The food environment and obesity link

September 25, 2009

A study published earlier this month in the Journal of Urban Health examined the link between restaurant density, including fast food, Body Mass Index (BMI) and how the two are possibly affected or moderated by owning a car.

A study published earlier this month in the Journal of Urban Health examined the link between restaurant density, including fast food, Body Mass Index (BMI) and how the two are possibly affected or moderated by owning a car. Data from the Los Angeles Family and Neighborhood Survey (L.A.FANS) and the 2000 U.S. Census on fast food was reviewed; individual-level factors and residential socioeconomic status (SES) were taken into account and adjusted for.
Food environments are a hot topic in understanding obesity risks; fast food restaurants have be under the firing squad recently as nutrition information has been made widely available, posted both in stores and on the web, revealing more than most of us want to know about our cheap belly filling fixes. The Chain Restaurant Industry Review reported that fast food sales have increased well over $100 billion in the past 30 years; while a parallel increase in our waistlines has also occurred. Americans weigh an average of 25 pounds more today than 30 years ago, according to the Centers for Disease Control and Prevention (CDC).
Among its main conclusions, the study found that a high concentration of local and fast food restaurants is positively associated with BMI. Those who own cars have higher BMIs than non-car owners for probably the obvious reason that non-car owners have to walk more often to reach their destinations thus exerting more energy. Generally, car owners weigh 8.5 pounds more than non-car owners. People living in areas without fast food options weighed the least overall regardless of car ownership.
However, one of the most important findings is that when non-car owners living in fast food dense and ‘sparse’ areas are compared, those living in fast food dense areas tend to have higher BMIs and weigh on average 12 pounds more (based on height of 5’5”). And to compare those living in the same fast food dense neighborhoods, non-car owners weigh 2.7 pounds on average more than car owners. Thirty-eight percent of the sampled population lived in the lowest SES neighborhood quartile, and nearly 70% of the total sample lived in the two lowest SES neighborhood quartiles.
The results of this study support the idea that food environments significantly influence obesity risk; and car-less adults living in close proximity to a large number of fast food outlets are at especially high risk. The study suggests that those able to travel farther i.e. have cars, have access to a variety of healthier food options as opposed to those limited to their neighborhoods. Low-income neighborhoods are also known to be ‘food deserts,’ which are home to a variety of fast food restaurants and have little availability to healthier food offerings.

Click here to access the full study.