Body Fat % way more than BMI...???

I am using the body fat calculator developed by the US Navy and my BF index is at 32%...but for me, I don't think that makes any sense. Based on my body weight and height, my BMI is roughly 20, so how could be BF be so high?? Here are the stats I used: waistline 29", hips 36", neck 12", wrist 6", forearm 10.5", I weigh 128 pounds and my height is a little under 5'8". I hold all of my weight around my hips, so that could be a factor...I have virtually no body fat in my legs or arms. Do I need to be concerned? Is this an accurate body fat measurement? I also have a scale at home that measures body fat by a using low electrical current that says I am at 21% BF, but I'm not sure how accurate that is.    

My stats are very different from yours, but I too have found that this calculator doesn't seem to work for me.  When I last used it, it had me at ~28% BF, but I knew I was much more than that.  Perhaps others have different experiences; I'd be interested in learning, if I was doing something wrong!

BMI is calculated by height and weight...period. It is a very generic (and not very accurate) indicator of someone's overall body size (and it's relative health). For instance...a female body builder at 5'2" could weigh 140 lbs...and be 12% body fat....but their BMI would be at a 29 (which is considered obese). And someone very small in size, could have zero muscle tone and their weight could be largely body fat...but their BMI could show them at a 15 or 16 (which is borderline "underweight").

As you can see...body fat and BMI have NOTHING to do with the other and body fat is a much better indicator of health (than the BMI). If you want an accurate body fat measurement, go to a personal trainer (who will use callipers to measure fat on various parts of the body and then do a calculation for total body fat). This number may help you to see if your scale or the calculator you used is more accurate.

Good luck on your journey towards health!

i don't have any knowledge about the specific navy bf calculator you're talking about.  but your tape measure numbers are pretty small, so i think your body fat's definitely way less than 32%.  i'm 5'7 and my number are higher than your hip/waist numbers, and i'm much much less than 32% body fat.  what's that forearm measurement about?  are you sure you did that right?  anyway, although everyone is different, that percentage doesn't sound accurate at all.  you sound lean (from the numbers).

Hey, I once got on a more sophicated measure of body fat percentage using electrical impedance which gave me 35% BF. My BMI was 24, putting me in the normal range. I later had the chance to to it again, at a different location, so of course a different machine which put me in 36% BF so I had to believe it.

So that started me on a diet and after reducing my BMI to 18.5 (the lower end of healthy range), my BF was 28%, which is considered obese (regardless of weight) for my age. Heck, I was told that since I am young I should be aiming for 18 - 23% BF.

I guess I was a living example of skinny-fat. Now I am fat-fat. : )

Good call on the forearm measurement...that was definitely wrong. It's actually 7.5" I believe.

glad to hear that cleared things up. 

Figuring out your body fat percentage online is terrible! For my height and weight, gender, age all that, it says my body fat percentage is close to 27%, but I hired a personal trainer a few weeks ago and she took all my proper measurements, and my body fat percentage is 32%!!! I was shocked and upset. Even she was shocked, I only weigh 165 pounds, and 32% fat is alot for weighing so little, that means I basically have no muscle and a lot of fat! Oh well, I am working on getting rid of it once and for all!

I think the best way to acquire your body make up si to go to a physician, nutritionist, or trainer that has a body composition analyzer.  My physician has a scale that calculates your fat content and muscle content based on soundwaves passing through your feet and returning to it.  She's board certified as a bariatric specialist (that's a fat doc for all you skinny girls).  At my last appt I weighed 249.  I was very upset.  I had lost 18 lbs in the previous month but really felt like I had about 80 to go.  She told me that she didn't want me to get to 160 or 140.  She said that my body make up doesn't allow for that.  She then showed my the composition reports.  I have always had 140 pounds of muscle alone when I have been on her scale.  Everyone is different.  The calculators where you put in measurements are a guideline but not necessarily accurate more of an average.  I am hoping to get to 137 before my next appointment on Tuesday wish me luck.  That will be an even thirty.

 

 

Just to comment on the last post:

At my last measurement, I was 32.6% fat, which means that as of that time, my minimum weight (at 25% fat) would be 165 pounds.  My trainer and I have discussed how our first goal will be to get me into the 160-165 pound range at 22% to 25% fat (25 pounds more to go!), THEN we will start trying to shred the muscle weight to get me into a good BMI range, based on my height (5'2.5").

As far as my trainer (and I!) is concerned, its more important to burn the fat first, THEN to worry about BMI.  I have a body type that builds muscle easily, so its easy (perhaps too easy??) to gain the muscle weight for now, and leave the BMI calcs for later.

In other words, I'm hoping to get to the appropriate BF composition before I get to an appropriate weight, per BMI.

Hope this is helpful,

--De

 

"In other words, I'm hoping to get to the appropriate BF composition before I get to an appropriate weight, per BMI."

I don't really follow this.  If you have an acceptable BF percentage, then BMI is unnecessary.  It's not unhealthy for your weight to be higher than your suggested BMI if it's muscle that's putting you there.  I'm confused.?  Why would you want to take off muscle just to reach a certain weight?

On the other side of the scale, I used an online calculator and got 4.05%, really unrealistic, I'm nowhere near an athlete and am pretty unfit, I've got quite a bit of fat so yeah, don't rely on them solely.

I'm close to 5'7" and currently weigh 160, I make sure to do free weights at least three times a week and do Turbo Jam for cardio. Everyone I who I reveal to about wanting to trim off 10-15 more pounds eyes me like I'm crazy.

Even though 160 is classified as overweight for my height, I can still see my collarbones, hips and ribs poking out and I have great arm, shoulder and leg definition. I think it really just all depends. But I know for a fact that muscle definition plays a big deal. I'm actually pretty happy at this weight and taking it slow with those last pounds.

Original Post by shandykat:

"In other words, I'm hoping to get to the appropriate BF composition before I get to an appropriate weight, per BMI."

I don't really follow this.  If you have an acceptable BF percentage, then BMI is unnecessary.  It's not unhealthy for your weight to be higher than your suggested BMI if it's muscle that's putting you there.  I'm confused.?  Why would you want to take off muscle just to reach a certain weight?

Shandy,

To clarify, being overweight (even if that weight is muscle) puts additional stress on the joints, which over time will wear them out faster than if "normal" weight is maintained.  I have a knee that's damaged--I want to reduce the stress on it as much as possible so I can avoid having surgery down the road. 

In my specific case, at 165 pounds, I expect I'll be about 25% BF, which is considered average.  But, for a 5'2" woman, 165 pounds is still 30-40 pounds overweight, depending on what statistics you read.  I'm not very confident that I'll get to 135 (a high school weight level!), but I'd want to lose another 20 pounds or so to at least get close to the correct weight range.  Sure, some of that weight will be additional fat loss (to maintain a good BF%), but some of that will also need to be muscle, just to lose the actual pounds.

Make sense?

I'm not speaking in absolutes--I don't believe in a specific weight or measure of appropriate weight.  I want to be healthy, and for me health means getting rid of this freaking chronic knee pain, which prevents me from walking and running like I want to (bit of a rant--its pretty bad this morning; gotta' do my exercises...). 

*sorry, duplicate post*

But, to get back on topic, you may want to check out the Wikipedia site on BF percentage.  Pretty interesting, and it discusses the differences b/w the various methods of measuring BF%...

We live on a military base and I had my body fat tested by the military's methods at one of my check ups. They only use body circumference and I came out 39% body fat!!! I am 5 foot 1, 120 pounds. Neck 12 inches, waist 28, abdomen also 28, wrist 5.5.

 

39% body fat. Wow. Crazy funny, don't you think?

It is very possible to have a high percentage of body fat while being a lightweight on the scale. People lose muscle as they age and as they lose weight, if they don't engage in exercises that enable them to maintain the muscle they have. (Even when not dieting, women can lose as much as 7 lbs. of muscle mass every ten years after the age of 25. And after menopause that can go up to 14 pounds of muscle mass a decade.) They also lose muscle doing catabolic exercises like long-distance running.

As has been said, though, online body-fat estimates are very unreliable. And body-fat scales are challenged by dehydration and muscle. I have a scale that offers a measurement for athletes that comes very close to my actual body-fat percentage—it uses an algorithm meant to compensate for muscle mass—but it still isn't completely accurate. If I use the regular (non-athlete) setting, though, it can be off by a huge amount. But as I say, dehydration will throw the numbers off in either case.

Original Post by petite_powerhouse:

And body-fat scales are challenged by dehydration and muscle. I have a scale that offers a measurement for athletes that comes very close to my actual body-fat percentage—it uses an algorithm meant to compensate for muscle mass—but it still isn't completely accurate. If I use the regular (non-athlete) setting, though, it can be off by a huge amount. But as I say, dehydration will throw the numbers off in either case.

I've heard about that.  Is there any way of measuring body fat that is more accurate and where dehydration won't throw the numbers off so much?