Is It Possible To Lose 1% Body Fat In A Week?

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I never paid much attention to the body fat part of my scale, but I stepped on it today to compare just out of curiosity. Last week I weighed 140.8 pounds with 26% body fat. This morning(exactly a week later) I weighed exactly the same but didn't pay attention to the body fat %. I stepped on it again just now and it was at 142.6 (I have a full belly) but it said my body fat is now 25%. Is this possible to do in a week? Could I really have lost that much body fat and increase in muscle? I was looking how accurate body fat scales were online and they said although they may not be exactly accurate, if they measure change correctly it's still a good indicator, but I'm still a little skeptical.

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  • cmbneeley
    cmbneeley Posts: 160 Member
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    i've heard they depend on hydration levels a lot and aren't very accurate.
  • HollyRutledge
    HollyRutledge Posts: 250 Member
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    Yes its possible I have done it...very hard work, but possible
  • krd82
    krd82 Posts: 53
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    I think the reason it is reading less body fat is because your full belly is making it read 2lbs heavier which changes the percentage of fat.
  • rileysowner
    rileysowner Posts: 8,224 Member
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    For that sort of Body Fat analysis to be even remotely accurate you need to measure at pretty much the same time with your body in the same condition. They actually measure the water in your body, and then use a formula to calculate fat %. That means it can change based on how hydrated you are. If you measure yourself every morning after using the toilet (assuming you drink about the same amount of water every day) your hydration level would be pretty close, and the numbers would be better. However, even then the margin of error is pretty big on them.

    As to the question, losing 1% would depend on how much 1% is which depends on how much you weigh, how much of it is fat, and a whole bunch of other things. It would require a lot of work though, and probably just the right sort too.
  • ohohraptor
    ohohraptor Posts: 205 Member
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    I think the reason it is reading less body fat is because your full belly is making it read 2lbs heavier which changes the percentage of fat.

    Maybe I'll check tomorrow and see what it says. To be honest I don't really care whether it's exactly accurate or not, but it would be cool if it measured changes correctly, that way I'd know my body fat was at least going down even if the scale wasn't moving.
  • ohohraptor
    ohohraptor Posts: 205 Member
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    For that sort of Body Fat analysis to be even remotely accurate you need to measure at pretty much the same time with your body in the same condition. They actually measure the water in your body, and then use a formula to calculate fat %. That means it can change based on how hydrated you are. If you measure yourself every morning after using the toilet (assuming you drink about the same amount of water every day) your hydration level would be pretty close, and the numbers would be better. However, even then the margin of error is pretty big on them.

    As to the question, losing 1% would depend on how much 1% is which depends on how much you weigh, how much of it is fat, and a whole bunch of other things. It would require a lot of work though, and probably just the right sort too.

    I just calculated it and 1% of my body fat would only be .366 of a pound. That would actually be kind of disappointing, since according my MFP I should be losing 1.2 lbs a week. :/
  • mini_girl7
    mini_girl7 Posts: 32 Member
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    I am somewhat skeptical of the body fat scale results -- I have a Tanita brand bought back in 2004-2005. My body fat has always registered higher on the scale than when calipers are used. Also, my body fat registers at a higher percentage in the morning than at night, which seems strange -- weigh less in the morning & have a higher BF % and weigh more at night with a lower BF %. What I do to try to compare apples to apples is weigh the exact same way each time -- early morning when I first get up and after i have emptied my bladder -- gives you the same parameters each time you weigh.

    Hopefully technology has improved since i purchased my scale and things are more accurate -- but my scale says I'm around 40% BF and the calipers done by a fitness person at the gym say 31% -- big discrepancy! Take it with a grain of salt and get other testing done to give you more information -- good luck!
  • ohohraptor
    ohohraptor Posts: 205 Member
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    I am somewhat skeptical of the body fat scale results -- I have a Tanita brand bought back in 2004-2005. My body fat has always registered higher on the scale than when calipers are used. Also, my body fat registers at a higher percentage in the morning than at night, which seems strange -- weigh less in the morning & have a higher BF % and weigh more at night with a lower BF %. What I do to try to compare apples to apples is weigh the exact same way each time -- early morning when I first get up and after i have emptied my bladder -- gives you the same parameters each time you weigh.

    Hopefully technology has improved since i purchased my scale and things are more accurate -- but my scale says I'm around 40% BF and the calipers done by a fitness person at the gym say 31% -- big discrepancy! Take it with a grain of salt and get other testing done to give you more information -- good luck!

    Does it seem to measure changes correctly though? Like as you lose weight, is the percent going down as well, even if the actual number isn't correct?
  • mini_girl7
    mini_girl7 Posts: 32 Member
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    My BF has gone down 2%, according to the scale and that is with a 9 pound weight loss -- i haven't done the calipers in a long time -- i need to! Like I said, i think the scale is interesting, but I don't put a lot of stock in the BF number, at least on mine! :smile:
  • ohohraptor
    ohohraptor Posts: 205 Member
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    My BF has gone down 2%, according to the scale and that is with a 9 pound weight loss -- i haven't done the calipers in a long time -- i need to! Like I said, i think the scale is interesting, but I don't put a lot of stock in the BF number, at least on mine! :smile:

    Good to know! Like I said, I'm not as concerned with the actual number (I'll just get that done at the gym from time to time) as it measuring changes correctly. I get so discouraged when the scale doesn't move like it did this week, but as long as my scale is saying my body fat went down, I can relax a little. :)
  • TrainingWithTonya
    TrainingWithTonya Posts: 1,741 Member
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    140.8 x 26% = 36.608 pounds of body fat
    142.6 x 25% = 35.65 pounds of body fat

    So, just slightly less then 1 pound of fat loss. Yes, that is possible in a week. That being said, like was already mentioned, it is only accurate if you weighted and measured your body fat at about the same time of day in similar clothing and had similar hydration levels.
  • ohohraptor
    ohohraptor Posts: 205 Member
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    140.8 x 26% = 36.608 pounds of body fat
    142.6 x 25% = 35.65 pounds of body fat

    So, just slightly less then 1 pound of fat loss. Yes, that is possible in a week. That being said, like was already mentioned, it is only accurate if you weighted and measured your body fat at about the same time of day in similar clothing and had similar hydration levels.

    Oh, I totally did the math wrong when I calculated that. :o A little less than a pound isn't that bad (assuming it was even close to correct in the first place).