March 20, 2008

  • And look....another entry

    about nutrition/weight loss! We can all see what is on my brain of late.


     


    Okay, so you know you should lose weight. So how do you do it? You need to consume 3,500 calories less than you use to lose one pound of body weight. For a comfortable weight loss each week - one pound - you should consume 500 calories less each day than your body requires. For two pounds, consume 1000 calories less. Or I suppose you could burn 500 more or 1000 more. But I get side-tracked.


    But, you may ask, how do I know what my body requires?
    There are all kinds of estimates and you can calculate or get tested for your Basal Metabolic Rate (BMR) or your Resting Metabolic Rate (RMR) (which is just how many calories you burn everyday just to breathe). To take into account movement and all that jazz, you can calculate your estimated energy requirement (EER).


    And now we will calculate MY EER. 'Cuz math is rockin'!


    Please do note that the equation for MEN is different (because men suck and get more calories just for having a penis and more lean tissue) and will be included at the end!


    Assuming that you are 19 years or older, you need your weight (in kg) and your height (in m). Damn metric system.


    So.
    We will convert.


    I am 171.6lbs according to my home scale.
    171.6/2.2 = 78kg


    I am 61.5 inches, or so I was last time I measured and I doubt that I magically grew.
    61.5/39.37 = 1.56m


    This is the equation (and it is a LOT of numbers):


    EER = [354-(6.91*age)] + PA * [(9.36*weight) + (726*height)]


    What is the PA you may ask?
    This is your Physical activity factor and can be obtained from a nifty little chart that I don't have so I will sum up.
    First, determine if you are sedentary (typical daily living activities), low active (30-60 additional minutes of moderate activity), active (at least 60 additional minutes of moderate activity) or very active (at least 60 additional minutes of moderate activity AND another 60 minutes of vigorous or 120 minutes of moderate activity). Now, if you're sedentary, men and women get a PA of 1.0 for that. Men get a 1.11 for low active (women are a 1.12). Active men get a 1.25 and women are 1.27. For very active, women are 1.45 and men are 1.48.


    Moderate activity is equivalent to walking at 3 to 4.5mph.


    I am a low active woman and my PA is 1.12.


    And now we plug and chug (but I'll walk through it slowly because I am sometimes math-slow and required help to do it the first time myself).


    EER = [354-(6.91*28] + 1.12 *[(9.36*78) + (726*1.56)]


    First do your parentheses!


    EER = [354-(193.48)] + 1.12 * [(730.08) + (1132.56)]


    Now do your brackets!


    EER = [160.52] + 1.12 * [1862.64]


    Now, multiply before you add!


    EER = 2246.68


    Now, most people will be within 1 standard deviation or +/-200 calories but nearly all people (2 standard deviations) will be +/-400 calories.


    So....err on the side of caution and my EER is.....(with rounding)....1850 calories to 2650 calories.


    And I consume approximately 1500 calories with my WW diet.
    My calories deficit per day is 350 to 1150 (we'll go with the calculated EER to make my mind less crazy) and say that I am consuming about 750 calories per day less than I burn. That comes out to about 1.5lbs per week.


    Male equation is as follows:
    EER = [662-(9.53*age)] + PA * [(15.91*weight) + (539.6*height)]


    I have no idea why this fascinates me so much.

Comments (6)

  • i think you should get some kind of award for just knowing this. wowza.

  • This fascinates me too, and as I am currently having insomnia, I calculated my numbers! For my current weight, my EER=2552. I also calculated my EER based on my (eventual) goal weight to see what I would require to MAINTAIN that weight and my EER (for goal weight)=2216. I also used 1.12 for my activity factor, given how much (and how fast) I walk at work. I am not convinced that these numbers are accurate. I can tell you that if I consumed 2200 calories/day right now at my current weight , I would most likely GAIN. I don't know if this is a flaw in metabolism, as I have probably been BLESSED with a very SLOW metabolism, but these numbers don't particularly make sense to me. I have done a lot of education on diet with my patients and even for maintaining weight at a sedentary level, we aren't recommending this many calories. Now I'm going to be forced to do more reseach on daily calorie requirements.

    P.S. I love math!

  • I love this stuff, too. Not the math part, because simple subtraction has me running for the hills. But my days fall into 3 different activity categories, and I know my BMR for each. I re-check it every couple years because it changes as you age. For example, today I'm sedentary (flu), so I have to stick to 1260 calories to maintain my weight.

  • @DeliaD - Do you find that having three different BMRs helps you maintain weight? I'm only just now learning and understanding all of this information and I want to know if it actually does work for someone in the real world!

  • @Kellybones - Absolutely!! I calculated one BMR for days I do nothing, like today, which is driving me OUT OF MY MIND.... sorry. ahem.

    I have a mid-range BMR for days I do a normal workout, like run 4 miles or lift weights.

    I use a third BMR for either 1) days I do a training run of 7 or more miles or 2) Tuesdays, when I do a normal workout and spend three hours doing extremely active work at the shelter.

    I've been following my BMR for over 20 years (and sadly watching my allotted # of calories plummet) but I've always easily maintained a wt of 110-115. I count calories and that's all. It's just become a habit after all this time.

  • By the way, that weight looks like a really low number. I should clarify that I'm only 5'2"!  :)

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