MFP wants me to eat below my BMR

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thrillho3
thrillho3 Posts: 50 Member
in Health and Weight Loss
The BMR calc on MFP tells me that my BMR (female, 31, 5'5", 198) is 1,617 cal/day. Yet in order for me to lose 1lb/week, MFP suggests I eat 1,500 cal/day. Isn't this dangerous? I work a sedentary job but I also do circuit training 4x/week.

I've read that you shouldn't eat below your BMR, so I'm just wondering... thanks.

Replies

  • Mr_Knight
    Mr_Knight Posts: 9,532 Member
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    The BMR calc on MFP tells me that my BMR (female, 31, 5'5", 198) is 1,617 cal/day.

    That's about 200 calories/day too high. The calculator is not accounting for your body composition - not all pounds are metabolically equal.
  • thrillho3
    thrillho3 Posts: 50 Member
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    Right. So I did the skin fold caliper thing and it told me I had 38% BF. How does this factor in?
  • omma_to_3
    omma_to_3 Posts: 3,265 Member
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    People on MFP like to say it's bad to eat below your BMR, but I disagree (with some caveats). I NET below my BMR, and have for 3 years now. And I've had my RMR tested multiple times and it's always 10% above the average so it's certainly not affecting my BMR. If you're eating back your workout calories, you will be just fine.
  • ottermotorcycle
    ottermotorcycle Posts: 654 Member
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    Right. So I did the skin fold caliper thing and it told me I had 38% BF. How does this factor in?

    If you have an accurate measure of your body fat percentage, then it's best to use a BMR calculator that takes that into account, as this will be the most accurate.

    One method is to figure out your lean body mass (by subtracting your body fat from your total weight) and multiply that by 13.8. (The Sterling-Pasmore equation according to bodybuilding.com)
    So for you that's 100-38 = 62% lean body mass. 62% of 198 is 122.76lbs. By that calculation, your BMR is 1694. Which... is actually higher than the number you had before.

    I would shoot for 1700 net calories/day and see if you lose weight on it. That should also equal out to your TDEE - 20%, which is a method a lot of people use. You can always lower your calories if it's not working for you.
  • michael300891
    michael300891 Posts: 275
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    BMR does not include activity levels. BMR = what you would burn in a coma. BMR + energy expenditure from exercise, non exercise activity time, and thermogenic effect of feeding all add up to put a few hundred extra calories on the total.

    Take away 500 kcals and you can see how your aiming to net under your BMR. Its not a problem in any way.
  • thrillho3
    thrillho3 Posts: 50 Member
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    Right. So I did the skin fold caliper thing and it told me I had 38% BF. How does this factor in?

    If you have an accurate measure of your body fat percentage, then it's best to use a BMR calculator that takes that into account, as this will be the most accurate.

    One method is to figure out your lean body mass (by subtracting your body fat from your total weight) and multiply that by 13.8. (The Sterling-Pasmore equation according to bodybuilding.com)
    So for you that's 100-38 = 62% lean body mass. 62% of 198 is 122.76lbs. By that calculation, your BMR is 1694. Which... is actually higher than the number you had before.

    I would shoot for 1700 net calories/day and see if you lose weight on it. That should also equal out to your TDEE - 20%, which is a method a lot of people use. You can always lower your calories if it's not working for you.

    Thanks!

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