Confused about BMR, TDEE, and Deficit? How many calories you

baisleac
baisleac Posts: 2,019 Member
edited September 2024 in Health and Weight Loss
If you're not simply trusting MFP's numbers, you need to know this.

BMR - Basal Metabolic Rate - "The amount of energy utilized per unit time under conditions of basal metabolism; expressed as calories per square meter of body surface or per kilogram of body weight per hour." ~FreeDictionary

Your BMR is the number of calories your body needs to sustain your life in a coma; not your every day life, a coma.

You can determine a rough estimate of your BMR on any web based BMR calculator. For a better estimate (without resorting to expensive tests), use your body fat percentage to determine your lean body mass (Google "Lean Body Mass Calculator") then use that number to determine your BMR. BMR = 370 + (21.6 X lean body mass in kg).


TDEE - Total Daily Energy Expenditure - "how many calories you burn in a day, including all activities" ~Rockwell Fitness

Your TDEE number is the number of calories you burn living your life every day. THIS is the number your weight loss deficit needs to come from.


To determine your TDEE multiply your BMR by the appropriate number below:

If you are sedentary (little or no exercise) : 1.2

If you are lightly active (light exercise/sports 1-3 days/week) : 1.375

If you are moderatetely active (moderate exercise/sports 3-5 days/week): 1.55

If you are very active (hard exercise/sports 6-7 days a week): 1.725

If you are extra active (very hard exercise/sports & physical job or 2x training): 1.9


Subtract your calorie deficit from this number, your TDEE; remembering that if you exercise, those exercise calories need to be recovered to maintain your calculated deficit.

Replies

  • baisleac
    baisleac Posts: 2,019 Member
    one bump
  • sashaverlene
    sashaverlene Posts: 123 Member
    My BMR is 1600... my TDEE is 2480. So I should eat 1600 calories? This confused me! lol
  • baisleac
    baisleac Posts: 2,019 Member
    My BMR is 1600... my TDEE is 2480. So I should eat 1600 calories? This confused me! lol

    BMR is used to calculate your TDEE. Your TDEE is the number you take your deficit from. To lose 1 lb per week, subtract 500 kcal/day (1980). To lose 2 lb per week, subtract 1000 kcal/day (1480).

    On the other hand, many nutritionists recommend not going below 80% of your TDEE, which would be 1984 calories per day. You'll note this is approximately the same as 1 lb. per week, in your case.
  • baisleac
    baisleac Posts: 2,019 Member
    Bumping again because I'm see more folks confusing BMR and TDEE again.

    They are not the same thing.
  • SaraTonin
    SaraTonin Posts: 551 Member
    Bump. Great informative post!!
  • BflSaberfan
    BflSaberfan Posts: 1,272
    Question, if the TDEE is taking into account your exercise level, you should still eat back your exercise calories?

    According to MFP my BMR is 1414 (5'2 139lbs sedentary desk job) but I do the Insanity workout 6 times a week, so if I use your calculation below 1414 * 1.725 = 2439 - this would be my maintenance calories. Because I want to lose weight I could subtract 500 for 1 lb a week leaving me with 1939.

    On top of that I should eat back my exercise calories?
  • robertf57
    robertf57 Posts: 560 Member
    Make sure you recognize that this calculator is in kg and not lbs......
  • baisleac
    baisleac Posts: 2,019 Member
    estion, if the TDEE is taking into account your exercise level, you should still eat back your exercise calories?

    Please note that I referenced people who are not simply trusting MFPs numbers.

    However, if you exercise regularly, you WILL burn more calories sitting at your desk than your evil twin sitting next to you that doesn't exercise. Each person needs to find the balance of fueling that extra energy consumption.

    If, on the other hand, you are trusting MFPs numbers then, YES, absolutely eat your exercise calories.
  • SHBoss1673
    SHBoss1673 Posts: 7,161 Member
    This is why I don't use TDEE when explaining MFP, technically it's right, but it can confuse some.

    I use the term maintenance calories, which is basically how many calories you need to maintain your current weight NOT INCLUDING extra exercise.

    Put it this way, if you were to include insanity with your activity level, then instead of being sedentary, you'd be very active, you can do this, but the problem is, people tend to forget about this, and if you ever stopped doing insanity, you'd be WAY over your estimated maintenance. Plus on the day you're not doing insanity, you're way over estimating.

    it's just much easier to calculate your daily activity level without the extra exercise, and to add that in at the time you perform it, this way you're not only being accurate, you're also forcing yourself to recognize exercise for what it is, and not lumping it all into a single, very generic, grouping.
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