All the aforementioned countries' lifestyles differ vastly from ours. I believe that Americans' health disparities are based upon our commericalized, processed, sedentary lifestyles.
-For one, the majority of Asians and Europeans walk or bike everywhere; Americans will drive our BMW's one block to the grocery store to pick up a gallon of milk. The cumulative effects of the exercise or lack of exercise, I believe, has a big effect on our health statuses.
-Portion sizes are much different. Americans tend to supersize and have portion distortion.
-The American diet consists of much more processed foods, processed white flour/white carb products, processed sugar products, than that of europeans and asians. Many Americans practically live on commercialized food products-- hot pockets, tubecake, McDonald's, donuts, etc. Yuck.
-P.S. I HAVE TO say this. I HATE donuts. I think they are the foulest (truly non-)food on the face of this earth. The mere site of them makes me hurl. I've even seen someone eating donuts and bacon, BARF! And I'm an ER Nurse, so donuts are ALWAYS in our break room. When I come onto shift and find a partially finished mega box of the "donut variety pack", I throw it into the trash. I have gotten asked not to do this, but I have a donut vendetta. DONUTS ARE DISGUSTING. WALK PASTA DONUTS!!!!!