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Body fat verses body weight

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Could some one explain this one to me yesterday I stood on the scales after what I thought was a good week for me but I lost only a pound but the bit that confused me was I lost 3%body fat

Replies

  • kimny72
    kimny72 Posts: 16,012 Member
    edited February 2017
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    Losing a lb a week is awesome progress! And scales don't do a great job of measuring body fat, so dont put too much importance on that number.
  • faidwen
    faidwen Posts: 131 Member
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    I have lost 150 lbs. But now that I work out, I am actually gaining weight, but still slimming down. Body weight, as per the scale is not a TELL-TALE sign of improvement. Muscle, is more dense, so it takes up less space to weigh the same amount. So although I am shedding fat, or have shed fat, I am now gaining some weight as-per-the scale numbers, yet still reducing my measurements etc etc....

    SO, don't rely solely on the scale. Rely more on how you FEEL, and how things LOOK and FIT!!!!!

    AND HAVE FUN!!!!
  • CafeRacer808
    CafeRacer808 Posts: 2,396 Member
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    Your scale uses bioelectric impedance to measure body fat %, which is a very inaccurate and unrealiablemethod. Frankly, you'd be better off not even paying attention to the BF% reading your scale is giving you. I disabled that feature entirely on my scale. Body calipers (if used properly) will be more reliable, but getting either a DEXA scan or a hydrostatic weigh-in will be most accurate.

    With regard to that pound you lost, it's important to remember that weight loss is not linear. Even if you ate at or under your daily calorie goal every day for a month, you'd find that some weeks you lost more than others. It's also very likely to have some weeks during which you don't lose any weight at all. Just trust the process and keep logging your food.
  • Cherimoose
    Cherimoose Posts: 5,208 Member
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    Assuming your scale was accurate - which sometimes they are - it means you gained some non-fat weight. For example, water weight from consuming extra carbs or sodium - pretty common on weekends. So it's useful to track your weight trend over time (Trend Weight, Weight Grapher, Libra, etc). :+1:
  • mzb123
    mzb123 Posts: 6 Member
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    Thanks everyone
  • Chieflrg
    Chieflrg Posts: 9,097 Member
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    Scales are highly inaccurate on body fat percentage.
  • MontyMuttland
    MontyMuttland Posts: 68 Member
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    There is a tendency to blame measuring devices for being inaccurate, and some definitely are if they are poorly made, but actually a lot of modern scales can give pretty accurate results.
    The problem is that people are inaccurate, or more exactly our bodies are constantly changing in ways which can affect the measurement of fat percentage in the body.
    Our weight fluctuates throughout the day, as does our hydration levels and if you were to measure yourself on the scales several times throughout the day, the results would vary. As a consequence, even though your actual body fat percentage won't have changed (at least not by much), the read-out will be different.
    You can't make it perfect, but you can reduce the variation by always taking your measurements at a fixed time of day. For example just before your evening meal when your body is usually pretty well hydrated but you don't have a tummy full of undigested food.
    It's best not to get too hung up on any one fat percentage reading though, instead record your results on a weekly basis and review your progress on a monthly basis.
    That may sound like slow work, but weight-loss isn't an easy fix, it takes time and effort to achieve the results you want.
    A second point to make is that it is entirely possible for your body fat percentage to decrease without any physical weight loss, specially if you are taking some exercise as part of your weight-loss plan and/or eating plenty of protein.
    It's not at all unusual for gains in muscle tissue to out-weigh or cancel out losses from fat burning, but this is a good thing not a bad thing.
    Apart from the health benefits of having more muscle tissue in your body, it also takes up less space in your body than fat, so you'll still be getting smaller even if your physical weight isn't going down much.
  • kimny72
    kimny72 Posts: 16,012 Member
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    Yeah, but there's no way OP lost 3% body fat and gained the equivalent muscle in a week.
    There is a tendency to blame measuring devices for being inaccurate, and some definitely are if they are poorly made, but actually a lot of modern scales can give pretty accurate results.
    The problem is that people are inaccurate, or more exactly our bodies are constantly changing in ways which can affect the measurement of fat percentage in the body.
    Our weight fluctuates throughout the day, as does our hydration levels and if you were to measure yourself on the scales several times throughout the day, the results would vary. As a consequence, even though your actual body fat percentage won't have changed (at least not by much), the read-out will be different.
    You can't make it perfect, but you can reduce the variation by always taking your measurements at a fixed time of day. For example just before your evening meal when your body is usually pretty well hydrated but you don't have a tummy full of undigested food .

    So you're saying the problem isn't the scale, it's your body? Scales are inaccurate for body fat % because of the way they measure, which allows a lot of other variables to get in the way of being accurate. Yes they do work as designed, but they were designed to do something innacurately. I'm sorry I don't mean to be argumentative, but that just seems like an odd way to look at it.

    I also wouldn't suggest weighing before dinner. Firstly I don't think it's necessarily common for someone stomach to be empty at this time. And second, there are lots of other factors at that point in the day that could make your weight measurement more variable. So you would be giving up consistency in the more important metric, wouldn't you?
  • MontyMuttland
    MontyMuttland Posts: 68 Member
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    kimny72 wrote: »
    Yeah, but there's no way OP lost 3% body fat and gained the equivalent muscle in a week.
    There is a tendency to blame measuring devices for being inaccurate, and some definitely are if they are poorly made, but actually a lot of modern scales can give pretty accurate results.
    The problem is that people are inaccurate, or more exactly our bodies are constantly changing in ways which can affect the measurement of fat percentage in the body.
    Our weight fluctuates throughout the day, as does our hydration levels and if you were to measure yourself on the scales several times throughout the day, the results would vary. As a consequence, even though your actual body fat percentage won't have changed (at least not by much), the read-out will be different.
    You can't make it perfect, but you can reduce the variation by always taking your measurements at a fixed time of day. For example just before your evening meal when your body is usually pretty well hydrated but you don't have a tummy full of undigested food .

    So you're saying the problem isn't the scale, it's your body? Scales are inaccurate for body fat % because of the way they measure, which allows a lot of other variables to get in the way of being accurate. Yes they do work as designed, but they were designed to do something innacurately. I'm sorry I don't mean to be argumentative, but that just seems like an odd way to look at it.

    I also wouldn't suggest weighing before dinner. Firstly I don't think it's necessarily common for someone stomach to be empty at this time. And second, there are lots of other factors at that point in the day that could make your weight measurement more variable. So you would be giving up consistency in the more important metric, wouldn't you?

    I wouldn't normally take this class, since the point of responding to the OP's post was to help them understand the deal with body fat readings on weighing scales, but since you've pretty much rubbished my comments kimny72 I think I should respond.
    Scales which measure body fat percentage are not designed to be inaccurate, that's just a nonsense statement.
    If you actually understood anything about how they work, you would appreciate that one of the key factors in getting an accurate measurement is having an adequately hydrated body, something you would hope to be the case around dinner time when someone has been up for several hours.
    In addition, nowhere did I state that you need to have an empty stomach or imply that someone would have an empty stomach at that time of day. It would be likely they hadn't just eaten a large amount just before dinner, which would also mean it would be likely they didn't have a tummy full of undigested food.
    The point being made was that the nature of our constantly varying bodies makes it hard to obtain consistent readings for body fat percentage, but that you can improve things by taking the measurement when you are well hydrated and haven't eaten for a few hours.
    For the record, well hydrated doesn't mean drinking lots of water just before measuring, it means drinking plenty of water throughout the day.