[coryfklein]

No, but on a higher meta-level it is contagious. Obesity is more prevalent in societies where high-caloric foods are more readily available. Now I'm more libertarian leaning myself so I wouldn't actually advocate for this, but if we mandated a cap on calorie-per-serving for "foods", you'd see a drastic drop in the availability of high carbohydrate foods (particularly sugar) which would essentially cause forced sugar-withdrawal in most of the population.

A couple months later? Everyone's sugar-thermostats are reset, the lower-calorie food tastes nearly as good – if not better – and obesity rates would plummet.

However, since we don't/can't coordinate such a thing on a national level, everyone gets exposed to constantly increasing carb content in their food, and maintaining a lower calorie diet requires significantly more effort. I can speak from personal experience, I simulated this on a personal level when I moved to South Korea for 2 years where sugar is nearly non-existent. As a modestly thin person I lost an additional 15-20 pounds while I was there without having to work hard or suffer with worse-tasting food (well, I did experience sugar withdrawal for the first couple months).