Humans were hunter-gathers for hundreds of thousands of years. We evolved from the other great apes, and our gut is adapted to survive on a diet of meat, fish, nuts and fresh vegetables. There is a lot of evidence that our ancestors got approximately 50% of their nutrition from animal products. Agriculture only dates back to around 25 – 50,000 years, which is a blink of an eye in evolutionary terms. So how can our digestive systems digest grains effectively? Are there any nutritionists out there who can explain this? As a rather scientifically inclined layman I would expect that a "Caveman Diet" should be a lot healthier than one based on whole grains and veggies.