Health

I'm sure there are many factors, having to do with both non-cultural factors (availability of healthy foods, etc.) and cultural norms. The cultural factors are fascinating. This is just my impression, and I don't have scientific studies to back it up, but "eating like a lib" is definitely frowned upon and there's downright hostility to veganism and vegetarianism in many places. Conversely, meat eating is considered manly and American. "I'm not eating that arugula and rabbit food!" "Michelle Obama isn't going to tell me what to eat!" "I'm a red-blooded American and I'm going to eat as many hamburgers and big chunks of red meat as I can shovel into my mouth!" It can also be an unspoken sentiment. Consuming portions of fried foods and such is just the way people have eaten for decades in certain areas, and being overweight to morbidly obese has been normalized. Kids grow up around obesity and learn not to give these types eating habits a second thought.