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PB Book Typo / Error: Help Please (Harris Benedict calculations seem flawed

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  • PB Book Typo / Error: Help Please (Harris Benedict calculations seem flawed

    Hi, first post, am getting everything ready for the diet and exercise primal style.

    BUT, there's some issue I encountered in the book.

    Mark writes, when it comes to determining you BMR and using the Harris Benedict formula:

    you have MULTIPLY your BMR times 0.55 to determine your "activity factor". 0.55 is for a person doing moderate exercises throughout the week. This is what I am doing.

    HOWEVER, I went online to calculate this stuff, and the same website that Mark refers you to go to ( has a DIFFERENT FORMULA:

    It says, instead of multiplying your BMR x 0.55 (for moderate exercise), it says to multiply your BMR by 1.55 (NOT 0.55, as Mark suggests in his book).

    I am confused here. What is the actual number? Anyone know?


  • #2
    i didnt notice that in the book. if your question is what calculation to use, its 1.55! for sure without a doubt thats the harris formula! 1.55 for moderate

    i went primal in feb 2010
    37% body fat
    38-40 waist

    1 year to the day
    7.8% body fat
    29 waist

    7% body fat
    29 waist


    • #3
      thanks. Maybe my Kindle version has the typo, but other versions don't. But yeah, I'm looking at it right now: 0.55. confused the hell of out me. The weird part, though, is that all the other calculations after this that are given for Ken Korg's "example diet" are in accordance with the 0.55 calculation.

      comparing my results to ken korg's are so different it seems wrong. Do my results seem strange, or are these normal? ::

      BMR: 1938 (23 years old, 5 ft, 9 in., 184 lbs, Male)
      Activity Factor (Harris Benedict): 1938 x 1.55 = 3003
      Average Daily Calorie Expenditure: 4941

      If my goal is to have a Calorie deficit of, let's just say, 941 (you choose your own number, right? I know the deficit is between 500 and 1000, so you can choose right?), then my Daily Average Intake should be about: 4,000?

      Those seem like a lot of calories, am I accurate with this?

      any input would be awesome


      • #4
        I see your goal is weight loss, but what are your numbers now? Are you obese? Just getting really lean?

        If you're new to paleo/primal, I'd start by NOT worrying about calories, but instead food quality. Take on the Whole30-Challenge.


        • #5
          Mark is saying to multiply by 0.55 and add that onto your BMR.

          The other web site is saying to just multiply by 1.55, and that's your final number, no adding involved.

          So they're both saying the same thing, and with your numbers, 3003 is your calculated expenditure.
          "mayness, you need to have a siggy line that says "Paleo Information Desk" or something!" -FMN <3

          I'm blogging again, at least a little bit.


          • #6
            .55 is if you're adding the result to your BMI, 1.55 is if you're using that as your final caloric expenditure. For example:

            BMI 1800 (making this up)
            Activity factor 1800*0.55 990
            Total caloric expenditure 1800+990 2790

            BMI 1800
            Total caloric expenditure 1800*1.55 2790

            This is due to a mathematical property (don't remember what it's called), A+(A*C) = A*(1+C)

            So taking your example with BMI of 1938:
            Total expenditure is 1938*1.55 = 3003.9