BMR vs. TDEE: What MFP Is Telling You

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13

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  • BdaGolfer
    BdaGolfer Posts: 16
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    Bump, and looking for clarification for myself as well.

    My BMR (based on 3 different methods) is around 1,900.
    My activity factor is around 1.2 (desk job) so basic daily energy is 2,280
    Exercise (P90X) adds around 820 on average, so TDEE is 3,100 - correct?

    So, to maintain a small deficit I should eat in the 2,800 range, as any less and I am below my BMR? Essentially, my minimum should be ~1,900 + (net) exercise calories? I'm confused.....

    Alan

    Your BMR is 1,900.
    Your TDEE WITHOUT exercise is 2,280. WITH exercise it's 3100. So you should start around 2,600 and work your way down as you need to, remaining above 1900.

    Thanks for the reply, but this is why I'm confused. If I eat 2,600, and burn 851 (as I did this morning) that nets out at 1,749 - does the net number matter, as long as I eat above the BMR i.e. eat 2,600 and burn 800+? Or should the net be over the 1,900?

    Thanks,

    Alan
  • ivykivy
    ivykivy Posts: 2,970 Member
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    Bump!:wink:
  • Magenta15
    Magenta15 Posts: 850 Member
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    bumping for self :)
  • stormieweather
    stormieweather Posts: 2,549 Member
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    Bump. Had my RMR (ie: BMR) tested professionally and it's 1800. Add my daily living at about another 700 and my TDEE is 2500 +/-. No wonder eating 1200-1500 calories a day hasn't been working. My body isn't getting enough fuel.
  • carpediem13
    carpediem13 Posts: 41 Member
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    Bump. Great information I was confused about MFP's calculations and was just trusting them but I like understanding much more!
  • cmriverside
    cmriverside Posts: 34,104 Member
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    I'm bumping this because I think it keeps getting lost.

    BUT!

    I don't think songbyrd is around the boards much these days, look at her profile...she's deep into her PhD work. So, if anyone asks a question, she may or may not answer you.
  • astridfeline
    astridfeline Posts: 1,200 Member
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    BUMP :smile:
  • astridfeline
    astridfeline Posts: 1,200 Member
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    bump
  • lotusfromthemud
    lotusfromthemud Posts: 5,335 Member
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    bump!
  • WonderNoodle
    WonderNoodle Posts: 549
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    bookmarking :drinker:
  • Azdak
    Azdak Posts: 8,281 Member
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    The BMR equation used on this site (I forget the name) has been listed as one of the more accurate in review articles I have read. In case it matches the BMR reading I got from a metabolic cart almost exactly. (so I can't use "low metabolism" as an excuse ;-)
  • daybyday
    daybyday Posts: 537 Member
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    Bump
  • lotusfromthemud
    lotusfromthemud Posts: 5,335 Member
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    BUMP!:noway:
  • cmriverside
    cmriverside Posts: 34,104 Member
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    bump, though I think songbyrd has left the building.....:sad:
  • cmriverside
    cmriverside Posts: 34,104 Member
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    please let them read it.....
  • cmriverside
    cmriverside Posts: 34,104 Member
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    Hi, Song. Once more for old time's sake.
  • MisterDubs303
    MisterDubs303 Posts: 1,216 Member
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    Here's a tool I like. They separate the estimated base (BMR) from the actual base.
    http://www.webcalcsolutions.com/Health-Calculators/Full-Body-Analysis.asp?AcctNum=3
  • geecee77
    geecee77 Posts: 149 Member
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    Bump
  • songbyrdsweet
    songbyrdsweet Posts: 5,691 Member
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    Oh man, this is old! Haha :) I can't believe I've been here for so long!
  • ShrinkRapt451
    ShrinkRapt451 Posts: 447 Member
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    Ok, again--the BMR tool is not what MFP is basing your calories upon. Look on your goals page, you'll see a number on the right hand side of the screen that is what MFP calculates to be what SBS is calling the TDEE

    I agree, and I changed it manually, because it doesn't do this for us. So therefore the BMR tool in here is accurate or as accurate as they get. Not everone knows that the two parts of the program aren't working together, and therefore your calories must be adjusted manually. Because of all the talk of not going below your BMR in here, people beleive that the program automatically sets this for them.

    That was all I was saying.

    When you use the actual BMR Calculator under Tools, that's just BMR. It's not as accurate as others because it doesn't ask for body fat %, so you should look around for one that does.

    When you set your Goals and MFP asks for your Activity Level, that is your TDEE. However, when MFP subtracts the calories to create a deficit, it may have you eat less than your BMR--maybe by quite a lot if you set a goal that is too high (like 2lbs/wk). This is why it's very important to start of with a lower goal, exercise to regain calories, and pay attention to both figures. If you start off too low, there's nowhere to go once you plateau. You're right that MFP doesn't use those two figures together, so we need to pay attention to what we're doing.

    What I think folks should understand is that when MFP asks for your activity level, it calculates your TDEE (without exercise). If you then ask it for a 2 lbs/week loss goal, it will subtract 1000 calories a day from that TDEE number. Which may well be below your BMR.

    So let's say that you tell MFP that you're sedentary and want a 2 lb/week loss. You may be told to eat 1200 calories. Let's say you do that. And sometimes come in short, because you want to see "and was under his/her calorie goal" show up in your news feed every day. (We like that "remaining" number to be green, not red.)

    Say you start exercising. If you do NOT eat back your exercise calories, you are starting with a 1000 calorie deficit from your food intake, and then ADDING a further deficit from exercise. Your body may well panic. Bye-bye, weight loss.

    Say you start exercising and you DO eat back your exercise calories. You stay at a 1000 calorie deficit because of the initial deficit calculated by MFP. So, theoretically, you should lose 2 lbs/week.

    You may not, for a variety of reasons, actually lose 2 lbs. But the numbers work out that way. And lemme tell ya, if you actually eat your BMR calories, you'll feel a heck of a lot better.

    Warning: if you've been eating way under your BMR calories for a while, you may gain for a bit when you first start eating more. If it keeps up for more than a month, then re-evaluate. But you should start losing again after a few weeks.

    Also: if you lose enough weight, MFP will suggest you re-do your goals. If you don't, then it won't change your calorie goal, even though your BMR has changed. If you reset your goals, however, it'll recalculate using your new BMR.

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