This is where the book, Death by Food Pyramid, is still the only work I am aware of which explores this angle.

We are all a collection of what our ancestors ate. They gave us different enzyme patterns. Without the right enzymes to break down food into useful nutritional components, food becomes far less nourishing, or even actually harmful.

My symptoms of gluten sensitivity were not those of celiac; and I don't have celiac, I'm sure. What I got was a painless swelling of my intestines. When I realized, I stopped eating gluten. Now, years later, I can't take one bite of gluten without feeling nauseated, and eating more produces a "stomach on fire" reaction that I'll never risk voluntarily.

My reaction to lectins (legumes, brown rice, soy) is even more dramatic. I don't get any warning that there's lectins in what I'm eating, until hours later, when my body acts like I've been poisoned like something out of Game of Thrones.

I had no idea my body was reacting to such common staples of food. I had to not eat them for weeks... and now I can't eat them at all.

But all along I was eating them, and they were making me fat and sick? Now, I think so.