" Has anybody thought of reducing the portion sizes?"

sure they have! Then their competitors advertise with pictures of larger ones. The limit seems to be only what will cause lost profit. We have the concept of "supersize" used as a verb...and you can almost not find ANY product sold in size 'small'. A 'medium' drink is the smallest, and it is often more than I want.

We seem to be the epicenter of eating contests, too! Setting records over how much too much can be stuffed into a body without dying in the process! (But a couple of Japanese kids have been winning)

The USA has had one of the best locations in the world for being able to produce food, and it was easy to assume that 'more' = 'better'.

We are beginning to learn otherwise, but the idea is still ingrained in both the culture and the language.