Exactly. Our bodies are set to defend against energy LOSS. All of our enzymes, hormones, etc. are tuned for "feast or famine" rather than the constant abundance that agriculture has brought.
True, but you might mean to say, "modern agriculture". That's a product of the Industrial Revolution, artificial fertilizers, and pesticides/herbicides.
And don't forget hybrid crops and crop rotation techniques.
If I could kick my sugar habit, I would lose 25 lbs in no time, as I work hard.