Like, when I was a kid, a "serving" of cheerios (the cereal) was something like 1/4 cup. Which was like, 9 "o's." lol. On average, I would eat at least 4 servings in a sitting, and possibly double that besides.
My ILs measure their cereal out by the serving, and eat the smallest amounts of food. They ahve all kinds of health problems, too -- they eat low fat, CW, and about 1800 calories per day (or less). It's sad really.
So, when being grainy (rather than meaty), i needed to eat more volume -- and it wasn't painful for me to eat that if I wanted.
But again, my preference was for fruit/veggies. I much prefer them. Feel lighter.