Strange Weight Loss issue, need outside advice

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Replies

  • wraith1375
    wraith1375 Posts: 7
    Interesting. How do you calculate Lean Body Mass?
  • wraith1375
    wraith1375 Posts: 7
    using the wikipedia formula and converting everything to metric, I calculated out a RMR of 1783. Does that sound reasonable?
  • TrainingWithTonya
    TrainingWithTonya Posts: 1,741 Member
    Interesting. How do you calculate Lean Body Mass?

    Body weight x body fat % = Body fat mass

    Body weight - body fat mass = Lean body mass

    Also, these formulas all use kilograms of body weight or lean mass, not pounds. So for any of the calculations, divide weight in pounds by 2.2 to get kilograms.

    Example:

    220 pound person, 25% body fat, Workout burning 1000 Calories

    220 / 2.2 = 100 kg body weight
    100 x 0.25 = 25 kg body fat mass
    100 - 25 = 75 kg lean body mass

    RMR = 500 + (22 * 75)
    RMR = 500 + 1650
    RMR = 2150 Calories per day (not counting exercise)
    TDEE = 2150 + 1000
    TDEE = 3150 Calories per day
    Eat no less than 80% of TDEE = 3150 * 0.8 = 2520 MINIMUM Calorie Intake
  • wraith1375
    wraith1375 Posts: 7
    I guess the hardest part is how do you determine body fat %? You usually need to use a water displacement method don't you?
  • TrainingWithTonya
    TrainingWithTonya Posts: 1,741 Member
    I guess the hardest part is how do you determine body fat %? You usually need to use a water displacement method don't you?

    Hydrostatic weighing is one of the most accurate ways to measure it, but you can do a general estimate without anything but a tape measure if that is all you have. Here is a link to an old blog post I did with the formulas for estimating body fat.

    http://www.myfitnesspal.com/blog/TrainingWithTonya/view/determining-body-fat-104431

    While measurement formulas aren't the most accurate, they generally only have an error rate of 5%, calipers are 4%, and bio-electrical impedance 3% if they are all done properly.

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