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Losing weight but body fat percentage is going up?

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Admittedly I'm using a Fitbit Aria scale. Each morning I weight myself and I've been watching both my weight and body fat percentage go down. There's a lot of fluctuation, but the overal trend was downward.

But now recently in the last two weeks or so my weight has continued on trend but my body fat percentage has either stalled or gone back up. My eating habits haven't changed. I am running more. I'm just wondering if this has happened to anyone else? Should I change something? Or will it eventually line back up if I hold course?
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Replies

  • TimothyFish
    TimothyFish Posts: 4,925 Member
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    You're losing nothing but muscle, man.

    Either that or your scale doesn't work.
  • sgthaggard
    sgthaggard Posts: 581 Member
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    You're losing nothing but muscle, man.

    Either that or your scale doesn't work.
    Or more muscle than fat but, essentially, that.

  • jadezia
    jadezia Posts: 45 Member
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    Without strength training to keep your muscle, you may be losing muscle mass. I can't say for sure, but that may be what's happening.
  • geotrice
    geotrice Posts: 274 Member
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    One of those is probably true, or both. I expected to lose some muscle while dropping weight. But I was okay with it as long as the fat was going too. I'm not freaking out about it. At least not yet.

    Assuming the scale is working, is it normal to go through alternating periods of losing muscle and fat? From what I read I thought I'd be losing both at the same time.

    In the mean time I guess I need to increase the amount of weight training to minimize the muscle lost.
  • mrsaha
    mrsaha Posts: 9 Member
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    Have you been staying well hydrated? Those body fat scales aren't very accurate, and the readings can change if you are dehydrated. If you have been increasing your exercise, have you also been increasing your fluid intake to counter what you lose in perspiration?
  • rileysowner
    rileysowner Posts: 8,262 Member
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    The scales that measure BF% are not very accurate. Even from measurement to measurement they often do not remain accurate to themselves. Also, hydration has a huge effect on their measurement of BF%. If your hydration level has changed a lot, say because you are drinking the same amount by sweating out more from more running, it will affect the calculation of your BF%.
  • juggernaut1974
    juggernaut1974 Posts: 6,212 Member
    edited March 2015
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    Combination of notorious inaccuracy of those scales, and math.

    Even IF you assume the scales were 100% accurate (and that's a GIANT "If")

    You start at 200 lbs, 25% BF (just as an example). So you have approximately 150 lbs lean mass, and 50lbs of fat

    You lose 10 lbs - of which 2 lbs was fat, 8 lbs was lean mass

    You now weigh 190, with 48 lbs of fat, yielding a BF% of 25.3%
  • cityruss
    cityruss Posts: 2,493 Member
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    Dirty feet.
    Moist feet.
    Temperature.
    Humidity.
    Moon phase.
    Unicorns.

    These all effect the bioelectrical impedance analysis these scales use.

    I'm afraid assuming the scale is working will not do. Inaccurate is not the word.
  • geotrice
    geotrice Posts: 274 Member
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    Hmm...excellent points. Hydration could be explaining the divergence in the numbers. I am drinking lots of fluids (water, coffee, diet sodas). Perhaps I'll try to watch the amount of fluids intake in before going to sleep.

    Now normally the day-to-day numbers for both would fluctuate. It just seemed odd that suddenly the weight and bf trends were tracking differently. Overall, the weight is coming off and I'm seeing positive results in the mirror and in my (new and smaller) clothes.
  • geotrice
    geotrice Posts: 274 Member
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    cityruss wrote: »
    I'm afraid assuming the scale is working will not do. Inaccurate is not the word.
    I think you're correct. Truly I think the bf is a bit of a gimmick on home scales. I was using it as a general point of reference. Like, "oh my weight is going down. Oh and look at that. My supposed bf% is going down too. Bonus points!"

    I guess my original post was trying to get at losing muscle and fat at the same time versus losing it at different rates.

    By the way thanks all for the replies! The community here on MFP has always been a helpful source of info and motivation.
  • PAV8888
    PAV8888 Posts: 13,993 Member
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    Don't go into a panic quite yet. Let's tackle this from multiple angles.

    What are you stats? Height, current weight, target weight, RATE OF WEIGHT LOSS, are you vegetarian?, grams of protein you've eaten on average during the past 7/15/30 days?

    What do you think your bodyfat % is, and what is the % difference that the Aria is showing you? Is the aria showing a 0.1% difference or a 5% difference?

    Have you reset the Aria recently?
    (remove the leftmost battery for a second or two, it will show you your wifi name and ask you to tap to change; if you don't do anything, the next time you step on it will perform the "hi-step off-thinking" full calibration routine; probably take an additional 2 readings in a row at that point).

    Are you weighting yourself in a similar state? (preferably without having consumed anything and after eliminating and not wet from the shower and at relatively similar times during the day)

    Can you afford to invest in a more reliable method of bodyfat estimation than the incredibly flawed bio-impedance analysis scales? (hydrostatic weighting, DEXA scan, Air-Displacement Plethysmography, depending on where you live price and availability may affect your choice).
  • geotrice
    geotrice Posts: 274 Member
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    ceoverturf wrote: »
    Combination of notorious inaccuracy of those scales, and math.

    Math, that meddlesome scoundrel.
  • sgthaggard
    sgthaggard Posts: 581 Member
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    Also, make sure you are measuring at the same time every day - first thing in the morning post-bathroom, pre-breakfast is best.

    I have an Aria as well. Something I really like about it is that I can link it to trendweight.com - it will show you your overall trend in weight, body fat%, lean mass & fat mass.
  • virelay129
    virelay129 Posts: 43 Member
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    Increase your weight training a notch, and focus on getting you protein macros. :) Good luck!
  • mcgruff_cu
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    Fluctuation is normal, you're correct to focus on the trend. Give it time, and don't make drastic changes too quickly. Losing some muscle while on a caloric deficit is almost inevitable for someone who is already in decent shape. People who are very over weight and/or those without much muscle (those who haven't worked out in years, or ever can absolutely burn fat and gain muscle at the same time with diet and exercise. The leaner you become the harder it will get to do this.

    If the only exercise you're doing is cardio (running) there is a good chance you could be losing muscle. Without weight training you are basically telling your body that you need to be a lean-mean-running-machine. It will happily respond and become more efficient by shedding off some of that heavy unnecessary muscle (along with the fat). If your interested, try researching type 1 and type 2 muscle fibers. One is for endurance (slow twitch) and the other for power/strength (fast twitch). Running doesn't require fast twitch muscles (as much) so those may get cannibalized to make the running process more efficient.

    Apart from weight training, make sure you keep your protein levels up (in the area of 1 gram per pound of body weight IMHO). I've read studies where high protein diets significantly reduced muscle loss in dieters even in the absence of weight training.

    Lastly, be patient with your weight loss and shoot for no more that 500-1000 calorie per day deficit. The longer you take to loose the fat, the more likely it is to stay off and the less likely you are to loose significant muscle mass in the process.

    One more thing about the fat percentage. If you're using a scale (or handheld) bioimpedence device (one that uses metal plates to send electric current through you) be mindful that these are fairly inaccurate and best for gauging trends. Try to take measurements at the same time of day and under the same conditions (hydration level, time since last meal, etc.). If measuring through your legs (using a scale) you may get significantly lower (and inaccurate) % readings after a leg workout (such as running) because all of the extra blood in those muscles (sometimes its fun to do it for a moral boost though :-) ). If you've been working out for a while and getting leaner, see if the device has an "athlete" mode. The calculations are based on averages taken across a sample population. So the further you are from the average (whether fit or overweight) the less accurate the calculation will become.

    Hope that helps. Good luck and keep up the hard work!
  • betuel75
    betuel75 Posts: 776 Member
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    I wouldnt bank of the BF % from a scale. I have a Weight Watchers scale with all that good stuff and it says my BF % is 14.7 and i know for sure that im way below that in bodyfat %s. Use the looking in the mirror and pinching test to see body fat drop.
  • jennifershoo
    jennifershoo Posts: 3,198 Member
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    Too much cardio, not enough weight training.
  • ninerbuff
    ninerbuff Posts: 48,747 Member
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    Just a note: If a person is just doing cardio only YET they are supplying enough protein and carbs in the body, muscle loss isn't going to be that significant. To lose muscle, there's usually a big deficit and lack of macros to support muscle maintenance.

    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition

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  • geotrice
    geotrice Posts: 274 Member
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    mcgruff_cu wrote: »
    If the only exercise you're doing is cardio (running) there is a good chance you could be losing muscle. Without weight training you are basically telling your body that you need to be a lean-mean-running-machine. It will happily respond and become more efficient by shedding off some of that heavy unnecessary muscle (along with the fat). If your interested, try researching type 1 and type 2 muscle fibers. One is for endurance (slow twitch) and the other for power/strength (fast twitch). Running doesn't require fast twitch muscles (as much) so those may get cannibalized to make the running process more efficient.

    Apart from weight training, make sure you keep your protein levels up (in the area of 1 gram per pound of body weight IMHO). I've read studies where high protein diets significantly reduced muscle loss in dieters even in the absence of weight training.

    Oooh. This is interesting. I forgot about the different muscle fibers. Thanks for the info.
  • geotrice
    geotrice Posts: 274 Member
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    Thanks Ninerbuff. I'll double check my nutrition balances and my protein intake. I've mostly been doing cardio so far in prep for my first half marathon.