I suppose I'm more "ecto" than anything.
I think of this > I know someone who has built a lot of muscle, and during one hot evening he really felt the heat. Now I can see maybe why > all that muscle was burning energy to make him feel the heat . . . possibly. Meanwhile, excess fat layering can hold heat in. Maybe he has both . . . a lot of deeper muscle, and some lazy fat holding the heat in, now that he's more busy with ministry and not working out so much . . . maybe.
Another item I might have discovered > I eat in the morning and then I can forget that food exists until I'm back at the end of the day. I can do a lot or a little, but not get hungry . . . all day.
Well > in the morning I start with trail mix, yogurt, meat, boiled vegetables, spinach salad . . . things which make the body work to get the energy of these foods. And so it takes all day long to get the energy out of my breakfast - - because I eat what I call "slow-release" foods.
But because it is slow-releasing, I have only so much energy at any point in a day. I can do only so much before I hit sort of a ceiling and can't go up any more.