Body Fat Percentage

michedarnd
michedarnd Posts: 207 Member
edited October 2 in Fitness and Exercise
How do various people measure their body fat percentage? I have a scale that ostensibly measures it, but it seems to be greatly affected by water weight, or the phase of the moon, or something. For instance, yesterday, it was 41. This morning, it's 37. Now, I've been exercising, so I can believe that it is falling (it was higher than either when I started), but how do I know what it REALLY is?

Replies

  • Kalrez
    Kalrez Posts: 655 Member
    I take body measurements and use http://www.healthcentral.com/cholesterol/home-body-fat-test-2774-143.html

    It may not be 100% accurate, but at least it is a consistent way for me to see how the percentage is changing.
  • jennadaniele
    jennadaniele Posts: 40 Member
    Hi there! I did a basic measurement. I'm sure this is not totally accurate, but you can use it as a meter to see where you start and where you end up. Also, you can use it against what your scale tells you! Here's the link::

    http://fitbie.msn.com/fit_tools/body_fat?weight=178.4&waist=32&wrist=2.5&hips=41&forearms=6&gender=2&calc=true
  • Acg67
    Acg67 Posts: 12,142 Member
    calipers/tape measure

    i'd get a Bodpod test if there was somewhere within 20mi of me though. i'm looking into getting a DEXA scan to get a good reading since i don't think my bf is as low as my caliper readings are
  • Azdak
    Azdak Posts: 8,281 Member
    With those scales, even a good one, two things to keep in mind:

    1. Be as consistent as possible when you take your readings--same time of day, hydration status, etc.

    2. See the numbers more of a trend line than precise measurements. In other words, look at the avg readings over several days to get a general sense of where you are.

    Body fat scales are not precise--the numbers will fluctuate a lot, but they should be within a certain "range" and that "range" should move downward if your body fat is actually decreasing. Essentially, for these scales, there is little or no difference between 41% and 37%.
  • Azdak
    Azdak Posts: 8,281 Member
    I take body measurements and use http://www.healthcentral.com/cholesterol/home-body-fat-test-2774-143.html

    It may not be 100% accurate, but at least it is a consistent way for me to see how the percentage is changing.

    The % number might be off, but the absolute measurements should be quite accurate.
  • Fiyero
    Fiyero Posts: 31
    Mine only varies by a couple tenths each day assuming a constant weight. My best advice would be to take it first thing in the morning and try to not let up on water consumption as your body holds onto water if it is not getting enough. Also, women may take on extra water just prior to menstruation which can throw the readings a bit.
  • Acg67
    Acg67 Posts: 12,142 Member
    i think BIA scales can be useful for tracking trends but in terms of accuracy...

    Changes in body composition during weight loss in obese subjects in the NUGENOB study: comparison of bioelectrical impedance vs. dual-energy X-ray absorptiometry.

    Verdich C et al. Diabetes Metab. 2011 Jun;37(3):222-9.

    "RESULTS:

    At baseline, BIA significantly overestimated FFM and underestimated FM (by 1-3 kg on average) compared with DXA, and the limits of agreement were wide (mean ± 7-8.5 kg). "


    A comparison of dual energy X-ray absorptiometry and bioelectrical impedance analysis to measure total and segmental body composition in healthy young adults.

    Lehy S et al. Eur J Appl Physiol. 2011 May 26

    "BIA was found to underestimate the percentage total body fat in men and women (p < 0.001). This underestimate increased in men with >24.6% body fat and women with >32% body fat (p < 0.001). Fat tissue mass in the trunk segment was overestimated by 2.1 kg (p < 0.001) in men and underestimated by 0.4 kg (p < 0.001) in women. BIA was also found to underestimate the fat free mass in the appendages by 1.0 kg (p < 0.001) in men and 0.9 kg (p < 0.001) in women. Compared to dual energy X-ray absorptiometry, bioelectrical impedance analysis underestimates the total body fat mass and overestimates fat free mass in healthy young adults."
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