Evolutionary Arguments For Your Diet Suck | Vol. 3 / No. 36.3

A food pyramid | Photo: bigbrand, CC BY 2.0

It seems like everybody these days thinks they can justify their particular dietary choices by citing evolution. The “paleo” diet eschews dairy and grain products because in theory we wouldn’t have had those at some indistinct historical point. Some vegan diet proponents use a similar logic, arguing that we don’t have the incisors for meat eating, but also failing to notice that we also lack the multiple stomachs and regurgitative digestive practices of strict herbivores as well (thank god — call me crazy, but the idea of chewing my cud doesn’t sound great to me). So-called “raw foodists” argue (I can only assume) that fire is unnatural, so therefore cooking our food must be as well.

Look. Everyone. I’m only going to write this once, so read carefully: this is a terrible argument for picking a diet.

No, I lied, I’m going to write it again: this is a terrible, terrible argument for picking a diet.

The modern North American diet isn’t great. By and large we eat too many calories, we don’t eat enough fibre, and we’re most of us pretty short on at least some important vitamins and nutrients. We also have a lot of heart disease and diabetes in the population, both of which are probably (though maybe not certainly) tied to our sugar- and saturated fat-rich diets.

And it’s nothing to do with our diets, but we also don’t exercise as much as we should (or, hell, even move as much as we should — I mean come on, who here hasn’t spent an entire weekend on the couch binging two whole seasons of something bland while mindlessly eating junk food and deliberately avoiding looking at their fitbit for fear of the massive wave of self-loathing that they know would wash them into a sea of despair if they made the mistake of even taking a peek? …just me then? Okay.)

But all that said, we don’t, like roughly 40% of the children in this world who die under the age of five, suffer from complications of vitamin A deficiency. We’re taller than ever before, because we’re better fed. Worldwide hunger is dropping (even if there’s more work to do to get to zero).

Basically, our modern diet doesn’t totally suck.

But seeing as it isn’t perfect, we keep trying to improve it — cutting out too much refined sugar, maybe, or giving up on that pound of bacon you eat every week you fabulous glutton, you. There are dozens of perfectly good reasons to try to adapt your diet, but none of those reasons are “because we didn’t evolve to eat that.”

Humans evolved to eat damn near everything we could get away with. Hell, we couldn’t even digest dairy for most of our history, but enough of us kept shoving it in our mouths over time that eventually the few freaks who could still digest it after puberty ended up with more kids than the rest, and the ability spread. In fact, we even went through that process twice! Why? Because being able to eat anything and everything is a hell of a way to stay in the game when the game is “eat well to live longer and have more kids.” Food sources come and go, and if you can eat all of them, you stand a higher chance of winning. We have super expensive brains (calorically… I’ve never tried to buy one. Don’t look at me like that) and eating meat might even have been the thing that got them for us. Cooking our food definitely frees up more calories so that probably helped with the brain thing too.

Long story short: we grew up on a planet where being able to eat everything from seeds to bugs to “that stuff that baby goat is sucking out of its mother” to “that thing with sharp teeth you accidentally killed after it made a run at you while you were holding that big stick” — being able to eat all of it was an advantage. And taking advantage? That’s at the heart of human evolution.

Now, does that mean anything for what we should be eating today?


There’s a ton of science out there trying to determine what we should and shouldn’t be eating. Some people think if it’s the least bit possible for us to survive on a diet of only plants, then that’s the only ethical option. I’m not going to debate that (though others will). Some people say eating only raw meat makes them feel super great. I’m not going to make judgements about that either (you do you, raw meat guy, you do you).

Literally the only point I’m getting at with this absurd (and hopefully a little entertaining) post is just what I said at the top: don’t use evolution as support for your particular diet of choice, unless your diet is “I can get away with making choices about what I eat most of the time,” because that’s the long and short of what evolution has had to say about the human diet.

Now go decide what to eat for dinner; all this reading’s making you hungry.


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Richard Ford Burley is a human, writer, and doctoral candidate at Boston College, as well as an editor at Ledger, the first academic journal devoted to Bitcoin and other cryptocurrencies. In his spare time he writes about science, skepticism, feminism, and futurism here at This Week In Tomorrow.