"We Evolved to Eat Meat" so we should eat it
8 April 2026
The argument that we evolved to eat meat and therefore this is healthy for us feels intuitive and seems straightforward. After all, you need to be healthy to be fit and pass on your genes, right?
However, this argument is fundamentally flawed and based on misunderstanding. Evolution does not provide us with better individual health for two principal reasons: evolution doesn’t always optimize for health, and it didn’t operate in today’s environment.
For the quickest way to see an intuitive problem with this argument, consider that our ancestors evolved to digest alcohol about 10 million years ago [1]. If being evolved to consume something were good for health, alcohol should be very healthy to humans.
Optimization
What we evolved to eat is not necessarily what is healthiest, or even healthy, for us, as the alcohol example shows. One of the reasons for this is a subtle but important misunderstanding of what evolution optimizes for.
Evolution optimizes the passing on of genes. In many cases, this overlaps with healthy lives, yet in many other cases it does not. For example, Praying Mantis females often eat the male after mating. This works well for spreading the male’s genes, but obviously is not great for their health. The problem is that evolution doesn’t “care” about the males’ health once they mated. In humans, fathers are still evolutionarily useful even after birth to raise children. Here, both men and women lose most of their evolutionary purpose when their children can be independent instead. What we evolved to eat says nothing about our health after, say, 40 years old because of this.
Optimization by evolution also does not care about the individual. Bees famously defend their hive with a sting that kills themselves. This selfless sacrifice is great for the hive, but yet again, pretty bad for that individual bee’s health. In early human tribes too, evolution optimizes for survival of the species, not necessarily the individual. For your personal health, what we evolved does not necessarily predict what is good for us because of this group-selection.
So for good individual health beyond about 40 years old, evolution cannot be a good guide, because it never optimized for it.
Environment
In addition, the world looked very different during the time humans evolved to what it is now.
In that prehistoric world, fat and sugar were high in calories and hard to find. Calories were the main concern for our ancestors, not getting enough of them meant a tribe would die. In this context, it made sense that evolution made us enjoy these foods tremendously. This made early humans search them out whenever they could. Even when they were specifically looking for these foods, they were rare, so our ancestors didn’t often eat a lot of them. This is in contrast with today’s world, high fat and sugar foods are easy to find, yet still hard to ignore. Again, evolution optimized against personal health. For another example, take a look at bacterial infections. Evolution primed us to raise our body temperature and thus induce a fever to combat many of these. In some cases, the cure is worse than the disease, and the fever itself becomes dangerous. This may have been a valid tradeoff before, when without the fever the infection would kill us. Yet today very high fever can still cause lasting damage even though antibiotics remove the need for such high fevers. In these cases, because today’s environment is dramatically different from the one our ancestors lived in, evolution did not optimize for health today either.
Scientific Consensus
The above reasons show the argument that we should eat meat because of evolution is flawed at a principal and logical level. In addition, there are at least two empirical issues.
First, the scientific consensus is that there was no single ancestral diet, but rather a flexible pattern shaped by geography and season. Indeed some ancestors ate meat-heavy diets, yet others ate very little of it. This flexibility (further supercharged by cooking) allowed humans as a species to spread across the world, as omnivores in the broadest sense of the word, adopting their diet to whatever the environment allowed for. More recent studies have found that meat consumption of our ancestors has likely been overestimated before [2].
The second and most important, is about health outcomes. In the end, we care about what is healthy more than why that is the case. For this, we can ignore any mechanistic argument and instead look at what diets and foods provide the best health outcomes for humans. While perhaps hotly debated online, the scientific consensus is that high red meat consumption in particular is detrimental to health and processed meats are even worse [3].
Conclusion
The argument that we evolved to eat meat is fundamentally flawed, in the same way that we shouldn’t consume a lot of alcohol just because we evolved the ability to. Evolution has not optimized for personal health, and not for today’s world. On top of that, limiting processed and red meat, while increasing legumes, vegetables, whole grains, nuts, seeds, and some fatty fish shows better health outcomes [4].