"Be aware that a portion size isn't designed to make you 'full up' - it's designed to satisfy and nourish you. There's a big difference between being satisfied, i.e. eating enough, and being full up. When you are full up, the uncomfortable sensation you get is your stomach telling you it is over-distended (stretched). Unfortunately, people get used to this sensation and program themselves, or anchor it, to be the feeling they think they should get after every meal, and they don't stop eating until they get it."