In my experience, the BIGGEST difference from Euro (French in my case) food theory from American is that nobody here accepts the idea that food is a scientific tool to engineer your body.

Good food is like good art or good music, it's just good because it's good, and it would be considered uncivilized to speak about it in terms of some engineered material designed to illicit a particular response.

Americans have a tenancy to focus on portion sizes because they are a metric which can be analyzed, but that comes back to the main difference - Americans analyze food, Europeans don't.

There are "fancy" restaurants which serve small portion sizes, but that's an overpriced scam for tourists. Real French food is good and also plenty, and French interpretations of American food are fantastic.