No doubt you’ve heard of the “Palaeo” diet – also known as the “Stone Age” or “Caveman” diet. The idea is to eat foods available to humans during the Palaeolithic era (~2.5 mya to ~10 kya). The underlying hypothesis is simple: we should eat the stuff our species evolved eating. It wasn’t until the Neolithic period (beginning around ~10 kya) that we started relying on agriculture and farming. The Palaeo diet holds that one should avoid the more recent dietary additions – namely, grains, dairy, and processed foods. This diet packs a healthy punch of fruits and vegetables, wild meats, and healthy fats. Sounds pretty good, right?
Some people think not. The Palaeo diet has been criticised for its environmental impact (elevated carbon and water footprints), and for its high levels of saturated fats and cholesterol (Cambeses-Franco et al., 2021). These criticisms assume the Palaeo diet involves a lot of animal products – specifically, red meat. This is an oversimplification. During the Palaeolithic, humans dispersed throughout the world to inhabit a range of geographical locations. Subsistence varied hugely, and meat wasn’t a quotidian commodity for all populations.
Also, bear in mind that some animal products are easier to come across than others. We frequently overlook the contribution of insects to the diets of foraging populations. They’re a quality source of protein and easily attainable. Finding a bird’s nest and robbing the eggs is more likely (and less risky!) than finding a beehive and stealing the honey. Similarly, catching and collecting seafood is a lot easier than taking down a mammoth. Getting that big game red meat requires cooperation, planning, and skilled hunting – and there’s no guarantee of success.
Just look at modern hunter-gatherers. Some scholars estimate today’s warm-climate foragers average a 50/50% ratio of plant/animal foods (Pontzer and Wood, 2021). However, it is acknowledged this varies greatly. Some populations derive an estimated 85% of their diet from animal product; in others this drops to only 35% (Crittenden and Schnorr, 2017). Remember, modern hunter-gatherers are only a proxy for our Palaeo pals. Things have changed a lot over the past 10 ky and it’s doubtful any society is truly free from the influence of agriculture and pastoralism. Nonetheless, contemporary hunter-gatherers hint that prehistoric humans might have shown similar dietary variation. It seems pretty unreasonable to assume all Palaeolithic diets were intrinsically meat-heavy.
Another criticism of the Palaeo diet is how it is followed. Fenton and Fenton (2016) point out some people aren’t faithful to the fundamental principle: to make your diet as close as possible to that of prehistoric humans. Rather, they substitute modern Western foods with ‘Palaeo-friendly’ ingredients. Just like a person who only eats Oreos might claim to be vegan, someone who only eats honey and dried fruits might claim to be Palaeo. The bottom line here is how you follow diets. I find it hard to believe hunter-gatherers were eating honey every day; in nature, sweet treats play hard to get.
My real qualm with the Palaeo diet is recent human adaptation. The assumption that humans have not adapted to Neolithic foods is, in part, incorrect. Take, for instance, lactase persistence (LP). Baby mammals digest milk sugar thanks to the lactase enzyme, which breaks down lactose into digestible components. After weaning, the production of lactase usually ceases. Between ~5-10 kya, some of the human societies who were dairying co-evolved high frequencies of LP gene expression into adulthood (Segurel et al., 2020). Many populations in the world lack this adaptation and are subsequently lactose intolerant. Those who do have LP, however, might have been granted a selective advantage. Dairy products can provide a rich source of nutrients, such as fats, protein, calcium, and probiotics. The Palaeo diet’s major flaw, in my opinion, is that it does not account for adaptations such as LP.
Overall, I think there’s merit in following Palaeo principles. Eating a diet the human body evolved with seems like a good starting point. Perhaps a fully Palaeo diet isn’t the ultimate for your particular body, and you could benefit from the additional nutrients provided by post-Palaeolithic foods. A perfect diet for you might be very different from someone else’s; different populations can process the same foods in different ways. The critical thing is – as it is for many matters health-related – what you put in is just as important as what you leave out.