Something like Quaker Puffed Rice is not really sugary. The idea is that the air fills you up--it stretches your stomach without adding more calories. Same is true of a big salad--things like that.
This is pretty clear with something like popcorn--if I eat a big bowl (1 serving) of popcorn (Orville R's Light Natural), it's a 110 calorie snack but I'm full after I'm done with it. I'm not inclined to keep on snacking after that.
So I think there's a distinction we're losing here between feeling full and feeling satisfied. Better food tends to leave one feeling more satisfied, though not necessarily full. Or have I wigged out here...
Jay