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Scarlet Ibis
08-14-2012, 04:00 AM
A new study suggests sedentary office workers burn just as many calories as hunter-gatherers.

Sad news for me, since I've been trying a new exercise program to burn off belly pooch, and tone up. I'm not going to stop, but I have to say I always thought the rule that exercise is necessary along with diet was clear-cut.


Read the full Atlantic article here (http://www.theatlantic.com/health/archive/2012/07/study-office-workers-burn-as-many-calories-as-hunter-gatherers/260384/)
Read the full study here (http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0040503#s1)


http://www.plosone.org/article/fetchObject.action?uri=info:doi/10.1371/journal.pone.0040503.g003&representation=PNG_M


PROBLEM: The equation is simple enough: Consume more calories than you burn off through physical activity, and you will gain weight. As such, the largely sedentary nature of the Western lifestyle is often blamed for our culture's rising levels of obesity. How legitimate is this claim, and do we desk-workers expend significantly less energy each day than do those who lead more "traditional" lifestyles?

METHODOLOGY: The Hazda, a hunter-gatherer population in Northern Tanzania, were used as a modern manifestation of the foraging lifestyle: they procure their food without the help of modern instruments and do not consume processed foods. Using wearable GPS devices, portable respirometry systems, and urine tests, researchers tracked the Hazda's daily walking distances and measured their energy expenditure when walking and resting. This data was compared both to individuals and to populations, comprising Western, market, and farming economies.

RESULTS: As expected, the Hazda were, on average, much more active than members of Western society. But in a surprising twist, there was no significant cross-cultural difference in total energy expenditure between people of similar age and body composition, at least partly because we burn more calories just sitting around than do the Hazda.

CONCLUSION: Lifestyle was not shown to be a contributing factor to one's total daily energy expenditure. In fact, total energy expenditure is remarkably consistent across global cultures and economies, and is perhaps "more a product of our common genetic inheritance than our diverse lifestyles." So whether you are hunting down and killing your dinner yourself or grabbing take-out after sitting in front of a computer all day, the calorie intake needed to supplement your energy expenditure is more or less the same.

IMPLICATIONS: With differences in energy expenditure taken out of the above equation, these results seem to indicate that it's increased calorie consumption that is contributing to obesity (supersized soda, anyone?).

Azvarohi
08-14-2012, 05:17 AM
but I have to say I always thought the rule that exercise is necessary along with diet was clear-cut.


Not the rule, but the ideal. Weight loss is achieved through negative energy intake, thus you can loose weight just riding the bed if you adjust your energy intake to it. However physical exercise have many superior qualities; for starters you use up more energy, which means you can eat more (which is almost vital if you want to have a normal life and also secure micro-nutrient intake through food rather than supplements). Secondly, physical exercise is health beneficial. Obese men who exercise are less likely to get diseases associated by metabolic syndrome compared to normal weight sedentary men.

Arbogan
08-14-2012, 12:40 PM
I don't buy into this study.. working out intensively does increase metabolism. I've lost weight through conventional cardio, while not changing diet, the only difference is that you have to workout intensively for longer intervalls to speed up metabolism and eat more. Metabolism isn't entirely genetic like this study seems to imply.

Verj-nu-armu
08-14-2012, 02:11 PM
Working out does increase metabolism. But if these hunter gatherer mainly walk, how much, 1 hour, 2hours? Then it of course will not have much of a impact. Walking is notoriously energy efficient.

So yes 2 minutes abs or taking a half an hour walk has little effect if you want to loose weight. But working out in the level some of the top athletes in biking, swimming etc do, then it certainly has effect. You can see this on the calorie intake on some of the top athletes. They can eat 3-4 times the calories recommended for normal person, yet they are incredibly slim.

So yes light exercise has very little effect, but it's wrong to say imo that exercise doesn't help with weight loss. It does when your spitting blood.:amen:

History-of-Things
08-14-2012, 02:55 PM
I do not know about the Hazda. Hunter-gatherers can walk a vast range--some do a bit every day (say 12 km), and others can be idle for days and then go on long (scores of km) treks. Certainly many, maybe most, will walk much more than two hours a day, depending on the environment in which they function.

DMXX
08-14-2012, 03:24 PM
I actually do see a correlation if one separates the women (empty circles) from the men (full circles) in every group. Each gender curves slowly to the bottom-right as one goes further down, more or less. This is particularly evident among the Western, Hunter-Gatherer and Farmer men, presumably because the burden of physical work is on them?

You'll notice that the men are generally leaner than women. This is physiologically normal given the effects of sex steroids on their bodies (i.e. androgens and oestrogens).

vineviz
08-14-2012, 04:02 PM
The authors of the study suggest that exercise DOES help with weight loss.


Physical activity has important, positive effects on health [39], and increased physical activity has been shown to play an important role in weight loss and weight-maintenance programs [40].

However, they do observe (and the main focus of the study is on this point) that increased activity levels are unlikely to lead to weight loss if there is an accompanying increase in caloric intake.

GTC
08-14-2012, 04:41 PM
The authors of the study suggest that exercise DOES help with weight loss.

However, they do observe (and the main focus of the study is on this point) that increased activity levels are unlikely to lead to weight loss if there is an accompanying increase in caloric intake.

Spot on.

When I attended gym daily, I was toned but I had a voracious appetite to match it. When I weened myself off gym the appetite remained and I put on a lot of weight accordingly. I've seen the same thing happen to guys I know.

And when I worked in an office I sat for most of the day but I was also up and down to the printer, the john, the coffee bar, to meetings on different floors and offices and I walked to the train and back from my car which was parked a few blocks from the station. So I walked a few miles a day on the job.

Sitting around merely vegetating is a recipe for disaster down the track.

God Child
08-15-2012, 08:00 PM
Seriously... I think the writers/researchers write such articles to get attention/attract readers/etc. Anyways... the calorie intake + source of calories differ between office workers and hunter-herders. Betty in the office is snacking on brownies, cookies, and chips all before she heads out to for lunch at a local burger joint... The Hazda people are only eating berries, nuts, honey and occasional wild game. If I'm not mistaken, metabolism is also effected by time intervals between meals/etc. Since food resources arent as abundant, it would make sense for the body to conserve energy and not increase metabolism (probably the case w/ Hunter-gatherers) in comparison to individuals eating around the clock (sedentary office worker).

utR!
08-19-2012, 06:41 AM
It is emphasized lately that loosing weight is more effective when eating less calories, carbohydrates, increase vegetable and fibre good fat and so on. It is a boom to eat mostly protein and fat and veg. I know one who lost most of hair and still keep on this diet and do not exercise and also is smoking and have symptoms of claudicatio. For all this kind of diet does not suit.

When I was much younger I wanted to loose weight by walking quite a lot daily, eating much less and taking multivitamin tbls. In 2 months I lost 8 kg.

For some it needs to reduce fat for some carbohydrates. I think you do need some exercise too (after it you do feel hungry :).

tuuli

AJL
08-19-2012, 04:56 PM
Something very few people mention in weight loss is the importance of sleep. If you have decent muscle mass and metabolism, you will burn fat as you sleep, and if you sleep eight hours a night, you will burn a lot more than if you sleep five.

There are also both autosomal and mitochondrial mutations that can affect how one's body makes use of food energy.

utR!
08-19-2012, 05:38 PM
Something very few people mention in weight loss is the importance of sleep. If you have decent muscle mass and metabolism, you will burn fat as you sleep, and if you sleep eight hours a night, you will burn a lot more than if you sleep five.

There are also both autosomal and mitochondrial mutations that can affect how one's body makes use of food energy.

AJL, I have read about it and maybe there is a decent study somewhere. It so usual that a lot of people (working) do not sleep enough. Also after exercising your body still burn fat (you should eat much after an energetic physical training.

P. s. I may have those mutations who knows. :eek: :eek:

tuuli

AJL
08-19-2012, 06:27 PM
P. s. I may have those mutations who knows. :eek: :eek:


Finns generally are a bit more hunter-gatherer-like than most other Europeans and it's certainly possible you have some of these mutations autosomally.

I don't know if there are any mutations in H1 that may commonly affect metabolism. My father is H1, and his maternal aunt did have Type 2 diabetes, but I won't assume these were causally correlated and in fact this seems to have been more a lifestyle issue. In fact, almost every one of his H1 relatives has had a very long life, with his grandmother and most of her sisters living into their 90s.

utR!
08-20-2012, 02:06 PM
Finns generally are a bit more hunter-gatherer-like than most other Europeans and it's certainly possible you have some of these mutations autosomally.

I don't know if there are any mutations in H1 that may commonly affect metabolism. My father is H1, and his maternal aunt did have Type 2 diabetes, but I won't assume these were causally correlated and in fact this seems to have been more a lifestyle issue. In fact, almost every one of his H1 relatives has had a very long life, with his grandmother and most of her sisters living into their 90s.

That's right there were and are dibetes type 2 in my mother's close and a bit distant relatives. I think I have never heard that there is diabetes in my father's relatives, more cancer like that. Is it the H1 only or other H1a, b and so having perhaps mutations? Does it come so far from H1?

tuuli

basque
08-20-2012, 08:16 PM
Some people go to the gym often and put in the minimum effort and remain over weight. I call these people energy conservers perhaps they would be better joining the sweaty minority of energy burners.

basque:boxing:

Artemis
08-20-2012, 11:01 PM
The other thing is one can assume the Hazda are not overweight, yes? What about the office workers used for the study, are they overweight or do they have a "normal" BMI?
Additionally, I thought that effective weight loss methods varied depending on certain genetic factors which differed from one person to an other. I remember reading about the Hazda people, who've remained this way, in this lifestyle for millenia wouldn't their energy expenditure and calorie intake be optimal for that lifestyle?

AJL
08-21-2012, 12:44 AM
Is it the H1 only or other H1a, b and so having perhaps mutations? Does it come so far from H1?


I'm not sure, and as far as I know the genetic component of diabetes risk is mainly autosomal.

AJL
08-21-2012, 12:47 AM
The other thing is one can assume the Hazda are not overweight, yes? What about the office workers used for the study, are they overweight or do they have a "normal" BMI?
Additionally, I thought that effective weight loss methods varied depending on certain genetic factors which differed from one person to an other. I remember reading about the Hazda people, who've remained this way, in this lifestyle for millenia wouldn't their energy expenditure and calorie intake be optimal for that lifestyle?

Yes, both good points.

Also, re risk for diabetes, this study is interesting (or at least I find it so).

http://www.diabetes.ca/documents/for-professionals/CJD--Sept_2003--Hegele,_R.pdf

utR!
08-21-2012, 02:24 PM
Yes, both good points.

Also, re risk for diabetes, this study is interesting (or at least I find it so).

http://www.diabetes.ca/documents/for-professionals/CJD--Sept_2003--Hegele,_R.pdf

I found it interesting too. I just started to wonder how they had time to walk, merely walk 100 km/day. My longest walk has been 20 km can not remember was it 3 hours. I did not wanted to wait a bus so I started to walk.

The study shows how much still exercise had played a role of keeping sugar level in a healthy level. I think we just do not realise how easily we give up our habits of exercise. I do normally walk many km but it is extremly difficult when I'm tired and stressed. Maybe I'll go walking today when coffee wakes me up.........

tuuli

Ezana
08-26-2012, 04:11 PM
Scarlet, I think you're reading too much into the study. It doesn't show that exercise doesn't help with weight loss, just that metabolism can adapt to different situations and tends to stabilize to a certain level per body mass.

Ezana
08-26-2012, 04:12 PM
The first author of the study, Herman Pontzer, has an article out in the New York Times explaining their findings: http://www.nytimes.com/2012/08/26/opinion/sunday/debunking-the-hunter-gatherer-workout.html




http://graphics8.nytimes.com/images/2012/08/26/sunday-review/26graymatter/26graymatter-articleLarge.jpg

By HERMAN PONTZER
Published: August 24, 2012


DARWIN isn’t required reading for public health officials, but he should be. One reason that heart disease, diabetes and obesity have reached epidemic levels in the developed world is that our modern way of life is radically different from the hunter-gatherer environments in which our bodies evolved. But which modern changes are causing the most harm?

Many in public health believe that a major culprit is our sedentary lifestyle. Faced with relatively few physical demands today, our bodies burn fewer calories than they evolved to consume — and those unspent calories pile up over time as fat. The World Health Organization, in discussing the root causes of obesity, has cited a “decrease in physical activity due to the increasingly sedentary nature of many forms of work, changing modes of transportation and increasing urbanization.”

This is a nice theory. But is it true? To find out, my colleagues and I recently measured daily energy expenditure among the Hadza people of Tanzania, one of the few remaining populations of traditional hunter-gatherers. Would the Hadza, whose basic way of life is so similar to that of our distant ancestors, expend more energy than we do?

Our findings, published last month in the journal PLoS ONE, indicate that they don’t, suggesting that inactivity is not the source of modern obesity.

Previous attempts to quantify daily energy expenditure among hunter-gatherers have relied entirely on estimation. By contrast, our study used a technique that calculates the body’s rate of carbon dioxide production — and hence the calories burned per day — by tracking the depletion of two isotopes (deuterium and oxygen-18) in an individual’s urine over a two-week period.

It was a testament to the Hadza’s graciousness, and their years of friendship with several of my colleagues, that they welcomed us into their camps and participated in the study. As we sat back and observed, the Hadza went about their normal routines.

The Hadza live in simple grass huts in the middle of a dry East African savanna. They have no guns, vehicles, crops or livestock. Each day the women comb miles of hilly terrain, foraging for tubers, berries and other wild plant foods, often while carrying infants, firewood and water. Men set out alone most days to collect honey or hunt for game using handmade bows and poison-tipped arrows, often covering 15 to 20 miles.

We found that despite all this physical activity, the number of calories that the Hadza burned per day was indistinguishable from that of typical adults in Europe and the United States. We ran a number of statistical tests, accounting for body mass, lean body mass, age, sex and fat mass, and still found no difference in daily energy expenditure between the Hadza and their Western counterparts.

How can the Hadza be more active than we are without burning more calories? It’s not that their bodies are more efficient, allowing them to do more with less: separate measurements showed that the Hadza burn just as many calories while walking or resting as Westerners do.

We think that the Hadzas’ bodies have adjusted to the higher activity levels required for hunting and gathering by spending less energy elsewhere. Even for very active people, physical activity accounts for only a small portion of daily energy expenditure; most energy is spent behind the scenes on the myriad unseen tasks that keep our cells humming and our support systems working. If the Hadza’s bodies somehow manage to spend less energy in those areas, they could easily accommodate the elevated energy demands of hunting and gathering. And indeed, studies reporting differences in metabolic-hormone profiles between traditional and Western populations support this idea (though more work is needed).

Our findings add to a growing body of evidence suggesting that energy expenditure is consistent across a broad range of lifestyles and cultures. 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.

All of this means that if we want to end obesity, we need to focus on our diet and reduce the number of calories we eat, particularly the sugars our primate brains have evolved to love. We’re getting fat because we eat too much, not because we’re sedentary. Physical activity is very important for maintaining physical and mental health, but we aren’t going to Jazzercise our way out of the obesity epidemic.

We have a lot more to learn from groups like the Hadza, among whom obesity and heart disease are unheard of and 80-year-old grandmothers are strong and vital. Finding new approaches to public health problems will require further research into other cultures and our evolutionary past.

Herman Pontzer is an assistant professor of anthropology at Hunter College and a co-founder of the Hadza Fund, a nonprofit organization that supports the Hadza population.
A version of this op-ed appeared in print on August 26, 2012, on page SR5 of the New York edition with the headline: Debunking the Hunter-Gatherer Workout.