The obesity epidemic has much less to do with cars and much more to do with cheapness of food and volume consumed.

A typical deli sandwich in the US should be enough to last any normal person three days. Same goes for e.g. ice cream from Shake Shack (random example I know, but one I came across recently). If you buy one of these and eat them in one sitting, the answer to "why am I obese" is simply "you eat way too much."

Sorry, don't exaggerate please.

A Subway sandwhich is about 600 calories. That's about 1/3 of the daily 2000 calories standard. A Shake Shack shake tops out at 1010 calories, a half of the daily norm.