body fat percentage and bioelectrical impedence

[treelizard]

All right, so what's the deal with these body fat percentage scales? I bought one and last night after work it said I was at 22.6%, and then this morning it said I was 26.1%. The blonde chick at the gym with the calipers said I was at 23.6%, but I'm not sure I trust her measurements because she measured above my knee for the thigh measurement.

Anyways, I was wondering if anybody has gotten accuracy from these scales? I know that when it had me at 22.6% my body water percentage was at 51, and this morning's 26.1% score my body water was at 49.3%. What is a healthy body water percentage, and what is an accurate one? The only thing I can find says that women should be 45-60 but it's annoying me that this scale fluctuates so much.

I'm going to get the Futurex analysis and average the three, I guess. I tried to research these three methods online (bioelectrical impedence, near-infrared technology and skin-fold calipers) and it seemes like almost all of them are considered inaccurate by various experts. Also the % that people say is healthy also varies wildly, with the American Council of Exercise saying 18-22 for women, and the NIH/WHO guidelines saying a healthy range for women is 21-33.

Update: I called the customer service number for the scale and they said if the fluctuation is more than +/- 3% the scale is broken. So much for Taylor, I think I will stick with Tanita from now on.

[muaythaiguy15]

Give it a a 5% range. None are 100 percent accurate. A glass of water can throw it off. I dont know why people really bother with that stuff. If you think youre fat, workout. If youre happy, then continue working out or stop if you want to. Oh well...

[treelizard]

I like the idea of setting goals and seeing results. Also I think it's a better measure than just weight, because your weight can go up and BFP go down since muscles weigh more than fat, etc.

Give it a a 5% range. None are 100 percent accurate. A glass of water can throw it off. I dont know why people really bother with that stuff. If you think youre fat, workout. If youre happy, then continue working out or stop if you want to. Oh well...

[muaythaiguy15]

Ah good point mi amigo. The only reason I ever knew mine was how much I could cut and stuff for wrestling, never thought of it for goals.

[THT]

With those bodyfat scales you need to use it everyday at around the same time and average it out. Also, do it after the shower, after you've dried everything but the bottoms of your feet. The little bit of moisture improves the electricity penetrating your skin. I think that if you try this for a while you will get a good idea of where you're at. I have one, by Taylor, and after I got on a set routine and did the math I have been happy with the info I'm being provided.

[Eyegouge]

yo, tree, what i've heard about healthy BFP's for women from hardcore athletes is that chicks shouldn't drop below 10% and dudes shouldn't drop below 2%. That's what I've heard from the wrestlers and the track pps here on the college teams.

[treelizard]

Interesting, I've heard below 15% for women and they stop menstruating.

yo, tree, what i've heard about healthy BFP's for women from hardcore athletes is that chicks shouldn't drop below 10% and dudes shouldn't drop below 2%. That's what I've heard from the wrestlers and the track pps here on the college teams.

[Eyegouge]

really?....i'm sure if you dropped it low enough at a young age, you could stop the onset of menstruation, some rhythmic gymnasts do it, i know that 4 a fact.

I haven't heard that you could stop it after it's started with malnurishment though.

the girl that told me 10% is a hurdler for Easter Illinois Unv. track team....she said her BFP is 14%....I guess i could ask her next time i'm in charleston if she's menstruating...lol

HI Laura!....hey quick question....are you menstruating??? WHAT?!..lol

my g/f says that she's pretty sure she's below 15% and shes....damn i hate spelling that big ass word....having her period....

[treelizard]

From Andrew Weil's website (not that I believe everything he says.)

How Much Body Fat Do We Need?

How low is too low for body fat percentage in women? I’m a kickboxer and karate student and have gone from 25% to 15% body fat in 8 months. I’m 25 years old.

-- Tess Jenkins


Answer (Published 04/19/2002)

We carry two kinds of fat in our bodies, essential fat which is stored in small amounts in bone marrow, organs, the central nervous system and muscles, and is needed for the normal, healthy functioning of all these body systems, and “storage” fat, which is stocked for energy. For men, essential body fat makes up about three percent of total body weight. For women, the percentage is higher – about 12 percent – because it includes amounts in the breasts, pelvis, hips and thighs believed necessary for normal female reproductive function.

For a woman of 25, a healthy range of body fat would be between 21-32 percent. This can increase slightly with age, to 23-33 percent for women between 40 and 59 and to 24 - 35 percent for those over 60. The healthy ranges in men are from 8-19 percent for those between the ages of 18-39, from 11-21 percent for those aged 40 to 59 and 13-24 percent for those over 60.

We now believe that, for women, the minimum body fat percentage should be between 13 and 17 percent although there’s no hard and fast “rule” on what is too low for an individual. Keep in mind that there are several ways to measure body fat, and some are notoriously inaccurate, so the ranges and absolute numbers may vary. You may be able to tell when your body fat is too low by whether or not you’re menstruating regularly. If your periods stop, nature may be telling you that you don’t have enough body fat to nurture a fetus should you become pregnant. By turning off your menstrual cycle, your body is telling you that you are (temporarily) infertile. Please don’t think of this as a convenient method of birth control – it isn’t. You need normal hormonal function for more than just menstruation and fertility. For example, the health of your bones also depends on circulating levels of estrogen, the principal reproductive hormone in women.

My personal trainer, Dan Bornstein, CPT, tells me that when body fat percentage gets too low, energy levels and exercise performance decline. So does tolerance for cold. However, in general, as long as you continue to menstruate and as long as your energy level remains intact, your body fat percentage is probably OK. I would encourage you to gain a few pounds if your periods stop or become irregular or if you lack your usual energy.

Dr. Andrew Weil