Paleo fact and fiction: The key to being healthy
Humans have conquered smallpox and drastically reduced child mortality rates, yet we now face problems never seen before. Conditions like heart disease, obesity, cancer, and diabetes pose serious threats to our health. How can we overcome them? The answer may lie in our past.
Herman Pontzer, an associate professor of evolutionary anthropology at Duke, thinks we have something to learn by looking at hunter gatherers.
For most of human evolution, we had to work for our food. Recent developments like supermarkets and cities are strange and have flipped the script on daily life. Pontzer believes if we could live more like our ancestors, maybe we wouldn't get sick.
Pontzer started off by studying a hunter gatherer group in Tanzania known as the Hadza. The Hadza cling tight to cultural traditions and live off the land in the African savannah. There are no domesticated animals, no guns, and no vehicles. Women spend their days digging for fibrous tubers and gathering berries and baobab fruits. When men aren't hunting game, they collect honey. Honey plays a major role in the Hadza diet—around 15-20% of their caloric intake.
The Hadza live a very active lifestyle. They walk between 13,000 and 20,000 steps a day, compared to the generic Fitbit goal of 10,000 steps (which most of us don't even meet, if we're being honest).
Curious to see if the Hadza's vigorous activity levels had something to do with their superior health, Pontzer used the doubly labeled water technique to measure total energy expenditure. Shockingly, he found that Hadza and Americans burn the same amount of calories on average.
All our lives we've been told exercise converts to burned calories. But evidence from the Hadza tells us this is not the case. What really happens is natural systems in our body adjust to suppress other activity, keeping total expenditure constant. This means that exercise alone is an ineffective tool for weight loss. But don't quit the gym quite yet—while the Hadza spend most of their total energy being active, an inactive body will spend it on unhealthy things such as inflammation and stress reactivity. This constrained energy mechanism makes exercise essential for overall health. But in the words of Pontzer, "in order to end obesity, we need to fix our diet."
The idea that the "paleo diet" is necessarily low-carb is a myth, Pontzer says. Hadza rely heavily on starches and fructose for sustenance. Furthermore, what you eat as a hunter gatherer is entirely dependent on geographical location. Hunter gatherer diets do things in common, though: they eat no processed foods, and energy dense foods are hard to come by.
Never before have we had so much food high in energy available at such a low effort. In supermarkets, the cheapest food is the most rich in energy. In the wild, it's the complete opposite. Pontzer says, "traditional diets are diverse, modern diets are perverse."
He calculated that an American can get twenty times as much food energy in an hour's work as a Hadza could with the same effort. Plus, the Hadza don't have irresistible Doritos they can't stop eating. When the Hadza are full, they're full.
The Hadza are naturally protected from the same "diseases of civilization" that we are likely to die from. A beautiful combination of diet and how they expend energy provides a shield that modernization seems to have taken from us. Energy has become too available. But staying healthy is still in our control. It's about finding the right balance of exercise and eating right.
There is still a lot to be learned from hunter gatherer societies. For now, let the Hadza inspire you to get outside, get active, and cut out processed foods!