# What is the advantage to storing inner thigh fat? **URL:** \ **Category:** Factual Questions\ **Created:** [July 16, 2017, 10:02pm UTC](https://boards.straightdope.com/t/what-is-the-advantage-to-storing-inner-thigh-fat/791437 "2017-07-16T22:02:14Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Contemplation](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@Contemplation](https://boards.straightdope.com/u/Contemplation)\ **Post date:** [July 16, 2017, 10:02pm UTC](https://boards.straightdope.com/t/what-is-the-advantage-to-storing-inner-thigh-fat/791437/1 "2017-07-16T22:02:14Z")
This isn’t related to my previous thread at all, but I just wondered why humans store so much fat in the inner thigh area. Most other animals don’t store a lot of fat here. The thighs of just about every other land animal touch very little compared to humans. Most people in the normal BMI of weight have thighs that touch when they are standing upright with their feet together. Fat in the inner thighs increases friction when walking and running. Some of this friction becomes heat. This means that by having thighs that rub together you are wasting energy and your body is less energy efficient. Humans allegedly evolved out of Africa, so what’s the point of having this extra friction in a tropical environment? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [July 16, 2017, 10:13pm UTC](https://boards.straightdope.com/t/what-is-the-advantage-to-storing-inner-thigh-fat/791437/2 "2017-07-16T22:13:24Z")
_So much fat_? Compared to what? People store fat in many places - abdomen, arms, legs. It doesn’t take too much extra volume before the thighs rub. But, I would suspect that being grossly overweight wasn’t much of an issue to our ancestors in Sub-Saharan Africa. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [July 16, 2017, 11:08pm UTC](https://boards.straightdope.com/t/what-is-the-advantage-to-storing-inner-thigh-fat/791437/3 "2017-07-16T23:08:10Z")
The difference with other animals is, I think, that being primarily bipedal places our legs closer together. Most animals usually have a “thigh gap” … humans who are not professional female models? Not so much so. Even obese animals therefore do not get much thigh friction. ---
**Author:** ![Contemplation](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@Contemplation](https://boards.straightdope.com/u/Contemplation)\ **Post date:** [July 16, 2017, 11:35pm UTC](https://boards.straightdope.com/t/what-is-the-advantage-to-storing-inner-thigh-fat/791437/4 "2017-07-16T23:35:02Z")
Most people actually tend to store more fat on the inner thigh than the outter thigh. The only people whose body doesn’t do this are very attractive women in their reproductive years. Most women don’t store fat that kind of way even when they are young though. The fact that most people have this physical trait probably means it offered some kind of survival benefit to our ancestors. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [July 17, 2017, 1:25am UTC](https://boards.straightdope.com/t/what-is-the-advantage-to-storing-inner-thigh-fat/791437/5 "2017-07-17T01:25:11Z")
> [@Contemplation](#): > > Most people actually tend to store more fat on the inner thigh than the outter thigh. The only people whose body doesn’t do this are very attractive women in their reproductive years. Most women don’t store fat that kind of way even when they are young though. > > The fact that most people have this physical trait … Sorry but - cite please. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [July 17, 2017, 1:37am UTC](https://boards.straightdope.com/t/what-is-the-advantage-to-storing-inner-thigh-fat/791437/6 "2017-07-17T01:37:08Z")
In addition to the “2 legs good 4 legs bad” point already made, consider that the OP is talking about people standing with their feet together, touching each other on their inner edge. A typical quadruped will not stand with the rear feet touching; they adopt a wider stance. A typical quadruped does not have feet nearly as wide proportionally as a human. Look at a hoof or a dog’s paw. Much narrower. If an adult human stands with their legs going straight down from the hip joints, as does a typical quadruped, there’ll be 6-10" between the inner edges of the feet. At which point unless that person is obese, their inner thighs are unlikely to touch. ---
**Author:** ![Aspidistra](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aspidistra/32/3894_2.png) [@Aspidistra](https://boards.straightdope.com/u/Aspidistra)\ **Post date:** [July 17, 2017, 2:02am UTC](https://boards.straightdope.com/t/what-is-the-advantage-to-storing-inner-thigh-fat/791437/7 "2017-07-17T02:02:10Z")
From an engineering point of view, the best place to store excess fat seems to be “as close to the hip joint as possible.” Having fat too far down the legs means a lot of extra mechanical work when walking due to the effects of leverage (think how much harder it would be to walk with kilo weights strapped to your feet as opposed to your hips) - having fat too far up makes you top-heavy and prone to tip over. So the sweet spot is definitely between the tummy and upper thigh. Having come to that conclusion, there’s then only so many places you can put the fat, and a lot of modern folks have a fair bit of fat to store _somewhere_. So - do people have more fat on the inner thigh than the outer thigh, butt or tummy? I don’t know that that’s proven, actually. ---
**Author:** ![mmmiiikkkeee](https://avatars.discourse-cdn.com/v4/letter/m/edb3f5/32.png) [@mmmiiikkkeee](https://boards.straightdope.com/u/mmmiiikkkeee)\ **Post date:** [July 17, 2017, 5:31am UTC](https://boards.straightdope.com/t/what-is-the-advantage-to-storing-inner-thigh-fat/791437/8 "2017-07-17T05:31:12Z")
> [@Contemplation](#): > > This means that by having thighs that rub together you are wasting energy and your body is less energy efficient. The amount of heat from friction of rubbing body parts is nothing compared to the amount of body heat continually being radiated away. Also, a person with enough body fat to have body parts rubbing against each other when they move doesn’t need to conserve energy as they have stored too much already. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [July 17, 2017, 11:57pm UTC](https://boards.straightdope.com/t/what-is-the-advantage-to-storing-inner-thigh-fat/791437/9 "2017-07-17T23:57:59Z")
> [@Aspidistra](#): > > From an engineering point of view, the best place to store excess fat seems to be “as close to the hip joint as possible.” Having fat too far down the legs means a lot of extra mechanical work when walking due to the effects of leverage (think how much harder it would be to walk with kilo weights strapped to your feet as opposed to your hips) - having fat too far up makes you top-heavy and prone to tip over. It’s also less prone to cause health problems I understand. Both because thigh fat is more stable (which is also why it’s harder to lose), and because the thighs are made of muscle and bone; not the more delicate internal organs of the belly. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [July 18, 2017, 12:21am UTC](https://boards.straightdope.com/t/what-is-the-advantage-to-storing-inner-thigh-fat/791437/10 "2017-07-18T00:21:45Z")
Not to endorse the OP’s contention that the inner-thigh is a key target for fat, but I will note that the major arteries go down the inside of the thigh. Fat is a pretty good insulator, so by putting it over top of the major veins, the amount of energy that needs to be spent to keep the body warm would be decreased. There could also be a benefit of providing extra prevention from cuts nicking something vital. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [July 18, 2017, 3:30am UTC](https://boards.straightdope.com/t/what-is-the-advantage-to-storing-inner-thigh-fat/791437/11 "2017-07-18T03:30:34Z")
One would suspect that **Aspidistra** has the best answer. Get the mass distribution to best effect. Evolution is not going to select against inner thigh fat unless there is loss of fitness as a result, and getting the fat near the hips is probably enough of a significant increase in fitness to counter trivial issues. Of course there is a sex linked distribution here - as women don’t lay down the amounts of inner abdominal fat that men do. Doing so is a big strike against reproductive fitness, even though it is probably the best place to actually place the extra mass.