What makes food filling?

Every so often, I realize I’m incredibly ignorant about something incredibly commonplace. Like how to hard boil an egg or play Bid Whist. Now: I don’t know what makes food filling.

I asked this question seven or eight months ago, but to no avail, and it’s kind of been bothering me ever since. Just what is it that makes some foods filling. Fats? Calories? Lack of bean sprouts? I apologize for re-asking, but I figured that the SDMB can’t fail me twice. If so, shame on me.

The Abs Diet endorsed by Men’s Health magazine (by David Zinzcenko and Ted Spiker) regularly cites to studies that say that, given otherwise identical meals (ie, identical in calories, nutritional value, etc.), men who eat protein at a meal say they feel full longer. Seems reasonable that that would be one factor.

The sensation of being full is simple: it’s related to the amount of space food takes up in your guts. The sensation of being satiated appears to be tied to your blood sugar levels.

Ok. And beyond that, are we talking about mass here? Because a dinner of 1,000 bean sprouts will definately fill me up less than a bowl of fettucini alfredo.

Following on ultrafilter’s comment about the space in your stomach: something will be more “filling” the longer it keeps taking up space there.

Something can make you feel full but pass through your system quite quickly (eg things with lots of liquid, or some kinds of Chinese food).

In my experience it’s protein and carbohydrate-based fibre (usually from whole grains). If I don’t have both in a meal, I will remain hungry.

Most people eat more protein than they need, and less whole grain, which is how they manage to feel full.

Whole grains take longer to digest (it seems to me, but I could be wrong) than ones that have been stripped (like white rice or white flour).