I'm not that much of a meat eater myself, but wouldn't want to live completely without it (especially in BBQ season
). My girlfriend also eats very little meat, but gets this craving every few weeks, where I usually end up having to cook her something with meat. I guess its like Squeak said, we feel a natural compulsion to eat what we need. I know several people who are quite happy and healthy as vegetarians, although one only recently started eating meat again...
Anyway, as much as I enjoy the vegetarian discussion, I wanted to get back on the original topic. Personally, my impression from my last trip to the US (4 weeks last september) is, that its definitely a bit "harder" to live healthy in the US, than for example here in Germany. Portion size might play a role, but IMO that's not the main point.
One of the things I noticed is the whole restaurant culture (or lack thereof) outside major cities. Fast food (I guess its universally agreed upon that burgers and fries are not healthy if eaten regularly) is by far the most widely available and affordable food. You can feed an entire family for the same money you'd pay in a restaurant for one person and you can get it anywhere, anytime.
In most small towns we've pased through, we'd usually find about 2-3 times as many fast food places as other restaurants. To add insult to injury, those other restaurants often close early and their menu is usually not much different from a fast food place either. The only regularly encountered alternative was the pizza places, yet pizza is hardly much better than burgers, especially considering the average size of an american pizza. The larger towns start having some ethnical restaurants, take-aways and stuff, but compared to Wendy's, McD, BK and Taco Bell they are truly rare from my experience. If you want to eat somewhat healthy, you have to rely on home cooking, which pretty much sucks for tourists.
The major cities paint a different picture though. While fast food is still dominant, there are many great restaurants and cafés. Prices tend to make this more of a upper-class thing, but its high quality stuff!
In contrast "normal" restaurants, including foreign cuisine, are far more widely spread and affordable in Germany than in the US, even in remote areas (although remote in Germany is something quite different, meaning more like 25km to the next bigger town instead of 200km as in the US). Fast food is increasingly popular, but still restricted to cities and high traffic/tourist regions. It's also cheaper than eating in a restaurant here, but not as much as in the US.
You could also look at the supermarkets. I love browsing through supermarkets in foreign countries. IMO it gives you a good feel for what the people consume in their private lives, its more authentic than just going by what you see on the streets and read in a guide. American supermarkets are cool! I really like them. But I was surprised that groceries, vegetables and fruit in particular but also stuff like cheese and other milk products, are usually quite expensive. I didn't pay attention to meat prices but in general it seems like, again, fast food is a hell of a lot cheaper for people (than cooking their own meals). Clothing and electronic goods are cheaper though, which is kinda cool. 8)
Another thing, which isn't limited to the US, is this frickin' white bread. What's up with that? While its possible to get some decent bread in bakeries and good supermarkets, its nowhere near the same level of variety as here in Germany. To be honest, that can be said about most countries, even France and Italy, which both have great breads but don't come close to the variety offered here. Bread can be something so great, its sad that 98% of the US populace is missing out on how great one of the most basic and important provisions can be.
And what's the deal with sodas? This hyper-sweet stuff is neither healthy, nor does it taste good ... why is it the only thing you can get to drink everywhere (besides water, which sometimes unfortunatelly tastes like weaponized chloride)?
Its really the same as with the vegetarian discussion I guess. It takes a more conscious effort to live and eat healthy in the US, than it would in other countries. Its certainly possible and if you know what you do, you can probably eat just as, if not more healthy than elsewhere. Mainstream food culture tends to put "fast and cheap" before "tasty and good" though.
All highly subjective of course...