Personal experiences will vary...
That being said, I have found for me, smaller portions have become the norm. At first, it was irritating to weigh things out and to find that it was sometimes less than half what I used to eat. But I think my stomach has personally gotten use to smaller meals and appreciates when it doesn't have to stretch as far to accomodate what I used to eat. There is a place my wife and I eat in Philly (so does the rest of Philly, it's just awesome

) called Chickie and Pete's. Let me tell you what I used to eat there.
--About six-seven slices of pizza (mind you, it's thin crust, like VERY thin, and barely any cheese on it, more like a tomato pie, I'd say each slice is about 200 calories in all).
--Magooby Sandwich - shrimp, cheese, onions, pickles and fries on a six inch or so italian roll.
--My own basket of fries with cheese (these are crab fries, and I'd say a basket is probably the size of a SUPER SIZE at McDonalds, maybe 1.2 times bigger?)
Now, if I tried to do that... forget it, I'd be throwing up. I can't hack it anymore.
Now, when I go with my wife, I eat four slices of pizza, half a roast beef and cheese sandwich (same size as the magooby) and split a basket of fries with my wife. Almost half of what I used to eat, granted, it's still around 1500 calories, but its a great cheat meal.
I'd hate to tell you what I used to eat at WaWa for lunch on a daily basis. Now, it's probably 30% of what I used to eat, at least calorically it is about 25% of the original.