Yes, until 10,000 years ago, the majority of the calories in the diet of humans came from animal products.
The summary of all major studies on this matter concludes that 73% of humans living during that period of time (97.5% of the existence of “modern humans”) obtained the majority of their nutrition from meat & animal products.
This started to change 10,000 years ago as farming was “invented”. Diets started to change with the introduction of grains as well as domesticated animals (e.g. cows, sheep, goat, chicken, etc.).
These arguments form the foundation of the “paleo” diet, and based on which advocates of the “paleo” diet make the claim that our diets should be based primarily on animal products, because that’s how our bodies (including our DNA / genes) evolved.
And there is a lot of truth to that: our genetics adapt very VERY slowly, and when our genes are used to a certain diet for 390,000 years, our bodies will have trouble adapting to a diet that’s only 10,000 years old (less than 2.5% of our existence).
I’m not criticizing the “paleo” diet: in fact, I think it has a lot of good components to it. A lot of the reasoning behind how human diets evolved and how our bodies evolved is based on actual science and it does make sense.
HOWEVER: there is something obvious that the majority of people who promote a “paleo” diet get wrong: nutrient density of animal products.
Let’s start with what the “paleo people” get right:
Majority of ancient humans obtained most of the calories from animal products: that’s actually true based on all the studies about ancient civilizations (at least for 73% of humans pre-10,000 years, more than 95% of human existence)
Meat-based diets are more calorie dense and helped human brains grow: again, true. This is why the human brain was able to grow significantly faster than ape-brain, and why the human brain consumes 20% of our energy daily, while the ape brain consumes only 8%. It’s also why our digestive system has shrunk significantly 400,000 years ago compared to apes, because we don’t have to digest a lot of fibre from eating a large quantity of plants.
So the “paleo” diet does have a lot going for it. Except there are 2 caveats:
Hunters don’t always get their prey. In fact, they seldom do. This means that “ancient humans” ate a LOT of meat for 1 or 2 days, and then went for 2,3,4 days or even weeks without ANY meat or animal products. During those times, they supplemented their diet with honey (occasionally) and some plants (when they could find them), and LOTS of FASTING.
Ancient people ate “nose to tail”: they knew that the MAJORITY of the nutrition (especially vitamins, minerals, fatty acids) are NOT in the “muscle meat”, but in the organ meats: heart, liver, kidneys, brain. In fact, there is plenty of evidence that ancient humans ONLY ate organ meats, and then gave muscle meat to dogs or used them to attract other animals to hunt.
So my recommendation is to use an adaptation to the popularized “paleo” diet:
Focus on nutrient density, quality, and variety.
Go for periods of time with 0 animal products.
Eat organ meats.
Get your veggies in (for key micronutrients).
Get quality animal products: organic, free range , grass fed & finished.
Fast for periods of time.
Animal products do have a place in your diet and are important for your health, but so are days when you don’t consume ANY animal products, because, at the end of the day, THAT’s how our bodies and DNA evolved for the majority of our existence on this planet.