Is BMR seriously accurate?

You use energy no matter what you're doing, even when sleeping. The BMR Calculator will calculate your Basal Metabolic Rate (BMR); the number of calories you'd burn if you stayed in bed all day.
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BMR is 1665.5.

Seriously, I don't think is right. There's no way I'd burn over a thousand calories doing NOTHING. Seriously. That can't be accurate.
I'm about 5'6", 25, obviously female, and hanging around the 184-188 mark. I eat low cal (definitely not intentional!! I try to eat before 7PM and my work doesn't always let me go grab a quick bite before I leave for my lunch break run. I mainly do cardio but I am trying to get into lifting) I'm burning about 800-1000 calories a day in exercise between 30 Day Shred and c25k and general walking, not to mention my FitBit.

Replies

  • ziegman49
    ziegman49 Posts: 28 Member
    You would be surprised. It is only an estimate but gives you an idea. Most nutrition labels are based on a average BMR, hence the 2000 mark. You may be higher or lower. This is a practices as a science.
  • FlannelMothman
    FlannelMothman Posts: 193 Member
    It both seems high, and low.

    I could stay in bed all day for two days a week (and I guess not eat?) and still lose a pound? That seems messed. I'd figure I'd lose more than a pound. On the other hand, doing absolutely nothing, I should burn less.
  • ziegman49
    ziegman49 Posts: 28 Member
    Ever lose weight when you are sick and not eating? Don't people starve to death? :)
  • BlueObsidian
    BlueObsidian Posts: 297 Member
    Your heart is beating 24 hours a day, pumping blood around your body. Your lungs are breathing 24 hours a day, taking in the oxygen you need to breath. Those things take energy, which is what calories measure.
  • It's not a completely accurate number but it does have a good base number. The amount of lean body mass opposed to fat mass etc cannot really be determined in the formula so the actual number can be higher or lower, but again, a good number to start with. It is tedious, but eating a certain number of calories a day for a week and checking your weight each week to see if your weight has gone up or down will show you how much calories you can take in :)
  • WinnerVictorious
    WinnerVictorious Posts: 4,733 Member
    You use energy no matter what you're doing, even when sleeping. The BMR Calculator will calculate your Basal Metabolic Rate (BMR); the number of calories you'd burn if you stayed in bed all day.
    (...)
    BMR is 1665.5.

    Seriously, I don't think is right. There's no way I'd burn over a thousand calories doing NOTHING. Seriously. That can't be accurate.
    I'm about 5'6", 25, obviously female, and hanging around the 184-188 mark. I eat low cal (definitely not intentional!! I try to eat before 7PM and my work doesn't always let me go grab a quick bite before I leave for my lunch break run. I mainly do cardio but I am trying to get into lifting) I'm burning about 800-1000 calories a day in exercise between 30 Day Shred and c25k and general walking, not to mention my FitBit.

    yes you do. how do you think your body maintains a constant body temperature? or digests your food? or fuels the muscles that you need to use to move your arms and legs? and a 101 other things in your body... all day, every day.

    now, i'm going to blow your mind even more... that BMR number above is ONLY the calorie burn if you slept all day in bed and never woke or got up. if you get up, brush your teeth, fix yourself coffee, walk to the mailbox to check the mail, and 101 other common little things you do all day, you have to multiply that by a number to account for those extra calories. if you're sedentary (work a desk job), then that multiplier is 1.2x. this means your true calorie burn for the day is right around 2000 calories.

    ...and this does not include specific cardio you do to lose weight, such as jogging or zumba or the elliptical.

    once you understand all of this and are comfortable determining your daily calorie needs, then all you need to do is log what you eat and make sure you maintain a deficit between "calories in" and "calories out" and you'll start losing weight.

    also, don't worry about when you eat. eat early, eat late... it doesn't matter. all that matters is how much.
  • cmriverside
    cmriverside Posts: 34,419 Member
    It both seems high, and low.

    I could stay in bed all day for two days a week (and I guess not eat?) and still lose a pound? That seems messed. I'd figure I'd lose more than a pound. On the other hand, doing absolutely nothing, I should burn less.

    I dont think you aer understanding the definition of BMR. Please do some reading on a medical site for more info.

    Here: this will help,

    http://www.myfitnesspal.com/topics/show/804485-in-place-of-a-road-map-2-0-revised-7-2-12
  • It probably is for a person with an average metabolism. But it is still only an estimate, since the calculator doesn't take into acct lean muscle vs. fat. To get anything more than an estimate you need to get it tested. A person's BMR is 5%-15% lower than their RMR. For me it was pretty far off. My BF is 32.9%, I'm 5'1 & 144.4 lbs. 51 yrs old. The tool here says my BMR is 1217, but my tested RMR is 1066, making my BMR somewhere between 906 & 1012.
  • jiggy66
    jiggy66 Posts: 52 Member
    MFP calculates my BMR at 2650. A month ago, I went to a weight loss doctor who connected me to some fancy machine and had me do a breathing test that calculated my BMR and guess what - my BMR is 2600. It's actually correct. I can't believe it either, it's crazy to think right? But it's pretty accurate.
  • Jaulen
    Jaulen Posts: 468 Member
    I have a BMF armband, and while I'm sleeping it says I burn about 1.1 calories a min.

    So if I slept all day and did nothing else, Imy body would use 1584 calories......or 1440 of you took off 10% for error in readings.

    Seems totally reasonable to me.
  • SmartAlec03211988
    SmartAlec03211988 Posts: 1,896 Member
    I have a BMF armband, and while I'm sleeping it says I burn about 1.1 calories a min.

    So if I slept all day and did nothing else, Imy body would use 1584 calories......or 1440 of you took off 10% for error in readings.

    Seems totally reasonable to me.
    Same here. Mine says ~1.15 cal/min. when I'm sleeping.

    Sounds accurate to me.