It drives my friends bonkers. My family are somewhat more understanding of it.
Whenever I'm round at a friend's house or out for a meal, the servings are usually HUGE. Maybe twice or even three times what I'd serve myself. I feel satisfied very quickly and hate eating until I feel 'full' - that just makes me uncomfortable. I've never had an ED by the way and my weight has always been very stable. I just seem to be in the minority among the people I know.
I'm trying to get DH to lose weight and trying to make him understand that he doesn't need to eat past the 'I'm not hungry anymore' stage. He disagrees and says he eats lots because it tastes nice and he hates seeing food go to waste. I just think he doesn't know when to stop 
So AIBU?