Let's open a biology textbook.
We are primates
The human being is an oversized primate. A big ape. This isn't an opinion: we share 99% of our DNA with chimpanzees and slightly less with gorillas and bonobos.
Primates range from vegetarian to "almost-vegetarian omnivores": they eat plants but occasionally enjoy small birds, insects, and sometimes even attack other monkeys. Fair enough.
Every recent meta-study confirms that the healthiest humans tend to eat vegetarian or near-vegetarian diets. Predictably, when you get cancer, doctors convert you to a vegetarian diet. When you're heading for a heart attack, any sensible doctor steers you toward plant-based eating.
How funny that a species of primates — naturally inclined toward plants — does better eating less meat. What an unexpected surprise.
High-protein diets: indirect proof
When you want to lose weight fast, what do you do? You turn to high-protein diets. These make you lose weight precisely because they are inefficient for our primate metabolism. They often rely on ketogenesis: you burn proteins and fats, leaving very little energy compared to what's required for digestion.
You lose weight because digestion consumes so much energy there's little left for the rest of your body. Including your brain. This explains why, after a day or two, high-protein diets start making you feel psychologically and physically terrible.
If you put gasoline in a diesel engine, great things don't happen.
The energy paradox
So how could a meat-based diet — which provides very little energy while greatly stressing the body — have been the basis for our brain's expansion?
The human brain needs enormous amounts of energy. It consumes so much that it uses cognitive biases as shortcuts to limit the most energy-intensive processes. Believing we developed by eating meat is clearly a stupid theory based on the opposite of self-evident reality. It's pseudo-science — like homeopathy.
Grains: the real answer
Research increasingly shows that — even before agriculture 12,000 years ago — our ancestors were avid eaters of wild grains and therefore carbohydrates. Thanks to fire, they could absorb them even better.
It's logical. Natural. Obvious. The simplest explanation, most aligned with how our primate bodies work. Occam's Razor in its purest form.
This doesn't mean ancestors didn't hunt. They hunted when they wanted or needed to supplement protein. But saying "we're smart because we started eating meat" is not the same as saying "we're primates, mostly vegetarian, who occasionally hunted."
The definitive test: other primates
We're a species that loves looking in the mirror and telling ourselves how smart and superior we are. But we forget we're just big apes with big brains in a family of big apes with big brains.
We have slightly more prefrontal cortex, but gorillas and chimpanzees have extraordinary spatial intelligence. Our entire primate family is on the big-brain path. Not just us.
Even if we were naive enough to believe meat-based evolution theories, we should immediately notice these are obvious nonsense since other primates also have large brains while being clearly vegetarian or near-vegetarian.
Our big brain is part of a "family" trend shared with similar species. A child would first ask what we have in common with our equally intelligent cousins — not what distinguishes us. Because what distinguishes us almost certainly can't be linked to what makes us similar: intelligence.
That would be a paradox. And perhaps that's why children can see it while we, with our hyperbolic human ego, cannot.
