Study finds hunter-gatherers' energy expenditure same as modern Westerners' | Hacker News Reader

Study finds hunter-gatherers' energy expenditure same as modern Westerners'

nytimes.com

65 pointsgeorgecmu30 comments

Modern food can be so fantastically calorically dense that it's depressing to sit down (ha!) and compare food taken in versus the amount of exercise one can reasonably perform. Anybody who has ever done so will have immediately realised how much pedalling a slice of pizza or a donut can be equal.

You may have heard that "abs are made in the kitchen", or "you can't outrun the fork". And this just shows that it's true even for very physically active people.

I train in Olympic-style Weightlifting, probably one of the more demanding physical activities. Elite international-level athletes in Weightlifting can be visually categorised into two groups: superheavyweights and everybody else.

Why? Because superheavies don't need to make a weight class, there is no incentive to strip down fat. So they eat heavily to support maximal hypertrophy and training intensity.

Whereas weightlifters trying to squeeze in at the top of a weight division will often have very low bodyfat. How is this achieved? Through a tightly controlled diet.

We are talking about athletes who in all other respects train the same way. A Chinese superheavy trains the same way as a Chinese welterweight. A Bulgarian superheavy, same as a Bulgarian heavy. And so on. Literally every day, racking from hundreds to thousands of calories of exercise. But they eat differently.

And the results speak for themselves.

>>>>"Of course, if we push our bodies hard enough, we can increase our energy expenditure, at least in the short term. But our bodies are complex, dynamic machines, shaped over millions of years of evolution in environments where resources were usually limited; our bodies adapt to our daily routines and find ways to keep overall energy expenditure in check."

And yet how do we get from a modern man spending most of time sitting down spending the same energy as a Hadza walking ~100 miles a week to a modern Olympian swimmer supposedly spending 12,000 a day and maintaining 8-10% body fat while swimming 50 miles a week? Does 10+ years qualifiy as 'short term'?

http://www.michaelphelps.net/michael-phelps-diet/

I think that the NYT article was poorly written.

It's hard to tell what was meant by controlling for differences.

For example, fat people have a higher BMR, simply because they are larger.

Tall people have a higher BMR, because they are larger.

And so on.

The "Phelps diet" is a bit of a media beatup, apparently. Not that it matters, Phelps could still get fat if he wanted to. Elvis is estimated to have been eating more calories than that in the year before his death.

I personally hung out with the Hadza for a few days a little over ten years ago.

This article rings completely true -- most of them really only spent a couple hours a day "working", which is typical of hunter-gatherer tribes -- it's remarkably leisurely. People didn't break their backs working until the agricultural revolution, which demanded it.

The Hadza spend a ton of time "gambling" amongst each other, which doesn't involve a lot of energy. And even while the article says:

> Each day the women comb miles of hilly terrain, foraging for tubers, berries and other wild plant foods

It's really not a big deal. It's like walking around Central Park a bit. And the East African savannah is a really flat place, the hills are not big. It's just leisurely strolling around, nobody's in a hurry. The annoying part is digging for roots with sticks.

Fun fact: in Africa, the hunter-gatherer tribes are the only tribes with no history of famine.

Anec-data: with no other changes to the amount I work out (a lot), how much alcohol I drink (I don't), or really the amount of food I eat (6 small meals a day), weight just started falling off when I stopped eating sugar in the form of cakes, candy, and donuts. Also my skin cleared up, and my eyes stopped being shot.

My (far from proven) theory is that refined sugar in enough quantity to give you a slight buzz is the almost sole factor in weight gain in many individuals.

How about sugar from soda?

Isn't that exactly what he/she said?

To be fair, OP said 'sugar in the form of cakes, candy, and donuts'. Also, sodas are a special case, as they have pretty much zero nutritional value and, unlike solid food, do nothing to fill you up.

So you're arguing that it was an even worse question than I hinted at? ;)

No sugar from soda... I've drunk diet soda as long as I can remember. My belief is that anything with significant sugar in is highly addictive; I've got a very very addictive personality, and have never felt remotely addicted to soda, but have also only ever drunk diet soda.

If you consumed the same amount of food, how did you substitute the sugar you took away? Sugar has a lot of calories per weight, if you simply reduced the calories intake then losing weight isn't unexpected.

They said amount, not 'calorific value'. Penhaps it was replaced with lower calorie food. But i think there is also the factor that sugary foods/carbs are more addictive and not as satiating as fatty foods (eg 'i'll just have another biscuit', cf. considerable successes of keto diets).

Eating something less sugary may have had a knock on effect and reduced the amount of food eaten later.

I ate until I was no longer hungry, just not sugar. Did I eat fewer calories? Almost certainly. Did I go hungry, or feel like I was eating less? Not at all...

I think it's pretty safe to say then that the weight just started falling off because you were taking in less calories. That'll happen. I don't think there's any reason to assume that the same thing wouldn't have happened if you had cut out fats or protein instead.

Sure there is. If you cut out protein, and eat chips or cookies whenever you are hungry, you will eat a lot more calories total, because you will feel less full.

There is a massive difference in the ability to satiate of fat and protein vs sugar.

Google keto diet.

Dr. Lindeberg and co. found the same thing (albeit using less sophisticated methods) in the study of the Kitava islanders more than 20 years ago.

http://www.staffanlindeberg.com/TheKitavaStudy.html

I lost about 70 pounds without working out. Just moderating my diet.

I lost 44 pounds by drastically cutting out sugar ... no more junk food, sweats, beer, sodas or sugar in my coffee. The only sugar I get these days is from fruits and milk.

This closely matches my experience. You don't even have to be too precious about it though: I'll still put half a teaspoon of sugar on my (sugar-free) cereal in the morning, and I don't feel I'm hurting myself...

I got married a few months back, and decided to eat sugar again from the day before the wedding until the end of the honeymoon. One week in to the honeymoon I'd noticeably gained weight, so cut it out again for the second week ... and ended up only half a kilo heavier at the end.

Ditto. I lost about 40 lbs cutting out snacks at all, and sticking to highly regulated meals (high in protein - not carb-less, general caloric restriction, avoidance of processed high-fat foods like most sauces, dips, etc).

And then I gained 30 lbs of that back by moving to a new city and letting myself go. Physical activity did not really change.

What goes in has way more to do with your weight than what goes out.

I used to really tightly regulate everything I ate, and stuck to that as a bit of a crutch, and like you would gain it all back when I stopped. Since I've stopped allowing myself any candy (or candy-like things), I've been able to be pretty chilled out about what else I eat... Also: I weigh myself every day, and plot it, which helps me get back on track if I'm starting to creep up, and need to eat just a little less

More anecdata, from me and my wife: losing weight is easier in periods of reduced exercise (although we're both in excellent shape normally).

My suspicion: heavy exercise gives you a hunger response in excess of the calories you've burned. That said, I've been told your basal metabolic rate goes up with the more muscle you have.

Same here. Lost ~44 pounds without exercising. I just take a 10-15 minute walk 3-4 times a week and removed most of the processed foods from the diet, no meat, no eggs, very low sugar, became a vegetarian. So most of the impact came from changing my diet and not merely from exercising.

Good books on diet:

In Defense of Food, Michael Pollan

What To Eat, Marion Nestle

Eat, Drink and Be Healthy, Walter Willett

Mindless Eating, Brian Wansink

Why We Get Fat, Gary Taubes

>> We think that the Hadzas’ bodies have adjusted to the higher activity levels required for hunting and gathering by spending less energy elsewhere.

When I commute by bike, my brain is less flexible at work, than if I tube it in and eat chocolate. I will happily agree that my body shifts from using the brain at 100% CPU to 50% CPU and 50% body.

That big lump of grey matter does not run 100% all the time.

Also: glucose helps self discipline.

The article says hadza walk many miles per day but burn the same calories as sedentary westerners. How is this possible? Well you go look at the table in the study and the hadza are all 30kg lighter than westerners. The men are all apparently 5'4 and 115lb, if you look at the BMI. That's probably 115lb at sub 5% bodyfat, too.

The study claims to control for body size. I didn't read it. But I still suspect we're looking at an apples to oranges situation here. A little dude of pure muscle who has been walking 10 miles a day his whole life is essentially incomparable to a fat sedentary Westerner.

I don't think the data presented predicts that if you had 6' fat sedentary people walk three miles a day they wouldn't lose weight, but that's almost claimed in the article.

Obviously, if you had a 6' fat sedentary person suddenly start walking 3 miles a day, they would lose weight. That's actually -not- the claim of the paper. The paper claim is that total energy expenditure is largely uncoupled with physical activity levels. For example, within the Hadza they found no real difference in energy use compared to different amounts activity. They also found no relation between body fat percentage and total energy use.

What this points to is that if you give the human body time to adapt to any set of conditions, you'll likely end up burning roughly the same amount of calories.

Here's the actual paper by the way: http://www.plosone.org/article/info%3Adoi/10.1371/journal.po...

The gist of the article is this: the reason people are fat today is not because they burn fewer calories per day. In fact, they burn the same amount as hunter gatherers. Thus, the reason people are fat today is because they consume more calories per day.

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