by Lauren Fiechtner, MD
There is evidence that the obesity epidemic has been driven by an increase in the availability of processed, affordable, and highly marketed food, leading to over-consumption. But on the flip side, research on whether access to healthy food establishments promotes healthy eating has shown mixed and contradictory results. A few studies have shown a protective effect of supermarkets, others have found no association, and some have found an adverse effect.
Why the varying results? Doing research on the built environment can be difficult because "not-so-good" food establishments often are located close to "good" food establishments (i.e., a fast-food restaurant within or sharing a parking lot with a supermarket). When these places overlap, it’s really hard to know how they are affecting people who live or work near them. Furthermore, the commercial databases used to identify supermarkets for research aren’t perfect; they have lots of mistakes.
People have complex lives too. Most studies do not ask participants which supermarket they shop at, but simply map the participants to the closest supermarket. We know this is not adequate. Some of us shop far away from our homes (or closer to work) because we like the store, we like the prices, or it’s convenient for other reasons. Another big hurdle is that we can’t really define healthy and unhealthy food establishments. Supermarkets sell lots of junk food, and you can eat healthfully even at fast-food restaurants.
So what is the true relationship between supermarkets and children’s BMI? Stay tuned. We are conducting a study which asks families the top five food establishments they shop at and links them to validated addresses and information on the quality, availability, and price of healthy and unhealthy foods in each of these establishments. We hope with improved methods we may be better able to finally answer this question.