MFP has my BMR wrong - need some advice please

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sammybingo
sammybingo Posts: 10
in Health and Weight Loss
Hi All,

So I've been using MFP on and off for a year or so, and really like it - it helps me track what I do really well.

However, I'm a biology geek (animals though, not humans!) and am lucky enough to have access to a lab, where my BMR has been accurately calculated, several times, to be just over 1800. My BMI, which I know is a rubbish measurement, is 36.

I use a Fitbit, and my average actual daily burn of calories is 2400+.

I think what MFP tells me to aim for is actually wrong, way too low, and I'm a bit puzzled about where I should have my aim. Sometimes I accidentally eat way too little, well, I eat tons but it's all low cal, and I realise now that I should be increasing this to some level, as my weight loss has really slowed after shedding 6kg over the last 8 weeks or so.

I'd like to aim for around 0.5-1kg a week as a loss, and am aware that I need to up my eating - thankfully, friends keep buying me my best chocolates, so I guess I should start eating them! But I'm a touch unsure about where to put my goal. I don't want to accidentally go into this starvation mode, or be unhealthy, which I think I have been doing, I want to find a happy medium.

Can anyone be bothered to do a quick bit of 'what might work better' advice for me please?

Many thanks :)

Replies

  • SezxyStef
    SezxyStef Posts: 15,268 Member
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    depending on how much you have to lose would define your goals..not necessarily what you want to lose.

    If you have 75+ lbs to lose 2 lbs/week is ideal
    If you have 40-75 lbs to lose 1.5 lbs/week is ideal
    If you have 25-40 lbs to lose 1 lbs/week is ideal
    If you have 15 -25 lbs to lose 0.5 to 1.0 lbs/week is ideal
    If you have less than 15 lbs to lose 0.5 lbs/week is ideal

    1kg a week would mean you have over 100lbs to lose...do you?

    btw starvation mode is a myth...

    So basically enter you starting weight, goal weight, activity level (no exercise included) and weekly weight loss goal in and MFP will give you a calorie deficit to reach your goal without exercise.
  • DanaDark
    DanaDark Posts: 2,187 Member
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    Burning 2400 a day?

    -500 for 1 pound a week loss.
    -250 for 0.5 pound a week loss.

    So, eat between 1900 and 2150 then.
  • sammybingo
    sammybingo Posts: 10
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    Many thanks to both of you - I've got just over 40lb I'd like to shift, and 1.5lb a week sounds a healthy target to me.

    I'm also glad people are saying starvation mode is bs - I've long suspected that, and I've just done some more reading and I'm glad that's been confirmed (in this context, anyway!).
  • Mr_Knight
    Mr_Knight Posts: 9,532 Member
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    However, I'm a biology geek (animals though, not humans!) and am lucky enough to have access to a lab, where my BMR has been accurately calculated, several times, to be just over 1800. My BMI, which I know is a rubbish measurement, is 36.
    ...
    I use a Fitbit, and my average actual daily burn of calories is 2400+.

    It sounds like you have a lot to lose. If that is true, you can certainly go below 1800 safely, for an extended period of time, as long as you ensure adequate nutrient intake (micro and macro).
  • bwogilvie
    bwogilvie Posts: 2,130 Member
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    I use a Fitbit, and my average actual daily burn of calories is 2400+.

    When you say "actual," do you mean what your Fitbit estimates? Those estimates are not necessarily very accurate, depending on what you do when you're active (http://well.blogs.nytimes.com/2014/03/10/activity-trackers-dont-sense-everything/?_php=true&_type=blogs&_r=0). Short of calorimetry or doubly labeled water, it's difficult to get an accurate measurement of TDEE. If your calorie logging is accurate, though, you can calibrate your Fitbit's estimates by comparing its projected weight loss against your actual results.
    I think what MFP tells me to aim for is actually wrong, way too low, and I'm a bit puzzled about where I should have my aim.

    Out of curiosity, what did MFP tell you to aim for, and what activity level and weekly weight loss goal did you set for it?
  • sammybingo
    sammybingo Posts: 10
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    I use a Fitbit, and my average actual daily burn of calories is 2400+.

    When you say "actual," do you mean what your Fitbit estimates? Those estimates are not necessarily very accurate, depending on what you do when you're active
    I think what MFP tells me to aim for is actually wrong, way too low, and I'm a bit puzzled about where I should have my aim.

    Out of curiosity, what did MFP tell you to aim for, and what activity level and weekly weight loss goal did you set for it?

    My fitbit is very accurate at how much walking I do, and noting periods of activity vs inactivity, as the article you link to concludes. It does not notice when I do weights, crunches, cleaning etc. So, if anything, the 2400 is probably a bit less than what I actually do - my colleagues at work (academic nutritionists who study this sort of thing for a living, and publish their work - I kind of trust them ;) ) estimated my true output to be around 2500 a day before I even got my fitbit.

    I can't remember what MFP told me to aim for now, I could jiggle all the settings around again and look.. yeah, it's saying to lose 0.75kg/1.5lb a week I should have a net intake of 1320. It thinks my normal daily activity will have me burning 2,170 cal/day, which is a shortfall of at least a several hundred. Perhaps I am a bit more active than I thought when I start MFP, but I don't really have that active a job. I've reset it to 1650 net cals a day!

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