Review - Hunter-Gatherers as models in public health

This study looks at the Hadza people of Norther Tanzania compared to large-scale (Western) societies and relative rates of obesity, cardiovascular disease, and physical activity regarding diet and lifestyle factors.

Image Credit: Dorobo Safaris

“Longevity among small-scale populations approaches that of industrialized populations, and metabolic and cardiovascular disease are rare. Obesity prevalence is very low (<5%), and mean body fat percentage is modest. Activity levels are high, exceeding 100 min / d(ay) of moderate and vigorous physical activity, but daily energy expenditures are similar to industrialized populations. Diets in hunter-gatherer and other small-scale societies tend to be less energy dense and richer in fibre and micronutrients than modern diets but are not invariably low carbohydrate as sometimes argued.”

Life expectancy (at birth) for the Hadza is low, 30s - 40s. However, this is due to a phenomena called “squaring of the morbidity curve” that conflates (average) adult lifespan with life expectancy (at birth). The later is disproportionately impacted by what I call “tiger problems” — acute trauma and infectious disease. Only about 60% of newborns survive to age 15 and 40% to age 45.

The authors note “A common misinterpretation of (life expectancy at birth) is to assume that few hunter-gatherers live to older age… adults regular(ly) live(ing) into their 60s and 70s.”

What about quality of life? Let’s look at some cardio-metabolic factors; the so-called “diseases of civilization.”

“Fewer than 2% of Hadza adults qualify as overweight (BMI 25 - 30)”, the average BMI being about 22 for both men and women. Obesity rates for men are about 1.2% and 4.6% for women. In the United States, the obesity rate in 2020 was 41.9% (ref.) — about 10x that of the Hadza.

As for Type 2 Diabetes (T2D), an estimated 0 - 2% of pastoralists are estimated to have T2D while in the United States (as of 2021) the rate of T2D is 11.6% (ref.) — 5x to 10x that of the Hadza.

The article reports that “more than 60% of US adults 60+ are hypertensive (have high blood pressure), while less than 30% of hunter-gatherers and subsistence farmers 60+ years show even mild hypertension.” The Hadza had an estimated VO2max of 56.7 for men 20 - 40 years old, which is higher than the average male UFC fighter (51, ref.).

Regarding general physical activity, the article cites a couple other studies reporting on other indigenous tribes who get about 6-9 hours of walking throughout the day, or 5.8 - 8.7 miles per day. That’s about 11,000 - 17,000 steps / day.

In the United States, the real “disease of civilization” seems to be that we stifle both activity and creativity; because people under 18 years old walk about 10k - 16k steps / day (ref.) while adult estimates are 5k - 7k steps / day (ref., ref., ref.). Fewer than 10% of Americans get the RDA of 150 minutes of exercise / week. That means people are moving less than 20 minutes per day, let alone 6 - 9 hours.

It’s also important to note that the Hadza sleep 5.9 - 7.1 hours / night. To me, that’s a significant indicator that “more” isn’t necessarily better, but that “better is better.” I’ve often wondered if it’s better to be knocked out cold for 6 hours straight, or be somewhat restless for 9 hours?

Further, the authors make an important note towards non-dietary habits that have long been understood as critical factors in the broadest sense of health beyond longevity.

“Finally, it is worth considering what other aspects of traditional lifestyles, in addition to diet and physical activity, might contribute to the remarkable health of hunter-gatherers. Close friendships and family bonds, low levels of social and economic inequality and lots of time spent out-doors are typical in hunter-gatherer populations and other small-scale societies. The absence of these in modern societies is associated with chronic social stress and a range of non-communicable diseases, including metabolic disease and obesity.”

Detailed discussion below…

Pontzer, H., Wood, BM, & Raichlen, DA. (2018). Hunter-gatherers as models in public health. UCLA. http://dx.doi.org/10.1111/obr.12785 Retrieved from https://escholarship.org/uc/item/1m87g85c

If you think it’s surprising that 20 years ago there was no:

• YouTube,
• Instagram,
• iPhone,
• Uber,
• Bitcoin,
• Netflix, and

…Facebook had just launched (2004), then you’ll be even more surprised at the following dates regarding food and “food-like products:”

• Impossible Foods, founded 2016
• Beyond Meat, founded 2009
• Vega, founded 2001
• McDonald’s, founded in 1940
• Oreo, founded in 1912
• Crisco, founded 1911
• Nestle’, founded 1905
• Pepsi Co., founded 1898
• Coca-Cola, founded 1886
• Slave-driven “Sugar Boom”, 1710

It’s interesting to see that “meatless” companies have only become noteworthy in the past 20 years. Of course, there were vegans before this, but for the time being let’s ignore the obvious tangent of medical “misinformation” and public sway and propaganda of Harvard, WEF, etc.

We can see that, in addition to “meat imitation foods” only being about 20 years old, “fast food” or vegetable-oil laden food is about 100 years old and globalized trade and mass production of sugar is about 200 - 500 years old.

Let’s recap then:

• “meatless” meat: 20 years old
• “fast” food / vegetable oil: 100 years old
• mass produced sugar: 200 years old
• coffee: 600 years old

To put things in perspective, let’s scale this by a few orders of magnitude:

• “meatless” meat: 20 years old
• coffee: 600 years old
• chocolate (unsweetened): 5,000 years old
• domesticated agriculture and livestock: 12,000 years old
• gathering wild grains: 100,000 years old
• hunting wild meat: 2,000,000 years old

In other words, Homo Sapiens have been eating wild meat for longer than we’ve been our own species — 100,000x longer than “meatless meat.” Somehow our species spread to every continent on the globe (except Antarctica) in a mere 70,000 years and our brains doubled in size over a cool 1 million years by eating “the foods that are (allegedly) killing us” — meat.

Jumping back to the future, the authors of this article also note that “The hypothesis that industrialized populations are prone to metabolic disease be-cause they are less active and therefore expend fewer calories per day is not supported by metabolic measurements from hunter-gatherers and other small-scale societies.”

If hunter-gatherers are consuming similar amounts of calories as “diseased” (i.e. industrialized) civilizations, this greatly discredits the idea that “all calories are created equal.” Ostensibly one could fall in to the trap of “calories in vs. calories out” (CICO), but again this only tells part of the story. Though, to play devil’s advocate, I highly doubt that anyone who says “calories don’t matter” has ever seen 5% body fat for themselves.

That brings us to two points of contenti:

• Activity, and
• Calorie composition (e.g. macronutrients)

We’ve already discussed, as it is no secret, that American’s (and the industrialized world as a whole) are grossly inactive, un-fit. For years I have told people “abs are made in the kitchen.” Simply put, for the average exerciser (note the difference between exercise and training) the 30-60 minutes you spend in the gym is fraction of the calories you expend throughout the day.

Therefore, exercise is a relatively inefficient way to expend energy. Our bodies are made to move and to do so efficiently in terms of energy. Of course, there’s a myriad of benefits to exercise. It just seems more efficient to put the fork down a little sooner than to run a few more miles.

Do you know what 600 calories of output — not metabolic expenditure, work output — in an hour feels like? If not, that Starbucks milkshake you’re telling yourself is “coffee” is costing you a lot more than a few bucks.

While we’re talking about work output, let’s cite the article authors again; “among the Hadza, Marlowe and colleagues have estimated that honey accounts for ~15% of energy, ranging monthly from 1% to 50%.”

I will have a 2-month post series coming out soon on “what I eat in a day.” I can assure you my carbohydrate intake is nowhere close to 50%. I can also assure you that on a barn-burning Saturday where I roar through 5,000 calories, or thinking back to long days in the mountains (maybe 8,000 - 10,000 calories), macros seem to matter a lot less.

“Meat-heavy, low-carbohydrate diets may have been the norm for some hunter-gatherer populations in the past, but many small-scale societies, including those with excellent metabolic and cardiovascular health, eat diets that are relatively rich in carbohydrates and (via honey) simple sugars.”

In other words, counting, or worrying about macros is a privilege; a literal first-world problem. Whether it’s the Inuit or the Hadza, they’re not contemplating “optimal ketone levels” or autophagy or mTOR. They’re eating what’s available and not going to kill them.

Most people, including myself on most days, aren’t “earning your carbs.” With that said, and in conjunction with the above timelines, it should be quite clear that moving a lot, forming strong social and community bonds, having a sense of purpose (outside of and within yourself), and eating a lot of meat are all extremely conducive to a healthy and fulfilling lifestyle.