Those sluggish hunter-gatherers
Can this really be true?:
The research team behind the study, led by Herman Pontzer of Hunter College in New York City, along with David Raichlen of the University of Arizona and Brian M. Wood of Stanford measured daily energy expenditure (calories per day) among the Hadza, a population of traditional hunter-gatherers living in the open savannah of northern Tanzania. Despite spending their days trekking long distances to forage for wild plants and game, the Hadza burned no more calories each day than adults in the U.S. and Europe. The team ran several analyses accounting for the effects of body weight, body fat percentage, age, and gender. In all analyses, daily energy expenditure among the Hadza hunter-gatherers was indistinguishable from that of Westerners.
I do remember learning, back in anthro classes long ago, that many hunter-gatherer groups actually don’t have to use a whole lot of energy to get their food— certainly not as much as one might think—and that it was only with the advent of agriculture that the really grueling work began. Hunter-gatherers tend to expend a great deal of energy in spurts, with a lot of resting in-between.
But still, Westerners today seem to be such relative couch potatoes that it’s difficult to believe that the Hadza can expend the same amount of energy and live, unless they happen to be sitting in the middle of the Garden of Eden. The article is a bit murky as to the mechanism by which this human conservation of energy is accomplished, because it indicates that the Hazda do spend more of their daily energy needs in performing physical activity. So, what makes up the difference? Do the more lethargic Westerners have a higher basal metabolism? And if so, why? Does the body have a sort of homeostatic mechanism in terms of energy needs?
It doesn’t make much sense to me, but there’s an awful lot we don’t know about these things—including the fact that this study might be incorrect, or the Hazda might be atypical.
After I wrote the above, I got curious about the Hazda, and found this National Geographic piece with the following passages:
The Hadza diet remains even today more stable and varied than that of most of the world’s citizens. They enjoy an extraordinary amount of leisure time. Anthropologists have estimated that they “work”””actively pursue food””four to six hours a day…
The things they own””a cooking pot, a water container, an ax””can be wrapped in a blanket and carried over a shoulder. Hadza women gather berries and baobab fruit and dig edible tubers. Men collect honey and hunt. Nighttime baboon stalking is a group affair, conducted only a handful of times each year; typically, hunting is a solo pursuit…
People sleep whenever they want. Some stay up much of the night and doze during the heat of the day. Dawn and dusk are the prime hunting times; otherwise, the men often hang out in camp, straightening arrow shafts, whittling bows, making bowstrings out of the ligaments of giraffes or impalas, hammering nails into arrowheads.
Quite a few hints there.
[Hat tip: Instapundit.]
“Hunter-gatherers tend to expend a great deal of energy in spurts, with a lot of resting in-between.”
Hey, they’re just couch-potatoes with no couches.
What are their rates of obesity? According the the primal lifestyle folks (Think Mark Sisson) they should have lower rates of obesity, longer lifespans, fewer problems with “modern diseases” like diabetes, hypertension, cardiac disease, etc.
That would interest me. He (Sisson) says that diet is more important for staying thin than exercise.
Will: my impression is that their rates of obesity are low, and my guess is that they don’t have high rates of those diseases or syndromes. However, I’d also guess that far fewer of them live to old enough ages to exhibit the high rates of those illnesses that show up in the Western world with increasing age. What’s more, those among them with the weaker constitutions and the great susceptibilities to illness in general probably are the ones who die out at younger ages.
Brains require a lot of energy to fuel.
So do muscles.
I bet that hunter gatherers are more physically active than I am.
Sounds like Darwin at work…
From Genesis:
“[17] And to Adam he said, “Because you have listened to the voice of your wife,
and have eaten of the tree
of which I commanded you,
`You shall not eat of it,’
cursed is the ground because of you;
in toil you shall eat of it all the days of your life;
[18] thorns and thistles it shall bring forth to you;
and you shall eat the plants of the field.
[19] In the sweat of your face
you shall eat bread
till you return to the ground,
for out of it you were taken;
you are dust,
and to dust you shall return.”
“After I wrote the above, I got curious about the Hazda, and found …”
Yes, speaking of which, you might have been following this story, but not realized that the Hadza were one of the population groups included.
http://dienekes.blogspot.com/2012/07/new-evidence-for-archaic-admixture-in.html
http://dienekes.blogspot.com/2012/08/gilbert-on-erectus-klein-on-sapiens.html
As I was completely unfamiliar with them I went to Wiki, and what I read of their oral tradition left me blankly staring at the screen for some moments as I tried to calculate whether it was completely absurd to think that some kind of event tradition, or oral memory could possibly … well, I concluded that it was absurd.
I have no family tradition memorializing Neanderthals. I guess.
Also, perhaps less relevantly, since it may not be the same population showing Archaic Human admixture, http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.0020105
“While the putative source population may not be as obvious as in Europe (Neanderthals), the fossil record shows that transitional forms of Homo were widespread in Africa, even after the time of emergence of modern humans. Other genetic studies have also found evidence for ancient structure in African populations [28—30]. In two of the three studies [28,30], the divergent lineage was found only in Pygmies, which suggests that the African population source differs from the European one.”
Going native was a real problem for the New England colonists. The Indian lifestyle was extremely appealing, especially for the young men. Oddly enough the Indians weren’t particularly interested in becoming civilized and living like the colonists. It was an even bigger problem in “New France” which was structured like the court of Louis XIV and very heirarchical. The young men prefered the free and easy ways of the natives. They also ate better than the French.
The answer is simple and explained more than 30 years ago by Dr. Robert Atkins. The problem is truly carbohydrate intake. Stop eating all those grains, and fruits and a lot of high sugar vegetables and watch the pounds drop. The problems all started with the food pyramid.
Paul in Hartford:
No. They. Do. Not.
For some people, yes, but not for others. Like me, for example.
And one other thing, as many people who do the same exercise routine over and over have learned: if you don’t change it up, do something different, your body eventually accustoms itself to that particular workout, and stasis sets in. You might not put on weight, but you don’t lose any either, nor put on muscle. Walk-stalk-throw spear (or shoot arrow)-recover prey-eat-sleep. Maybe it’s become a routine enough “workout” for the Hazra that their calorie expenditure has stabilized. For a group of people like the Hazra, who have low obesity and all the muscular strength they need, this is probably not a bad thing.
But it must be a nuisance to carry around those reels of cable so they can watch Survivor and catch the latest native documentary on WGBH.
I’m a little late to this conversation but….
@Paul. The Hadza diet is primarily carbohydrate. Atkins was wrong. His theory was total garbage, all metabolic ward studies prove that weight is a factor of calories in, calories out.
@Neoneocon: Re: obesity rates among the Hadza – read the original study. A table gives their weight. They are skinny as hell.
Also, about anthro class and the ‘leisure society’ of hunter-gatherers – this is an exaggerated claim. It’s true of some groups and not of others.
But this study is an eye-opener.