Thursday, December 2, 2010

How lean should one be?

Loss of muscle mass is associated with aging. It is also associated with the metabolic syndrome, together with excessive body fat gain. It is safe to assume that having low muscle and high fat mass, at the same time, is undesirable.

The extreme opposite of that, achievable though natural means, would be to have as much muscle as possible and as low body fat as possible. People who achieve that extreme often look a bit like “buff skeletons”.

This post assumes that increasing muscle mass through strength training and proper nutrition is healthy. It looks into body fat levels, specifically how low body fat would have to be for health to be maximized.

I am happy to acknowledge that quite often I am working on other things and then become interested in a topic that is brought up by Richard Nikoley, and discussed by his readers (I am one of them). This post is a good example of that.

Obesity and the diseases of civilization

Obesity is strongly associated with the diseases of civilization, of which the prototypical example is perhaps type 2 diabetes. So much so that sometimes the impression one gets is that without first becoming obese, one cannot develop any of the diseases of civilization.

But this is not really true. For example, diabetes type 1 is also one of the diseases of civilization, and it often strikes thin people. Diabetes type 1 results from the destruction of the beta cells in the pancreas by a person’s own immune system. The beta cells in the pancreas produce insulin, which regulates blood glucose levels.

Still, obesity is undeniably a major risk factor for the diseases of civilization. It seems reasonable to want to move away from it. But how much? How lean should one be to be as healthy as possible? Given the ubiquity of U-curve relationships among health variables, there should be a limit below which health starts deteriorating.

Is the level of body fat of the gentleman on the photo below (from: low enough? His name is Fedor; more on him below. I tend to admire people who excel in narrow fields, be they intellectual or sport-related, even if I do not do anything remotely similar in my spare time. I admire Fedor.

Let us look at some research and anecdotal evidence to see if we can answer the question above.

The buff skeleton look is often perceived as somewhat unattractive

Being in the minority is not being wrong, but should make one think. Like Richard Nikoley’s, my own perception of the physique of men and women is that, the leaner they are, the better; as long as they also have a reasonable amount of muscle. That is, in my mind, the look of a stage-ready competitive natural bodybuilder is close to the healthiest look possible.

The majority’s opinion, however, seems different, at least anecdotally. The majority of women that I hear or read voicing their opinions on this matter seem to find the “buff skeleton” look somewhat unattractive, compared with a more average fit or athletic look. The same seems to be true for perceptions of males about females.

A little side note. From an evolutionary perspective, perceptions of ancestral women about men must have been much more important than perceptions of ancestral men about women. The reason is that the ancestral women were the ones applying sexual selection pressures in our ancestral past.

For the sake of discussion, let us define the buff skeleton look as one of a reasonably muscular person with a very low body fat percentage; pretty much only essential fat. That would be 10-13 percent for women, and 5-8 percent for men.

The average fit look would be 21-24 percent for women, and 14-17 percent for men. Somewhere in between, would be what we could call the athletic look, namely 14-20 percent for women, and 6-13 percent for men. These levels are exactly the ones posted on this Wikipedia article on body fat percentages, at the time of writing.

From an evolutionary perspective, attractiveness to members of the opposite sex should be correlated with health. Unless we are talking about a costly trait used in sexual selection by our ancestors; something analogous to the male peacock’s train.

But costly traits are usually ornamental, and are often perceived as attractive even in exaggerated forms. What prevents male peacock trains from becoming the size of a mountain is that they also impair survival. Otherwise they would keep growing. The peahens find them sexy.

Being ripped is not always associated with better athletic performance

Then there is the argument that if you carried some extra fat around the waist, then you would not be able to fight, hunt etc. as effectively as you could if you were living 500,000 years ago. Evolution does not “like” that, so it is an unnatural and maladaptive state achieved by modern humans.

Well, certainly the sport of mixed martial arts (MMA) is not the best point of comparison for Paleolithic life, but it is not such a bad model either. Look at this photo of Fedor Emelianenko (on the left, clearly not so lean) next to Andrei Arlovski (fairly lean). Fedor is also the one on the photo at the beginning of this post.

Fedor weighed about 220 lbs at 6’; Arlovski 250 lbs at 6’4’’. In fact, Arlovski is one of the leanest and most muscular MMA heavyweights, and also one of the most highly ranked. Now look at Fedor in action (see this YouTube video), including what happened when Fedor fought Arlovski, at around the 4:28 mark. Fedor won by knockout.

Both Fedor and Arlovski are heavyweights; which means that they do not have to “make weight”. That is, they do not have to lose weight to abide by the regulations of their weight category. Since both are professional MMA fighters, among the very best in the world, the weight at which they compete is generally the weight that is associated with their best performance.

Fedor was practically unbeaten until recently, even though he faced a very high level of competition. Before Fedor there was another professional fighter that many thought was from Russia, and who ruled the MMA heavyweight scene for a while. His name is Igor Vovchanchyn, and he is from the Ukraine. At 5’8’’ and 230 lbs in his prime, he was a bit chubby. This YouTube video shows him in action; and it is brutal.

A BMI of about 25 seems to be the healthiest for long-term survival

Then we have this post by Stargazey, a blogger who likes science. Toward the end the post she discusses a study suggesting that a body mass index (BMI) of about 25 seems to be the healthiest for long-term survival. That BMI is between normal weight and overweight. The study suggests that both being underweight or obese is unhealthy, in terms of long-term survival.

The BMI is calculated as an individual’s body weight divided by the square of the individual’s height. A limitation of its use here is that the BMI is a more reliable proxy for body fat percentage for women than for men, and can be particularly misleading when applied to muscular men.

The traditional Okinawans are not super lean

The traditional Okinawans (here is a good YouTube video) are the longest living people in the world. Yet, they are not super lean, not even close. They are not obese either. The traditional Okinawans are those who kept to their traditional diet and lifestyle, which seems to be less and less common these days.

There are better videos on the web that could be used to illustrate this point. Some even showing shirtless traditional karate instructors and students from Okinawa, which I had seen before but could not find again. Nearly all of those karate instructors and students were a bit chubby, but not obese. By the way, karate was invented in Okinawa.

The fact that the traditional Okinawans are not ripped does not mean that the level of fat that is healthy for them is also healthy for someone with a different genetic makeup. It is important to remember that the traditional Okinawans share a common ancestry.

What does this all mean?

Some speculation below, but before that let me tell this: as counterintuitive as it may sound, excessive abdominal fat may be associated with higher insulin sensitivity in some cases. This post discusses a study in which the members of a treatment group were more insulin sensitive than the members of a control group, even though the former were much fatter; particularly in terms of abdominal fat.

It is possible that the buff skeleton look is often perceived as somewhat unattractive because of cultural reasons, and that it is associated with the healthiest state for humans. However, it seems a bit unlikely that this applies as a general rule to everybody.

Another possibility, which appears to be more reasonable, is that the buff skeleton look is healthy for some, and not for others. After all, body fat percentage, like fat distribution, seems to be strongly influenced by our genes. We can adapt in ways that go against genetic pressures, but that may be costly in some cases.

There is a great deal of genetic variation in the human species, and much of it may be due to relatively recent evolutionary pressures.

Life is not that simple!


Buss, D.M. (1995). The evolution of desire: Strategies of human mating. New York, NY: Basic Books.

Cartwright, J. (2000). Evolution and human behavior: Darwinian perspectives on human nature. Cambridge, MA: The MIT Press.

Miller, G.F. (2000). The mating mind: How sexual choice shaped the evolution of human nature. New York, NY: Doubleday.

Zahavi, A. & Zahavi, A. (1997). The Handicap Principle: A missing piece of Darwin’s puzzle. Oxford, England: Oxford University Press.


The Ninjew said...


I like this post, but you've got it all wrong. Fedor was simply the better fighter. Look at the Couture/Sylvia fight. Sylvia had everything on Couture. Couture was ripped, Sylvia has always been a little pudgy, and Couture kicked Sylvia's ass, notwithstanding a height/reach/weight disadvantage. I think you are stretching using Fedor as an example.

For that matter, look at Roy "Big Country" Nelson, who is obese, yet has great cardio and can go the distance as a fighter. I think he's good because he's got great power, killer BJJ technique, in spite of his fat.

Ellen said...

Wow. That was an awesome youtube Ned. Thanks as always. Your perspective is always refreshing and interesting.

Asclepius said...

It is tricky comparing MMA/UFC participants because there is a significant amount of skill involved.

Check out the first fight between Brock Lesner vs Frank Mir. Lesner was all over Mir, but then through a degree of naivity, ended up tapping out to an ankle lock.

It'd be interesting to see the impact to Fedor's ability if he lost some fat. I mean even at 10% BF he'd EASILY have enough fat left to see him though a fight. And, carrying less weight, may improve his agility and speed.

In fact thinking of elite athletes across a range of sports (Usain Bolt, Michael Phelps, Lance Armstrong) plenty of them are very lean and compete over a massive range of distances.

The point being that even at 10% BF you still have a LOT of energy at your disposal - and you are carrying less of a 'redundant burden'. No point carrying oversized fuel tanks!

Having said all that, very low BF (<8%) looks grim to me. Best to eat 'right', partake in some vigourous, intense and occasional whole-body exercise, and let your body determine its own BF level!

Nice post.

Michael Barker said...

Ned, as usual, you've been reading my mail.

I'm standing in front of the mirror looking at my lean body and I just don't see it as healthy.

Maybe being Black and seeing that the healthiest Black people tend to be toward the heavier side has something to do with it. (This is especially the case with Black women.)

Research tends to bear this out. The BMI health curve shifts to the right in Black people. A BMI of 25-30 seems to be the most protective.

The fighters are a whole other matter all together. A low center of gravity, excellent balance, the ability to react quickly despite pain and a good skill set is an incredible advantage.

I knew some good wrestlers. One even won an Olympic metal. When asked what was most important, they all said "agility". The ability to counteract your opponents moves by subtle shifts of the body is everything.

Scott W said...

Those who are focusing on the MMA aspect are missing the point.

This is a great post and this topic needs to be out in the open more in all health communities, including paleo. It is so easy for us to be influenced by a genetically "elite" person and assume that we can look similar to them. It would be ideal if a DNA test could be done that would predict where on the bell curve you can expect to "settle" when you have all aspects of your health plan dialed in. It would certainly help with self-acceptance.

A person could do this to some extent by carefully considering his closest genetic matches (parents, siblings). Still, with the force of retouched photos and carefully-selected testimonials, it is very easy to believe that you are just not working hard enough to achieve the results you should be capable of when it comes to leanness.

I have found that there seems to be a BF% that my body can fairly easily stay close to if I'm eating correctly and exercising, etc. The total amount of fat rises and falls in proportion to the amount of muscle I have built. I have tried for years to move below that range and have never been successful. It is possible for me to make a slight downward shift for a few weeks or a month or so, but then "something" always happens to bring me back up...I start to feel cold all the time, I get sick and lose my will to diet, etc.

If I had a full-time personal trainer to watch over and motivate me and a personal chef, etc. maybe I could make it through the rough patches and keep on pushing...but I kind of doubt it.

It comes to self-acceptance of what is possible to maintain on a normal, healthy diet and exercise plan (whatever that is…).

I keep trying, but I’m much closer to believing that In the end I’ll take healthy longevity over 6-pack abs. longevity is the best reward...if you are still climbing trees at 90 like that woman in Okinawa, no one cares a bit what you look like...they all just want to be like you when they "grow up."

Scott W

Geoff said...

"From an evolutionary perspective, perceptions of ancestral women about men must have been much more important than perceptions of ancestral men about women. The reason is that the ancestral women were the ones applying sexual selection pressures in our ancestral past."

This presumes that visual attractiveness is equally important to women as it is to men, which is not a great assumption to make. It can be shown a hundred different ways that physical/visual characteristics are far less important to women than they are to men. Women place more value on personality traits, particularly confidence, charisma and leadership.

Syler W. said...

If one were looking to determine the optimum body composition for one's good health, what objective variables do you think would serve as good benchmarks? Obviously, subjective wellbeing and energy levels play a role, as does frequency of illness, and various benchmarks of sport performance, but what about bloodwork numbers etc.? Curious to know your thoughts.

Anne said...

Hi Ned,

Could you post a photo of someone with the 'buff skeleton look' because I don't know what that would look like.

I thought Fedor looked fat in that photo ! And when I saw the other one with him and Arlovski his fatness was even more apparent !

Abe said...

@Geoff - I think sometimes there is more than just "standard" phyical appearance when it comes to attractiveness. I remember hearing some time ago about a study that was done where women were asked to rate the attractiveness of men. They went through a series of pictures, which included men in their "natural" state, and some men whose pictures had been created by mirroring half of their face, thereby giving them a perfectly symmetrical face. The women consistenly rated the symmetrical faces as more attractive, and the reason given by the authors was that symmetry is a sign of high quality DNA, which the women were physiologically inclined towards, as if in anticipation of finding a high-quality father for their offspring. I believe there is a lot to attraction that is not just about how "pretty" someone is, but about an in-born physiological response to signs of good DNA. That is WHY we find attractive people actractive, after all.

. said...

Body-mass index and cause-specific mortality in 900 000 adults: collaborative analyses of 57 prospective studies. -

Ned Kock said...

Hi Ninjew, thanks. I do agree with most of what you said, but bear in mind that the cases I mentioned in the post are aimed at falsifying a hypothesis.

Ned Kock said...

Thanks Ellen.

Ned Kock said...

Hi Asclepius.

I’ve seen both fights between Mir and Lesnar. As you probably know, the second was won by Lesnar, decisively. I like Mir both as a fighter and commentator.

Both fat and sugar are used as energy sources by MMA fighters. Of the two, the bottleneck is definitely sugar, from liver and muscle glycogen. Even very lean MMA fighters will exhaust their glycogen reserves well before they run out of body fat.

Ned Kock said...

Hi Michael, thanks for that link. Very interesting.

Ned Kock said...

Hi Scott. Indeed, it almost looks like this was a post about MMA.

Ned Kock said...

Hi Geoff. The point you make is correct, and does introduce a confounder into the picture. Women may not find the super lean and muscular look particularly attractive because it may indirectly suggest lack of self-confidence.

Ned Kock said...

Hi Syler W. Assuming everything is within normal ranges, I would say that HDL cholesterol and triglycerides are good numbers to look at. Total cholesterol is practically useless.

Ned Kock said...

Hi Anne. I suspect someone who fits the buff skeleton definition will comment here soon; an angry comment, which I will not delete. The thumbnail picture will probably be a shirtless photo in a forced bodybuilder pose, with the person trying to look bigger and more intimidating than when not posing.

Ned Kock said...

Abe, very nice comment. The following is a post you might like.

Pretty faces are average faces: Genetic diversity and health

Ned Kock said...

Hi Ricardo, thanks for the link. Interesting quote from the study: “Below the range 22.5-25 kg/m(2), BMI was associated inversely with overall mortality, mainly because of strong inverse associations with respiratory disease and lung cancer.”

However, if you look at Figure 5, you’ll see that there is an inverse association below a certain BMI with each and all causes of mortality, including “vascular” and “other specified cancer”.

Brandon Thomson said...

Hard to make conclusions about what weight a healthy person should strive for from epidemiological data.

The CRON community always points out that some diseases (like cancer) cause people to lose weight and some (like diabetes) cause people to gain weight. Smoking also causes people to lose weight.

Cause of death is not necessarily reliable either. For example, someone may get cancer (undiagnosed over their lifetime) which causes them to lose weight and weakens their immune system and then they end up dying of pneumonia which would show up as lower weight associated with risk of death from pneumonia in these studies.

Lots of tricky cause-effect relationships.

3D Face Analysis said...

Would muscularity be a fitness indicator of how much food you can obtain?

If you eat more food, then your muscles will grow bigger. However, if you're starving, then your muscle will shrink. Therefore, muscle may be a fitness indicator of how good you can hunt and gather food.

Muscle may also be a costly fitness indicator in terms of energy availability. Large amounts of muscle in your body will increase your energy expenditure due to the energy maintaining your muscles and the energy moving your increased weight in muscles. Therefore, someone who can obtain lots of energy of food should maintain large amounts of muscle with no problem. However, someone who isn't good at obtaining food won't maintain large amounts of muscle.

I think for men, low body fat levels for may also be a costly fitness indicator. It may indicate that they don't need to store much fat because they can easily get food if they need it.

I think confidence is also a costly fitness indicator. Women are attracted to confident men, but only the strong and powerful can get away with being confident. If you are weak or powerless, for example, then being confident may be dangerous because it may make you vulnerable for stronger and more powerful men. So only the strong and powerful men can get away for being confident, so confidence may also be a costly fitness indicator.

js290 said...

The "weak" don't need confidence, per se. They just need some malandragem. ;-)

Ned Kock said...

Very good points Brandon. It is always difficult to infer causality from cross-sectional studies (i.e., studies where data is collected at one point in time for each unit of analysis). And epidemiological studies are usually cross-sectional.

Ned Kock said...

Hi Organism.

Theorizing about costly traits has to be done carefully; otherwise one may be tempted to believe that everything is a costly trait.

That has been a criticism of Amotz Zahavi’s work; which was made by several notable evolutionary biologists, including John Maynard Smith.

When I theorize about costly traits, I like to build on mathematical biology. If you are interested, see this article:

Kock, N. (2009), The Evolution of Costly Traits through Selection and the Importance of Oral Speech in E-Collaboration, Electronic Markets, V.19, No.4, pp. 221-232.

Ned Kock said...

In case link above gets cut off by blogger, the article is also available by going to the site below and then to the selected pubs. section.

Ned Kock said...

Hi js290. Definitely “malandragem” helps the weak. Some would argue that the ancient Greek were quite fond of “malandros”, in their own way. Odysseus (aka Ulysses) was not really weak, but still was no match for the hideous and one-eyed Polyphemus.

Asclepius said...

Hi Ned,
Agreed that 'the bottleneck is definitely sugar...' - I was just trying to make the case against carrying lots of subcutaneous BF!

Glenn said...

Interesting post, as always. I don't know why someone would be angry about the "buffed skeleton" line; I'm not (althought I don't quite qualify for that description). You mentioned a top bodybuilder in contest shape. This is my training partner, one of the best natural bodybuilders in the world:

Glenn said...

Sorry, the link got cut off:
More at:

Ned Kock said...

Hey Glenn.

Maybe I was wrong about getting angry comments.

On second thought, the main message of the post is that there is a great deal of variation among humans, and that not everybody would be healthy being extremely lean; perhaps only a few, those near the tail ends of the bell curve.

I was going to ask you a couple of questions about Doug, but the answers are already up there on his site. One of several interesting statements:

“I feel that I am the strongest and that I create a very anabolic environment when I am closer to 20-30 lbs over my contest weight.”

To get to Doug’s point one has to put in A LOT of effort, practically live for the sport. And it looks like he does. I admire that, because I myself spend a lot of effort trying to be one of the best in the world in a few narrow scholarly fields (e.g., variance-based structural equation modeling, evolutionary biology as it applies to the study of human-technology interaction).

Doug does not look fit the stereotype that many people have of champion bodybuilders; some aspects of which are certainly unfair. I saw the Documentary on Team Miller video. Doug is clearly very smart, entrepreneurial, and appears to be a great guy.

You’ve been keeping great company!

Anonymous said...

i think you make a very good point with this post. and i absolutely agree with having a body that is healthy is not ALWAYS going to looks like 'you think' it should look. a goal is one thing, but maintaining something outside of your inate ability causes way more health problems than you can imagine. im pretty much living proof of that. and both overweight and underweight come with lost of questions and long term problems.

i doubt ill ever have full trust in my body again, or that it will fully trust me. i doubt i will ever have the 'lean' physique i had as a cheerleader because i wound up underweight with anorexia. it took a toll on my body for the rest of my life, from sleep to bone health to glucose tolerance. it is somewhat reversible but it isnt a 100% cure for me to 'just gain' weight.

i cant workout like i once enjoyed doing. i lift heavy stuff once a week and i know because of the feeling i get on the 6 days off that it strengthens my bones. but still, weather flucuations make walking a chore sometimes. all this because i wanted to be 'small' and lean.

i think brain chemistry has a lot to dow ith weight. how you are 'wired' is going to determine how your body signals its hormones, uptakes aminos, uses and stores food etc. my brain is very much so not 'wired' correctly and it takes a toll on my body health. i think i will always be mentally more capable of fighting the misfiring up there when i am at a higher BMI/BF% than i would visually like, but whatever i FEEL healthier there

David Isaak said...


Interesting post.

But your post of May 15, which shows the photo of the three native Australians was also interesting. Those guys looked pretty healthy to me--and all three of them are showing six-pack abs. I don't know what their body fat percentage is, of course, but people don't generally show six-packs until they are well under 10%...

I feel far better--and things like blood pressure etc are also better--at 14% then at 18%; and the same trend holds true at 12%. I've never gotten below 12%, so I can't tell you where the inversion point in the U-curve is for me, but lower has been better so far.

Ned Kock said...

Hi Mal. Thanks so much for sharing your personal experience. I agree with you regarding the wiring of the brain, and I think that it can be re-wired. It helps to eliminate stressors, and learn how to deal with the ones that can’t be eliminated.

Ned Kock said...

Hi David. Indeed, those three Australian aboriginals look very healthy. The oldest seems to be in his 70s. Maybe that level of body fat is optimal for them; or maybe the oldest is in his 50s and looks like he is in his 70s. Trying to get to the truth always unveils some complications.

Anne said...

Just looked at the photo of the Australian aboriginals - they look very lean, no fat at all and nice muscle, not 'artificial' like some body builders (now I'll get angry comments !), and they 'look' very healthy to me. Of course it's all subjective !

Ned Kock said...

Hi Anne. I guess we are on the safe zone regarding angry comments already. They usually come on the first 2-3 days after the post comes out.

Ned Kock said...

In case anyone would like to know what body fat percentage (BFP) corresponds to the lowest mortality BMI mentioned on the post, here is what I think. If we consider a person who does strength training recreationally, and who is likely fit but not to the level of a competitive athlete, the BFP would be 21-24 percent for women, and 14-17 percent for men. If the person has a bit more muscle, then that BFP will be 14-20 percent for women, and 6-13 percent for men.

David Isaak said...

Those numbers strike me as quite reasonable.

But I just have trouble with population studies of BMI. I think it's a classic case of the drunk looking for his keys under the streetlight because it's the only place he can see. BMI is easy to measure, and often gets measured, and therefore it gets used. But there are so many possible confounding factors.

Or, as Bonzo Dog Band put it in one of their songs many years ago:

"To cut down my weight,
off comes my left leg--
And I pass the swimming-costume test!*"

Ned Kock said...

Indeed David. In fact, it is possible that the left side of the U curve is not causal in the way we are assuming: BMI => health. That is, it is possible that the left side reflects health deterioration causing BMI to go down, as Brandon pointed out. Still, the combined set of data summarized in the post goes some way toward falsifying the idea that very lean = very healthy.

Gym Equipments in Bangalore said...

Nice post. thanks. I do agree with most of what you said, but bear in mind that the cases I mentioned in the post are aimed at falsifying a hypothesis.thanks for sharing here..

viagra online said...

You are right: absence of fat can be dangerous too, even in tropical zones.

Unknown said...

Two years late, but here is the angry comment ;-)
The phrase "buff skeleton" is not only pejorative, it is an oxymoron. By definition, buff means having a large and evenly distributed muscle mass. It covers the skeleton as effectively as fat, rendering the skeleton difficult to discern.
A skeletal appearance requires a low BMI, a shortage of both fat and muscle.
Let me suggest that use of the term "buff skeleton" is a reflection of envy on the part of the speaker. This confirms the idea that a high BMI with low body fat % is indeed a trait conferring a reproductive advantage. It results in the discomfort of those observers lacking the trait, for a good reason explained by evolutionary psychology.