I have read both the Ultra Metabolism and Ultra Simple Diet books, and it is my understanding that a protein shake is to be used as a breakfast, snack, or supplement with any meal. You can add berries or any non-citrus fruit and nut butters to enhance the flavor. My favorite shake uses soft tofu and soy milk instead of the powders, but I will sometimes add the rice protein powder to bulk it up. Also the Ultra Simple Diet adds ground flax and flax/borage oil up to twice a day, which really helps keep you satisfied.

I've been on a diet plan that uses shakes with all meals and I found it very boring. I got so sick of the shakes I started skipping them and found myself extremly hungry, because the calories were so limited. Dr Hyman is not limiting the calories as much as eliminating the foods that make our bodies function improperly or cause allergies.

I am not really sure how he feels about protein and it's effects on the metabolism, since he does not specifically address it in either book, but I do think we should train ourselves to eat naturally and create a lifestyle that we will maintain, if that includes protein shakes, great.