obesity," Sturm says. "However, when we looked at some common offerings, an average lunch sandwich in a sit-down restaurant had more than the combined calories of three Big Mac hamburgers; many dinner choices have over 2,000 calories and cover the energy needs for a full day. And that does not even include possible appetizers or desserts."

The study also found that residents of South Los Angeles and those from wealthier areas reported eating out in restaurants at about the same frequency, although South Los Angeles residents are more likely to purchase items from a food cart or mobile vender and less likely to eat in a sit-down restaurant.

While residents of South Los Angeles and those from more-affluent areas seem to shop at similar types of stores, there was one dramatic difference -- many South Los Angeles residents walk or take public transit to the market, something seldom done in higher-income areas.

Source: RAND Corporation