> French people couldn't be wrong: they consume plenty of rich food and they don't have American health problems.

And you know why your average American turns into an unhealthy tub of lard ?

Simple really:

     1) Americans have a penchant for over-processed foods which in turn contain high-levels of "the wrong" fats and, of course, sugar (which in America is generally the horrible processed type, e.g. corn syrup) .
     2) American portion sizes for one meal could feed an entire African family for a week, American portions are obscene
     3) Americans are largely sedentary, and have a penchant for driving instead of walking
     4) Americans have a penchant for intensive industrial farming which reduces the quality of the raw ingredient
     

Now, you may choose to try to argue over point (4) if you feel you must be patriotic and defend US agriculture. But points (1)–(3) are, regrettably hard truths.

It's not rocket science.

Eat Less. Eat Better. Do Some Exercise. Your body will thank you.