WHOLE grains still aren't good for you. It's like the new soft drinks proudly advertising "Now with REAL Cane Sugar!" -- it's still horrible for you.
And i would rather eat a tablespoon of raw cane sugar than a tablespoon of bleached white sugar or laboratory grade high fructose corn syrup anyday. (we replaced white sugar with raw cane sugar in our house in spite of scientifically minded opinions that "it's till sugar")
In my worldview we were not dumped blindly into this world to use our senses and scientific knowledge to discover a better world. There is much traditional knowledge that is not discovered, but rather given to us that i am happy to follow instead of trying to discover the next best thing to hack my body.
I am not trying to be close minded, but I am doubting the efficacy of starting from scratch.
What the studies (should) be trying to do is figure out what our bodies are optimized to eat. Additionally, it would be helpful to know if certain genetics adapted to different environments (foods) or if everyone roughly follows the same "optimization".
Also, how long exactly does it take human digestion to adapt? Are there any studies about that? Bear in mind that not only the human genome is involved, but also bacteria and so on in the gut.
Who knows, perhaps part of the human success story is that they can adapt to lots of different diets quickly (humans living in the weirdest places with constrained food sources).
I've read that for example lactose tolerance (the ability to digest dairy products as an adult) spread relatively quickly through the population (can't find exact quotation right now, unfortunately :-( ).
There are no hunter gatherers because agriculture will guarantee a more prosperous and growing population. There is absolutely no doubt about that.
However, just because hunter-gatherers died off doesn't mean their average health was less than the average health of the agricultural population. In fact, the hunter gatherers that were proficient enough to survive were probably much, much healthier than agriculture population. (This is assuming both populations are getting enough nutrients that malnutrition is not a factor.)
Even though the average health of the agricultural population may have been lower, the methods allowed more in the population to survive. In a food constrained world, this is the optimal solution for health.
We don't have the problems of food constraint (at least in the first world provided you have an income). That is why now we can look back out or diets and selectively pick and choose the most optimal combinations because there is no longer a problem of food scarcity.
edit, yes i realized later also the evolutinites have a common ancestor theory, so I should say:
I don't believe that we evolved from a proto-mythical-man-ape, sorry.
Even if we were "created", I would assume we would be created with some kind of optimization for the environment we were created in.
In Vedic epistemology there are 3 ways to ascertain knowledge, your senses, inductive logic and hearing from an authority. There are detailed descriptions on the theory of food, medicine and the functioning of the body. The reductionist view of counting calories and chemicals in a laboratory will never come up to it's standard because the human body is far more complex.