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BMI question for LCHF & Keto dieters

BaconSan2
BaconSan2 Posts: 260 Member
edited December 2024 in Social Groups
When I started this diet almost 3 weeks ago my BMI was 55.6 since then I have lost 10 pounds and my BMI is 55.8. What gives am I burning up organs & lean muscle mass? Aurghhhh. I have a Fitbit Aria scale that is telling me my BMI. :(

Replies

  • Phrick
    Phrick Posts: 2,765 Member
    it's the scale. Devices like that that use bioimpedance to "calculate" your BMI are horribly inaccurate and can be wildly skewed just by how hydrated you are on any given morning.
  • Phrick
    Phrick Posts: 2,765 Member
    Scales are good at one thing: giving your weight. Everything else that the fancy-dancy ones claim to be able to do well, they in reality do very poorly (BMI, body fat %, etc)
  • sammyliftsandeats
    sammyliftsandeats Posts: 2,421 Member
    Is it tell you your BMI or your Bodyfat %? They are two different things.

    Also, the scale is inaccurate as @Phrick mentioned.

    The more accurate measures cost more money such as a Bodpod or a DEXA scan.
  • Sabine_Stroehm
    Sabine_Stroehm Posts: 19,251 Member
    samanthaluangphixay wrote: »
    Is it tell you your BMI or your Bodyfat %? They are two different things.

    Also, the scale is inaccurate as @Phrick mentioned.

    The more accurate measures cost more money such as a Bodpod or a DEXA scan.

    ^^^^This.^^^^

    Your BMI is a simple mathematical formula.
    http://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm
    If you lose weight, it goes down. Period.

    The scale is attempting to tell you your body fat, not body mass. And they are wildly inaccurate.
    I don't stay on the scale long enough for it to give me the number, as I know it's meaningless. I follow the weight number.
  • Sunny_Bunny_
    Sunny_Bunny_ Posts: 7,140 Member
    Yeah, something is either off with your understanding reading the numbers, like it's actually body fat%... Or one of the calculations is wrong.
    BMI is calculated based on height and weight.

    Body fat % on those scales varies constantly. Gut contents and water will affect the measurement too.
    What I do to get the most accurate measurement possible from mine is take a reading every morning for a week then calculate the average. Then I compare weekly averages to previous ones. Same with skeletal muscle measures. It's still just a ballpark measurement, but close enough to be useful as a measure of long term progress.
  • BaconSan2
    BaconSan2 Posts: 260 Member
    OK thanks everyone. That is very good to know.
This discussion has been closed.

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