"The paleo diet essentially allows lean meats, fish, veggies, some fruit, tree nuts (not peanuts) and seeds, little starch, and no sugar. This excludes… grains, legumes, white potatoes, dairy, and corn. Think about it this way… the things that are excluded are the food items that people are more often allergic to or just have issues digesting. White potatoes and corn just turn into sugar." Interesting premise, and i certainly can see the benefit of cutting down on the latter group and increasing some or most of the first group, but there are definitely exceptions to the rule regarding ease of digestion in the latter group. For example, brown rice for grains, lentils for legumes, goat and sheep milk for dairy and cultured forms of cow dairy. While quinoa, amaranth, and buckwheat are technically considered seeds, they are good substitutes for/in the grain category. Oats well prepared are pretty good. Cultured goat and sheep milk is very easy to fully digest and fairly nutritious. If a goat or sheep is treated well, is happy, and eats healthy food and drinks clean water, and so is healthy, no one can tell me that straight milk or especially cultured versions of same, is unhealthy in moderation. I have a fair amount of food issues, and have had to cut out a lot of foods i like due to problems with digestion, intolerance reactions, etc, but goat and sheep dairy definitely are not on that list. This is why i don't follow specific diets so much as listen to my own body, experiment, and synthesize various different dietary information to find similarities and common ground. Diets, like a lot of codified belief systems, generally contain some dogma and inaccuracy. Civilization dates for example, every few years or so it seems, is getting pushed back further and further as to ancient history and when relatively advanced and organized ones sprung up (with agriculture often being an important part of the development). If it keeps getting pushed back, this could have ramifications for paleo theories. And nobody knows exactly how long it does or doesn't take for the human body to adapt to a food or general diet. Balance, moderation, variety, and naturalness seem to be more key overall. Also, i wished people used common sense more. While i agree with some vegan principles, try eating a vegan diet up in the Arctic and being healthy or comfortable. You need the high amount of fat and protein up there, and non animal sources of same aren't as nutritious as the traditional diets of those who adapted to those regions (lots of organ meats with necessary high amounts of vitamin A, D, etc). Considering how thermic producing complex and dense sources of protein are and how much water it takes to process, it doesn't make sense to eat a lot of animal protein living near the hot areas of equatorial regions if there is plenty of nutritious, non animal foods to eat. Relativity.