Does bmr drop as you loose

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balancedbrunette
balancedbrunette Posts: 530 Member
in Health and Weight Loss
Just wondering does bmr drop significantly as you loose weight and should i be keeping account of this figure a lot?
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  • yarwell
    yarwell Posts: 10,477 Member
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    yes, it can do. It's largely driven by fat-free mass so losing that reduces it. There's a tendency to be less active while dieting too, reducing TDEE for the same BMR.

    Generally speaking we're talking a couple of hundred calories
  • 55in13
    55in13 Posts: 1,091 Member
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    I have read about some studies that found an average of 4% to 10% drop in metabolism by overweight people on a diet. I have seen much higher figures for some poor souls that were starved to stick figures and some people promote those numbers as the norm. They are not. I have also seen people use the more reasonable numbers but claim that your metabolism will slow 2.5 times as much (appears to be possible) if you don't do X (the study I read about couldn't correlate specific causes to be at either end of the range).

    The important thing to note, IMO, is that I have never seen any medically sound study that found a point at which decreasing your input does not increase the deficit. A slowing metabolism might make that less than 1:1 at some point and there are sound reasons not to go too low, but being washed out to sea in some metabolic undertow is not reality.

    EDIT - One sort of obvious thing - it takes less energy for a 175 pound guy to run a mile than a 225 pound guy. That's simple physics; moving 2 different masses the same distance, the larger mass requires more energy. But both guys are me. Every breath I take moves a slightly lighter chest.
  • whierd
    whierd Posts: 14,025 Member
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    Yes, your BMR drops as you lose weight.
  • balancedbrunette
    balancedbrunette Posts: 530 Member
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    thanks for the replies need to go over my figures
  • paxbfl
    paxbfl Posts: 391 Member
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    Check out this calculator. You can put in different weights and see how it affects BMR.

    http://scoobysworkshop.com/accurate-calorie-calculator/

    My BMR was 2093 when I started 48 pounds ago... now it's 1875. So yeah... you have to make adjustments as you go along but it's a small price to pay. I feel so much better these days it's easy to burn more calories via exercise so not a big deal.

    Hope that helps!
  • Showcase_Brodown
    Showcase_Brodown Posts: 919 Member
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    Yes, it will lower some as you lose weight. The weight you carry around does require some energy to maintain. Lean mass will require more. I believe it is something like 6 calories a day for a pound of muscle and 2 for a pound of fat. You won't have to worry about this too much as the MFP app will adjust your recommended calories to a ballpark amount based on your current weight. As long as you are not in a severe deficit, any drop in metabolism should be fairly predictable.
  • PriceK01
    PriceK01 Posts: 834 Member
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    I read that it's a good idea to make adjustments to all of your calculations with each 10 pound change in body weight. I do it every 5, because I'm spastic like that ;)

    If you use any gadgets (HRM, fitbit, smartphone apps, etc) make sure to update those, as well :)
  • erikkmcvay
    erikkmcvay Posts: 238 Member
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    I adjust my goals every 5 lbs I lose. Helps keep you inline with what's required to keep losing.
  • 55in13
    55in13 Posts: 1,091 Member
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    If you use any gadgets (HRM, fitbit, smartphone apps, etc) make sure to update those, as well :)
    My burn for running 5 miles dropped from over 900 to under 700 when I remembered to update the app settings. Little mistakes like that are one reason I am a little leery of the "eat back exercise calories" idea (I don't do that).
  • melindasuefritz
    melindasuefritz Posts: 3,509 Member
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    yes
  • myofibril
    myofibril Posts: 4,500 Member
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    yes, it can do. It's largely driven by fat-free mass so losing that reduces it. There's a tendency to be less active while dieting too, reducing TDEE for the same BMR.

    Generally speaking we're talking a couple of hundred calories

    Pretty much this...
  • melindasuefritz
    melindasuefritz Posts: 3,509 Member
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    mine will drop from the obese category to the over weight catergory after i lose
    35 pounds... and im almost there
    MY BAD IM TALKING ABOUT BMI
    SOrry
  • linsey0689
    linsey0689 Posts: 753 Member
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    yes!
  • h9dlb
    h9dlb Posts: 243 Member
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    No. If you did little or no exercise before, and now start doing exercise such as cardio or lifting your BMR will increase, even though you are cutting !

    I think people answering yes here are confusing BMR (Basic Metabolic Rate) with BMI (Body Mass Index) and TDEE (which will decrease)
  • 55in13
    55in13 Posts: 1,091 Member
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    No. If you did little or no exercise before, and now start doing exercise such as cardio or lifting your BMR will increase, even though you are cutting !

    I think people answering yes here are confusing BMR (Basic Metabolic Rate) with BMI (Body Mass Index) and TDEE (which will decrease)
    No, we are considering that weight loss means eating at a deficit, which some studies show to cause a slight decrease in BMR and that a lower body weight means a smaller mass to keep warm, a lighter chest that rise and falls with each breath, etc. It isn't generally by a huge number but it does decrease.

    EDIT - The OP said nothing about exercise BTW. Even figuring exercise in, I have not seen any studies that show an increase in BMR while eating at a deficit.
  • h9dlb
    h9dlb Posts: 243 Member
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    Are you seriously denying that if you start an exercise regime or increase an exercise regime your metabolism will not increase, irrespective of a calorie deficit and fat loss? Otherwise what's the point in doing any exercise!
  • 55in13
    55in13 Posts: 1,091 Member
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    Are you seriously denying that if you start an exercise regime or increase an exercise regime your metabolism will not increase, irrespective of a calorie deficit and fat loss? Otherwise what's the point in doing any exercise!
    The point is you burn calories while you do it and there is the potential of gaining muscle which will increase BMR, but the subject of whether or not you can gain muscle while eating at a deficit is pretty debatable in itself. Given the OP's question, which does not mention exercise but does ask about weight loss (which we assume means a calorie deficit and fat loss), I was not answering irrespective of calorie deficit and fat loss; that was the context of the question. Anyway, the info I have seen leads me to believe that some people can get a slight muscle gain in deficit. Whether that offsets the lowered BMR due to the weight loss I cannot say for sure, but I don't think so. I have an open mind though; please cite your source.
  • h9dlb
    h9dlb Posts: 243 Member
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    The original question was "Does BMR drop as you lose weight?". Several people answered yes. My point is this is not necessarily the case, because if you exercise while cutting, BMR will increase.

    Calorie burn just does not come from the exercise itself, but also comes from the "afterburn" in the hours post exercise when the metabolism is increased whilst the damaged muscles are being repaired, depleted oxygen is being replaced, phosphates are turned into creatine, fat stores are broken down into free fatty acids and hormones are put in check. For your body to do this requires energy, hence fat burning and increased metabolism. The after burn from heavy weight training is much greater (lasting upto 36 hours) than the afterburn from cardio, which is only a few hours.

    As for citations, its a bit too late for me to go into it now but google "EPOC" - Exercise Post Oxygen Consumption which explains why metabolism is increased after strenuous exercise, irrespective of being on a cut or not.

    By the way many congrats on the 50lbs
  • 55in13
    55in13 Posts: 1,091 Member
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    Thanks! I feel a lot better without that extra weight. Still some to go but I see the light at the end of the tunnel.

    I have looked into EPOC some as I have tried to do HIIT from time to time. There is a pretty good WikiPedia article (really good compared to some, this one is almost purely a bunch of cited study quotes):
    http://en.wikipedia.org/wiki/Excess_post-exercise_oxygen_consumption
    It backs up your 36 hour claim and even raises you 2 hours. :smile:

    I say "tried to do HIIT" as I am not sure I ever really do it hard enough to really make that much of a difference. I know I am trying to put the cart before the horse to some degree; it seems like this awesome way to get your metabolism going so you can get in better shape, but you need to be in pretty good shape to do effective HIIT.

    But we digress; the OP's question didn't mention exercise at all, just weight loss. My BMR has dropped as I lost weight and I think the OP's will also.
  • h9dlb
    h9dlb Posts: 243 Member
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    HIIT gets easier the more you do it, and is great for fat loss, and takes such little time compared to steady cardio, I also find it less boring (I hate cardio). You only have to do 20 mins. Perseverance and consistency is the key

    If you are struggling just sprint for 30 seconds then walk for a minute and a half. As you progress increase the sprints to 45 seconds and reduce the walking to a minute. Then when you get fitter, drop the walking and do a light jog for 30 seconds. Alternatively (assuming you are using a treadmill) in between sprints walk on a 12% incline.

    Treadmill is best for HIITS, but if you are finding it really difficult, do it on a bike, rower or kettlebell circuits, whatever you are most happy doing, as training shouldn't be a chore / de-motivating

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