What is the body fat % range that is most healthy?
It’s different for men and women.
I’d appreciate an authoritive site, especially from a uni or government agency.
I really want to fight the idea that skinnier is always better.
Depends on how you achieve it. A man at 3% who starves himself to get there will have far more problems than a bodybuilder or endurance athlete who gets there through exercise and a sensible diet.
This page has some charts detailing normal ranges by age, gender and sport.
/nitpick
Even any bodybuilder getting his bodyfat percentage down to 2-3% is going to engage in some pretty extreme dietary manipulations to achieve it. “Sensible” might not be the most accurate descriptor of such practices. 
/nitpick
I was thinking of Clarence Bass. I haven’t heard that he’s had any trouble related to his BF%.
His diet seems to be well thought out. It was his fanatical devotion to achieving a number I found a little off-putting.
It’s probably genetic that he can reach that level while others in the sport don’t.
Also, Frank Shorter (Olympic marathon Gold 1972, Silver '76) was said to be around 2-3%
Thank you for your answers
Certain rare, genetically gifted bodybuilders may be able to obtain such low body fat percentages without grueling diet restrictions but they are the exception, not the rule. And I never commented on the ease with which endurance runners can achieve such low bf %s. If retaining muscle mass is not the top concern, then it gets much “easier” to drop to ridiculously low bodyfat. I say “easier” because the shit still aint easy (nor is it the goal of runners, rather a side effect of the tremendous training load).
If you were the captain of a British slave ship, the fatter the captives were, the better. That meant you could feed them less on the months long journey from africa and have less slaves die on the way.
Wouldn’t retaining muscle mass inevitably decrease your body fat percentage? Muscle is more dense than fat so it would make sense that having more of it as opposed to fat would decrease your body fat percentage.
It’s a really interesting question, precisely for the reasons already stated. One way to get at it some is to look at the impact of percent body fat as a risk marker after others like BMI and waist-to-hip ratio (WHR) are controlled for, which is what they did here. Over 15,000 middle-aged and older adults prospectively followed for about a decade and as it turned out the slight edge to the worst hazard ratio (HR) was in the lowest quartile for percent body fat. WHR did the best as a stand-alone. (Which it does inconsistently in studies, sometimes outperforming BMI and sometimes not.)
How to explain that??
The best I can come up with is two-fold. First is that the key issue is where the fat is, the distribution, more than how much there is. Low percent body fat but stored in a belly paunch, in “visceral fat”, exclusively, is not good. In fact some subcutaneous fatmay even be a bit protective! WHR captures that and only the very lowest percentiles of body fat will drive subcutaneous fat way down (hence the fact that washboard abs do not show until one is at an absurdly low percent BF). Second the lowest percentiles may have reverse causation going on - they may be exceptionally thin because they have (already diagnosed or not) some ill health in place.
What percents body fat are in that lowest quartile? This article (tables 3 and 4) tell us that for men 20 to 39 years old only 3.8% are under 15% BF and more than half are over 25% BF (“obese” according to the link provided by running coach*). For men over 40 years old the under 15%BF goes down to a fraction of a percent and 75% are 25%BF or higher. For women 20 to 39 the lowest listed under 25%BF is 4.2%, 11% are in the 25 to < 30 and 24% in the 35 to <40 - the rest higher; by 40 to 59 years old the norms are 19% under 35 in total and more than half over 40%BF.
So less body fat overall is not more protective per se. It may be the best is to have the least possible visceral fat while avoiding losing so much subcutaneous fat that you get washboard abs. Yes, exercise, especially with some occasional intensity, is pretty highly associated with preferential loss and avoidance of visceral fat.
*Not sure where that link gets their numbers for what is “average” but they are way off from what the large database in the 2009 article I cited comes up with. Maybe they are using numbers from the 60s or something?
Hey! I’m retired okay, I’ve left my slave trafficking days long in the past.
You can see from the risk of death vs BMI chart here that you have to get pretty far into the obese category before your risk of death is as high as people on the low end of “normal”. I don’t know how that translates to body fat, but I think the “lower body fat is healthier” idea has been put to rest.
There is nothing healthy about a 3% body fat percentage. It takes muscle mass to stay healthy into your old age, and to gain muscle naturally you must necessarily gain fat. Anyone at 3% is either anorexic, on steroids, or both.
See here for an essay exploring the misunderstanding that thinner is always healthier.
That’s a bit of an overstatement when the very curve you linked to shows mortality risk increasing monotonically for BMI values over 24. A huge percentage of Americans are in that range.
Also I suspect that the curve you linked to isn’t corrected for smoking status, which has been linked to lower BMI.
Right, but we’ve got posters in here talking about 3% body fat. Less fat is better, to a point. Then it becomes very bad. So “as little fat as humanly possible” is not the correct answer. It’s much higher than that.
Notice how the mortality decreases monotonically until 24, as well. My point isn’t that obesity is healthy, it’s that low body weight is as unhealthy as being obese, unless you are an extremely obese outlier on the BMI charts. Eyeballing the chart, it looks to me like a “normal” BMI of 19 is just as unhealthy as an “obese” BMI of 34. Though you’re right, smoking is probably not controlled for in this graph.
A lot of people seem to think mortality vs. BMI looks like a hockey stick, where more is always worse. But it’s not, it’s a skewed ‘U’, with a sweet spot somewhere in the middle. And it looks to me like that sweet spot is on the high end of “normal”, with a little bit overweight being just as healthy as the middle of the “normal” range.
BMI and body fat percent do not 100% correlate, obviously. Again though the data shows that lower body fat for a given BMI and/or WHR does not mean less mortality risk, if anything the lowest quartiles on %BF for given BMIs and WHR did slightly worse. Counterintuitive that but consistent with the stand alone BMI data that the thinnest do not do so well.
Interestingly of those Americans with BMI under 25
Now as that article notes, “*t’s still unknown, however, how much body fat is healthy” but such does suggest that those in the “sweet spot” for BMI correlations with health outcomes (as noted generally in the high normal range) are not very low in percent body fat.
Frank Shorter is an interesting anecdote but one suspects that he did not stay at that absurdly low %BF for much time other than peaking for competition.