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Body Composition – Body Fat Percentages

In previous articles I’ve looked at what body composition is along with showing a variety of body composition calculations that can be done.  I also examined different methods of measuring body composition.   Continuing on that topic I want to address a fairly common question that comes up: what is a good body fat percentage (BF%)?

What Is a Good Body Fat Percentage?

As with most topics in the world, and especially in fitness and health, the answer to this question is hugely context dependent.  Are we talking about general health and wellness, athletic performance, competing in one of the physique sports such as bodybuilding, fitness or physique?  The specific goal will determine what body fat percentage might be good, bad or ideal.

General Health and Wellness

When looking at the topic of general health and wellness, it’s generally accepted that both too much and too little body fat can be unhealthy.  As body fat percentage goes up there is an increased risk of insulin resistance or the Metabolic Syndrome with overall risk of many diseases increasing.

I’d note that some of that risk depends on how that body fat is distributed.  In general, women’s lower body (gynoid) body fat patterning is less metabolically unhealthy than men’s central (android) body fat patterning.  This is a large part of why men are at a greater risk for many diseases (i.e. heart attacks) than women.

A very low body fat percentage can be equally unhealthy, even in highly trained athletes.  At least some of this is due to the low calorie intakes required to reach a low BF% but the point stands.   Body fat plays a role in hormonal production, immune system along with having other important functions.   Very low BF% is often associated with disease states, as well.  I’ll come back to this again later in the article.

Although the numbers have likely gone up in recent years, average body fat percentages are usually listed around 12-18% for men and 21-28% for women.  Healthy body fat levels are in the realm of 10-15% or men and 18-25% for women.

Let me mention, semi-tangentially that even if those specific numbers are not attainable by someone, a large amount of research shows that weight/fat losses of even 10% of current body weight improve all health parameters and decrease the risk of disease.  Even if someone can’t reach “healthy” BF% values, they can still improve their health by losing fat.

Finally I’d note that some research suggests that active individuals who carry more fat are healthier than they are inactive.  Some, but not all research, finds that they may be healthier than skinnier/leaner individuals who are inactive although this is highly debated.

BMI and Health

I’d note that some don’t even use body fat percentage itself, preferring to use the Body Mass Index (BMI) as a proxy for health.  For the general public, this is generally an adequate method.  It’s not perfect, of course.  Some people with a high BMI may be perfectly metabolically healthy and some with a normal BMI may be unhealthy.  A low BMI, usually seen in individuals with wasting diseases or some types of eating disorders is usually unhealthy.

BMI can even be used, in the untrained, to roughly estimate body fat percentage.  I’ve used this method in my books for years, having first introduced them in my Rapid Fat Loss Handbook and Guide to Flexible Dieting.

Where BMI becomes useless is when looking at trained individuals.  The problem is that BMI is based on weight and height and doesn’t actually take into account body composition.   A highly trained athlete at 200 lbs and 10% bodyfat and a sedentary individual at 200 lbs and 25% bodyfat have an identical BMI if they are the same height.  But their health risk is clearly very different.

The Physique Sports?

The physique sports such as bodybuilding, fitness, figure, bikini and others are unique among sports in that they are judged solely on appearance.  And at least one criteria of appearance is leanness.

Now, in this sense, judges don’t care what specific body fat percentage the athlete is at.  Rather, there tend to be certain average body fat percentages that correlate with the required appearance.

For this reason, physique athletes don’t really have much if any say in what BF% they have to reach to be competitive.  The ideal/required value will be that required by their sport and nothing more.

In general, for example, male bodybuilders will need to be 3-5% body fat (the lower limit) on competition day.  A female bodybuilder would need to be in the 10-12% range or so.  These represent the lower limits of human BF%.

Very tangentially let me note that natural bodybuilders never maintain that level of BF% year round.   Certainly not if they want to feel healthy, energetic or make gains in muscle mass in the off-season.  Certainly there are those genetic exceptions who stay super lean all the time but they are only exceptions.

The major reason for this is hormonal as maintaining that level of body fat or, more accurately, keeping energy intake that low, causes enormous problems hormonally and physiologically.   Men may become hypogonadal (testosterone below the normal range) and women will lose their menstrual cycle and suffer bone density loss.  I discuss the hormonal effects of this in A Guide to Calorie Partitioning.

It’s not uncommon to see professional bodybuilders maintain that level of leanness year round but they invariably have a variety of drugs to offset the hormonal decrements that occur in naturals. Anabolic steroids, thyroid drugs, Growth Hormone, clenbuterol and others can give them a relatively “normal” hormonal profile despite maintaining single digit BF% year round.

On average, an off-season male bodybuilder might stay in the 12% range in their off-season with a female in the 22-24% or so.  This allows them to eat enough to make gains while being lean enough to diet down when their next contest rolls around.

The body fat requirements for the other physique sports vary somewhat from bodybuilding.  Classic bodybuilding tends to require similar levels of leanness with physique being a tiny bit higher.  Fitness is higher still and women’s bikini competitors may need be no leaner than 16% body fat or so to be competitive.  The requirements for overall muscularity tends to go down as well.

Performance Sports

In contrast to physique sports which are judged on appearance, physique sports are judged on, well, performance.  How fast someone runs, how far they can throw, how much weight they can lift.  Other sports have other criteria but tend to be rather objective.  Did a figure skater do the required jumps and movements in their sport, etc?

Certainly some sports such as figure skating and gymnastics may have an aesthetic component to them, where the overall score, has an appearance component.  But this is not true of most sports that are done.  In this case, any optimal BF% is determined simply by what allows for the best performance.  Outside of the possible vanity of the athlete, appearance is not relevant.

That said, optimal BF% for performance athletes can vary enormously from the most extreme lows to very high indeed.  In general, athletes who need to move their bodies against gravity tends to have the lowest BF%.

This includes runners, jumpers, cyclists who have to climb a lot of hills, etc.   This is due to body fat being nothing more than dead weight which has to be carried.  This isn’t universal.  Combat sports such as rugby or American football involve a lot of running but also involve hard impacts from other players.  Here BF% tends to be higher.

In sports with less of a gravity component, body fat percentage is usually higher. Swimmers tend to carry proportionally more fat than runners or cyclists and even track cyclists who don’t have to climb hills are not as lean as their road cycling counterparts.  I’ll look at more specifics below.

Let me note again that a lower body fat percentage is not always superior for the reasons I mentioned above.    Hormones crater, reproductive function is impaired, bone mineral density may drop increasing the risk of certain types of injuries, etc.  As well, the calorie restriction required to achieve and maintain extremely low levels of body fat impairs the ability to train effectively.  Somewhere between too fat and too lean optimizes performance.

Some Representative Body Fat Percentages

With that said, let’s look at some representative numbers for various athletes, mainly of the endurance type.   Typically, elite male runners clock in around 5- 6% body fat, cyclists around 8-10% and swimmers at 10-12%.  Due to differences in essential fat, women’s BF% are generally higher by anywhere from 5-12%.  So an elite female runner may be 10-12%, a cyclist 15-18% and swimmers 18-20%.

I’d note that the differences in BF% are a big reason for the performance differences between women and men which are, on average, about 10% (it varies by sport from a low of 7% to a high of nearly 25% depending on the sport).

Speaking of swimming, now you know why it’s often said that “Swimmers are fat”.  It’s because they carry slightly more fat than other elite athletes (a whopping 10-12% compared to 6-8%). Obviously they are still leaner than the majority of folks out there.  It’s typically been thought that this was due to the higher BF% helping swimmers float.  I don’t know how true this is in the modern era with the new suits being worn but I’m getting off topic.

When you get into other sports it can become much more variable.  In track and field, discus and shotputters tend to be fairly large and are rarely lean due to the physics involved.  Javelin throwers are very lean due to the running component of their event.  Jumpers are always lean since they have to move up against gravity.

In team sports, things vary by sport and by position.  Soccer players tend to be fairly lean while American football player can range from lean (receiver, running back) to morbidly obese (offensive or defensive lineman).  Basketball players tend to be at a fairly average body fat percentage.

Perhaps the most excessively high BF% is seen in sumo wrestlers, one of the few sports that had made morbid obesity a requirement for success.  There, a body fat percentage of 50% or more is likely to be seen.  Only linemen in American football might come close.

I should mention the strength/power sports.  In Powerlifting and Olympic lifting, it’s common for people to think of the athletes as being fat but this is a myth.  In all but the superheavy weight class (which has no weight limit), the athletes are usually extremely lean.  Since they have to meet a weight class, the leaner they are (up to a point), the more muscle they can carry at any given weight.  In strongman, athletes have certainly become leaner over the years, often sporting full six-packs for the men in the modern era.

But when you’re looking at performance sports, you see an incredible range of optimal body fat percentages depending on the sport.  I’ll only reiterate that every sport tends to have it’s own optimum BF% with levels both above AND below that usually harming performance.

General Appearance

The final category I want to address is that of general appearance.  That is, what is a good body fat percentage to achieve the oft-stated goals of women and men (ie. lean thighs for women or visible abs for men).

Please note that I am not saying that these goals are good or bad in and of themselves (in many cases they can be a negative as they push people down a bad path to try to achieve them).   They tend to be societally driven, engrained in us by various media images of what constitutes physical attractiveness.  I am simply addressing what level of body fat is necessary to achieve them.

While there is some variance depending on how someone carries their body fat, an average male may have to be below 10% body fat to have visible abdominals (i.e. the much coveted 6-pack) and get rid of visible love handles (the fat above the hip bone).  Unless a woman is genetically blessed or carries her body fat in a very even pattern, she might need to achieve a body fat percentage of 15-16% before her thighs lean out significantly.  I’d note that women will usually have visible abs by this point.

This is one of those amusing ironies.  In the middle teen percent body fat, men will have cut legs but a fairly squishy midsection. Even at 12%, most men will have very lean legs but barely visible abs.  In contrast, at 16% a woman will usually have a full six-pack but her legs may still be smooth.  And both will want what the other has.  The man would happily accept some fat on his legs to have visible abs and vice versa.  The grass is always greener folks.

In any case, these are fairly low levels of body fat compared to the average or what is recommended to be generally healthy and getting there can be quite challenging for various reasons.   One is simply that it will take a great deal of dedicated focus on training and diet to achieve them in the first place. Maintaining those levels will tend to require the same amount of focus.

As well, the last bit of fat to lose, abs and low back for men and hips and thighs for women, can be stubborn for various physiological reasons.  All of these are discussed, along with solutions to them, in my book The Stubborn Fat Solution.

I’d also note that some women and men have essentially reversed body fat patterning.  Men may have a more traditionally “female” fat patterning where they carry more fat on their legs and less on their abdominals.  Women suffering from many types of PCOS can also have a more “male” fat patterning with abdominal and vicseral fat.  Women who go through menopause without hormone replacement often see a shift from a lower body to central fat pattern.  As I discuss in The Women’s Book, this is associated with an increased health risk.

Regardless, on average I’d say that achieving the current standard of physical perfection shown in most forms of media will require a male to reach 8-10% body fat and a woman perhaps 15-16% body fat.

A Lower Body Fat Percentage is NOT Better

Before wrapping up, I really want to drive the point home that a lower body fat percentage is not always better.  It’s not better from a health standpoint and it’s rarely better from a performance standpoint.  As usual the physique sports are unique in that an extremely low body fat may be required but this is just a weird exception.

While it’s related less to body fat percentage per se and more to something called energy availability, at some point in the extreme dieting needed to reach very low BF% levels, the system tanks.  Hormones are disrupted and both women and men will see huge drops in reproductive hormones.

Men can become hypogonadal and testosterone can approach near-castrate levels as they reach the lower limits of body fat. Complaints of zero sex drive (and not being able to function sexually even if the drive were there) are common among natural bodybuilders who get extremely lean.

Women may suffer menstrual cycle dysfunction finally culminating in a total loss of the cycle.  This is called amenorrhea and it, along with other, less severe menstrual cycle disorders are discussed in The Women’s Book Vol 1.   While this is not inherently damaging, bone mineral density is eventually lost, increasing the risk of injury.  Depending on the severity of loss, it may never be completely recovered.

This is the tip of the iceberg.  Thyroid, growth hormones, IGF-1, metabolic rate and immune system are all depressed under these conditions.  Cortisol goes up to extremely high levels, especially if a lot of training is being done.  It’s all part of a coordinated set of adaptations that occurs with insufficient long-term calorie intake.

For those truly obsessed with body image, body fat percentages of ~8 for men and  15-16% for women should be safely sustainable year round although it will require nearly fanatical devotion to daily diet and training (or having picked the right parents to start with). As long as the person is at least eating at maintenance while they maintain that body fat percentage.

Good Body Fat Percentages

I want to finish by summarizing the above information, with one added issue. When I talked about the percentage estimates above, I was using numbers obtained from older methods such as calipers, underwater weighing, etc.  I bring this up since may people in the modern era are using DEXA (Dual-Energy X-ray Absorbitometry) to both measure BF% and get a bone density scan.

And I bring that up since DEXA seems to give anywhere from 3-6% higher values than other methods.   Many contest male bodybuilders who would have been measured at 4-5% by older methods have had DEXA show them at up to 9% bodyfat.  In the chart below I’ve listed approximate BF% goals along with the DEXA equivalent in parentheses.

Good Body Fat Percentage for Different Goals

The Guide to Body Composition continues in Body Composition – Measurement Methods

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