Funny enough you can order half-portions at many restaurants. That will bring the portions closer to a normal size.
It would be so much easier if it was just what I'm used to here: if you just order food, you'll get enough for a 'normal' eater. You can always go bigger or smaller, depending on if you are a 'big eater' or not. The default in the US seems to be that the size of the standard order needs to satisfy a giant construction worker who hasn't eaten for two days.
I remember ordering blueberry pancakes for breakfast once, and got a pile a that was almost a foot high. Even though the pancakes were actually pretty good, I think I finished less then 1/4th of them. That just makes no sense.