Is there an ideal diet for humans? The idea that the way people ate in the past was better and more health promoting than our modern diet is attractive. The paleo diet, for example, is based on the idea that our ancient ancestors were healthier than we are. It's also a common bit of folk wisdom; our great-grandparents' generation didn't suffer from obesity and diabetes, we reason, so their diet must have been better.
A fascinating study was published last month in the journal Obesity Reviews, which takes a deeper look at how hunter-gatherer populations live and eat, and how that affects their health - both in the past and in those populations still living this way now.
The researchers found some really interesting things. Firstly, hunter-gatherer populations were, and are, seriously healthy by today's standards. Discounting deaths from accidents and infectious diseases - things that happen when you're living in the wild - they tend to live just as long as we do.
But they suffer from very, very few of the modern diseases that are killing us. Type 2 diabetes is so rare, according to the researchers, that it was hard to find reports of it at all. Obesity is also rare. Among the Hadza, a hunter-gatherer community in Tanzania, fewer than 2 per cent of adults is overweight. And heart disease is almost non-existent, too, accounting for "a negligible proportion" of deaths, even in those over 60.
So what can we learn from hunter-gatherers to help us become healthier?
In terms of diet, the researchers say, there's no one answer to that question. What hunter-gatherer populations eat - and most likely ate in the past, too - varies so widely that, they say, "the idea that there is one true, natural human diet to which we might all aspire is negated by the incredible variety of hunter‐gatherer diets recorded by early ethnographers and researchers today".
Many populations eat, for example, high amounts of carbohydrates as staple foods. "Meat‐heavy, low‐carbohydrate diets may have been the norm for some hunter‐gatherer populations in the past", say the researchers, "but many small‐scale societies, including those with excellent metabolic and cardiovascular health, eat diets that are relatively rich in carbohydrates and (in the form of honey) simple sugars".
What hunter-gatherer populations have in common, though, is that they all eat a mix of plant and animal foods - no vegans here - and they do not eat any highly processed foods. They might be eating carbs, but they're in the form of tubers, not Twisties.
They also notably have high levels of physical activity; hours a day in many cases, often at low-moderate levels of intensity. Interestingly, this doesn't necessarily mean they expend more energy than we do - but it's still associated with their remarkable health.
Also worth noting: the other aspects of hunter-gatherer societies which we also value, and contribute to better health: close friendships and family bonds, low levels of social and economic inequality and lots of time spent outdoors.