Full On Empty

On Saturday I went to get a massage. (an awesome deal at $30 for an hour-long massage, btw.) During the session I was talking with the massage therapist and as the usual "what do you do" question led to others, she asked me if the Japanese really were healthier than Americans. I answered that they probably are, they certainly eat a lot less than we do. The student-therapist told me she waitressed this summer and noticed that the European customers at the restaurant ate so differently from the locals; they were very picky about what they ate and usually ate only about half of what was served. It all got me to wondering, once again, why we in this country are so obsessed with stuffing ourselves silly. I know there are plenty of researchers who will point to evolutionary reasons, but other countries that also enjoy abundant resources don't pig out American style. Sure the details of what we eat play a part, but I'm thinking strictly of volume. What's the void that developed over the past ten or twenty years that is begging to be filled with ever greater quantities of super-sized food?
When I was a kid, no matter how much I ate I never felt over-full. This appalled and worried my parents, especially my mother. Somehow over time I developed the ability to actually feel full and even uncomfortable as a result of overeating. I don't always pay attention to that, but most of the time I try to pay attention to the hara hachi-bu ("eat until you are 80% full) feeling that's common sense in Japan.