I believe that there is No Single Ideal Human Diet. The human digestive tract mimics that of a Omnivorous organism (not strictly vegetarian, or strictly carnivorous). Groups of modern humans (about 100,000 years ago) have adapted over the millennia to regional areas based on climate, elevation and terrain. Within those regions, the local human’s digestive biomes became adapted to the energy/caloric capacities that were available based on the seasonally changing carrying capacities of those lands within those micro-ecosystems of flora and fauna. More extreme temperate climates (and their resulting limited availability of food resources) caused humans to adapt food/nutrient procurement strategies and food production techniques accordingly.
All of that technical terminology is simply to say that originally human hunter gatherer groups subsisted on an omnivorous diet based on where they lived and moved. The plants and animals that were available in those areas were different, and changed at different times of the year. This meant that some human groups ate a higher percentage of animal based foods, some ate a higher percentage of plant based foods.
Whether they are mainly plant based or animal based is not the issue here, but in the fact that all foods consumed for most of our human history were minimally adulterated (with typically only 2 levels of adulteration: hand harvesting and cooking). What constitutes an Adulteration? Adulteration = ANY commercial manipulation done to the natural food. This includes the use of genetically modified or hybridized seeds, every addition of chemical fertilizers, every addition of herbicides or pesticides, the addition of chemicals for curing/ripening/drying the food, the mechanical harvesting and sorting of the food, ethylene gassing to artificially ripen fruits, every use of refrigeration/freezing for transport/storage, every chemical washing, every physical manipulation in the commercial kitchen (cutting, peeling, chopping, juicing, pressing), all the cooking/pasteurizing/sanitizing of food, all the microwaving/reheating of food right before consumption, macerating & digestion.
About 10,000 years ago, this all changed with the introduction of Agriculture, at great cost to our physiology and social dynamics (but more on that in a different article). Still, with the advent of Agriculture, domesticated plants and animals were only mildly adulterated. Since the technology of complex chemical fertilizers and animal feeds did not yet exist, animals raised for consumption still ate what the majority of their counterparts in the wild ate; and plants grew in soil that still maintained nutritive and bio-active properties (from compost, manure, etc.).
Therefore, more of our human history has been spent with the wild food resources as hunter gatherer groups (approx 90,000 years), than with Agriculture (10,000 years). Unfortunately, within the last 100 years, this has majorly changed. We have severely adulterated the landscape, the flora, the fauna, and the forms by which humans produce, consume and absorb their food energy.
The Small Farm Agriculture Model was generally practiced worldwide and varied in size and production capacity, until technologies were developed in the Industrial Revolution such as crop rotation, mechanization,and selective breeding. These technologies, coupled with the drive to feed the growing human population, lead to the introduction of large monoculture farming about 100-150 years ago.
This major transition to our food production happened within the last 200 years, but it is a small blip on the radar in terms of timeframes for human adaptation. Humans slowly adapted their digestive tracts and internal biomes based on the slow adaptation of wild foods to their domesticated counterparts (adapting over the last 10,000 years). Unfortunately today’s commercially produced foods are changing faster than our ability to adapt to the high chemical additive, high sugar, low nutrient, low fiber content, and low water content foods being produced on a mass scale.
Therefore, today most food that is commercially available is:
1. Not Wild caught or harvested.
2. Has deviated from the original small farm agriculture model.
3. Is produced with the commercial and profit-centered goals of high Shelf Stability, high Storage Capacity and high Portability instead of freshness, high nutrient value, high flavor profile and high variety.