If you follow the health news, you might have heard about the food swamp study published by the Rand Corporation. The study correlates obesity to the density of fast food restaurants, convenience stores and grocery stores in Los Angeles. It's interesting reading, even if you don't live in LA.
The study finds that the amount of fast food restaurants doesn't vary much between the obese and fit neighborhoods. What does vary is the amount of convenience and small grocery stores versus large grocery stores. The smaller stores sell what the study generously calls "high-energy foods". You know this stuff - potato chips, candy bars, hot dogs on those roller grills. These are the calorie bombs. Neighborhoods that have only small and convenience stores are food swamps of high caloric food options and a correspondingly higher rate of obesity. People with access to large groceries have a huge advantage in keeping their weight reasonable. Their stores have those high energy foods, but they also have fresh fruit, veggies, healthy grains. The stuff you need for a balanced diet that doesn't give you a butt that hangs off both sides of the barstool.
Even if you have access to large stores, there are times when you have to dip into the swamp of convenience foods. I've gone into 7-11 and hunted for anything reasonably healthy. (I get the 2 hard boiled eggs and whatever fruit cup they've got.) In fairness, 7-11 isn't the worst. A lot small neighborhood convenience stores make 7-11 look like a farmers market. At best, you might find Light Beer.
After reading the study, I decided to go back to carrying some healthy snacks in my car. Next time I need to storm the aisle of the convenience store, I want to remember that it's a calorie swamp.