Eating out can have both positive and negative impact on obesity

Eating out instead of cooking at home continues to increase as a factor impacting the American diet. Americans face a large variety of food options and food establishments when choosing to eat out.

Do the choices of available restaurants matter to America's rising obesity? In a study published in the February 2008 issue of the American Journal of Preventive Medicine, researchers found that the availability of more "fast food" restaurants compared to "full service" restaurants can contribute to higher levels of obesity.

Drawing on data from 5 years of the Behavioral Risk Factor Surveillance System (BRFSS), an annual telephone health survey of the adult population of the US and the 2002 U.S. Economic Census, the researchers examined the relationship between restaurant availability and weight status in 544 US counties. This resulted in over 700,000 BRFSS respondents, representative of approximately 75% of the 2002 US population.

The researchers found that a higher total restaurant density is significantly associated with lower weight status. However, once the restaurants are split into components: fast food and full service, a higher full-service restaurant density is significantly associated with lower weight status while, in contrast, a higher fast-food density is associated with higher weight status.

Writing in the article, Neil Mehta, MSc, Population Studies Center, University of Pennsylvania and Virginia W. Chang, MD, PhD, University of Pennsylvania School of Medicine, state that, “The results reported here demonstrate that the restaurant environment is associated with weight status net of individual- and county-level factors. The relationship is complex, suggesting that the restaurant environment's influence goes well beyond a simple positive association between restaurant density and weight status. Rather, different components of the restaurant environment exhibit differential associations with weight status. Individuals residing in areas with a high density of total and full-service restaurants exhibit lower weight status, possibly indicating that these areas possess a more advantageous eating environment...Those who reside in areas possessing a higher relative number of fast-food to full-service restaurants have a higher weight status. Hence, the relative availability of alternative types of away-from-home eating establishments may most accurately capture the set of food choices available to individuals and may be salient in determining eating behaviors and ultimately weight status. Results from this study support the notion that fast-food restaurants are a contributor to obesogenic environments.