Thank you Inger, very good question!
The instincto theory provides two answers, one theoretical and the other empirical.
Theoretical answer (thus doubtful): it is unknown if mankind, nutritionally speaking; originates in Africa. If such were the case, one could quite simply admit for example that the diet of Bushmen must be the most closely corresponding to our genes. They eat indeed meat, but also a big part of plants.
We know now that in these prehistoric times, there was a handful of migrations not expressly known by paleontologists. We are in any case the inheritors of genetic data much older than the pithecanthropus, which himself came from primates. The genome very slowly changes with time, and the epigenetic mechanisms of adaptation remain limited. It is thus necessary to go and see on the primates (or their own ancestors) side to know the starting point of our genes.
But we can’t go back in time. Establish the food range from the archaeological or paleontological data is always questionable, considering the different preservation time of various food. There remains a way then: go and see what the descendants of these primates eat today in nature. There are, at the very least, infinitely more chances that they maintained their old behaviors while living in nature than did men under the effect of culinary and agricultural artifices, or simply by its greater capacity to modify the environment. It is clear that plants are a major part of all the primates diet. The genetically closest to us like chimps and bonobos include in particular a large part of fruits in their diet.
Of course, it cannot be immediately concluded from this that man still has the same digestive and metabolic characteristics. It is necessary for this purpose to compare the digestive tracts and in particular the structures of the digestive enzymes. According to the publications I could access to, there is a great similarity between the characteristics of chimpanzees and humans. It is thus rather probable that we adapted right from the start for a similar food range.
However, the empirical answer is obviously the surest: how does our body function in the long-term with such or such food range? I can testify today, and I am absolutely sure of the following results: in consuming approximately 2/3 of fruits, 1/4 of vegetables and 1/12 of proteins, the long term instinctos are very well. I have personally soon half a century of practice, and I am in a far better shape than the average population of my age. I look 10 or 20 years younger than my real age, as is the case for most long-term instinctos. The
mean BMI (Body Mass Index) calculated out of 43 long terme instinctos is perfectly in the standards, and shows a much narrower dispersion between the various individuals (three times less than in the average population).
But the most important criterion is the growth of children: a body growing from 3 kg to 60 kg is made up for the most part from the nutrients it has received during its growth. If he or she is able to be constituted without deficiency, without accumulations of foreign substances, with normal or even better than average height to weight ratio and performances,it's that he/she found in the diet all the necessary substances, without exception and in proper amount, which means that the alimentary instinct has assumed a right food balance corresponding to the needs. There are a quite a few children fully grown up who were born from instincto mothers and who practiced strictly throughout their life: they are in perfect health and present the desired criteria of normality, without any deprivation symptoms, nor over /underweight. They didn’t have the usual kids illnesses neither.
The fact that all these criteria are satisfied with instinctive nutrition is a proof of good performance, in particular of the alimentary instinct: all these persons practice the choice of foodstuffs by their flavors and they ingest the amount indicated by alliesthesic variations of taste and stomachic signals. But be ware with the reasoning: it doesn’t inevitably imply that a different diet cannot have such favorable effects (there isn’t inevitably exclusion of a diet by another).
The only thing I can say, it is that the “zero carb diet” doesn’t match what can be expected from the evolutionary laws, since nothing implies that our ancestors having had a more carnivorous diet than apes could adapt to it in order to have a equaly good health (it seems Neandertal men, for example, had significant health issues concerning in particular the children, but it’s true that they most probably cooked their meat and perhaps other food). The fact of having survived a period of intensive carnivorism does not mean that health was at its best, but only that reproduction was possible. To be able to deduce that the adaptation to the diet guaranteed an optimal health, it would be necessary to count over much longer periods.
Personally, I stick to the facts: the instinctive nutrition such as I defined it, by taking account of the indications of all the sensory perceptions, allows to obtain an optimal nutritional balance. It is recognizable by the fact that the inflammatory tendency is reduced to a minimum: no infections and no red edging around small wounds, no lasting pain in the event of wound, fracture, etc (the pain of the impact lasts only approximately three minutes), whereas an excessive consumption by forcing the instinct or by eating domesticated animals meat whose savor is softer than wild game meat brings a return of the inflammatory tendency, hyperkeratinisations, neoplasms, etc .
This said and to answer some unsupported affirmations,
nothing allows to demonstrate, either theoretically nor empirically, that humans would not be adapted to the consumption of fruits. Nor that the absence of fruits, if only through the protein over-consumption it generates to compensate for a lack of calories from carbohydrates, would be without long-term effect on health. You undoubtedly heard of the kidney stones of Lex Rooker: it’s almost certainly directly linked with an excess of proteins and uric acid.
But finally, everyone has to do his/her own experiments. I also paid with my health for all those I’ve done in the aim of developing instinctive nutrition.
