Is my math/theory correct? Please, someone to double-check my work... Math nerds needed!

marathon_44
marathon_44 Posts: 62 Member
in Health and Weight Loss
I've been wondering how my actual results compares with MFP's predicted calculations. I haven't been eating all my exercise calories back, due to uncertainty about their accuracy, but according to my math, it seems like I needn't have worried about that.

Over the last 30 days, I have lost 11 pounds. (I was about a month into healthy living at that point, so this figure shouldn't be too skewed by initial glycogen depletion/water weight loss).

My goal was 2 pounds a week, with 1200 cals per day assigned by MFP as goal. Therefore, if everything about my logging and exercise was accurate, I should have lost 8.57 pounds over those 30 days.

First, I took what MFP told me I should have eaten over that 30 days. (36000 cals.)
Then subtracted the last 30 days of my combined net calories. (29,125 cals.)

36000 minus 29,125 equals 6875 cals.

6875 calories works out to roughly 2 pounds (I'm rounding here)
8.57 predicted loss plus 2 pounds additional loss = 10.57
10.57 is pretty darn close to the 11 pounds of my actual loss.

Therefore, I think I'm pretty safe in believing that I can now fearlessly eat all of my exercise calories? Right?

Is my math off? Am I not thinking about this correctly? Please let me know!

Replies

  • lemurcat12
    lemurcat12 Posts: 30,886 Member
    The math looks right, and yes, it looks like you can safely eat all your exercise calories, which is excellent.

    You can also use those numbers to figure out your TDEE (your maintenance number with your current level of exercise). It appears to be about 2250. ((3500x11)+29,125)/30 That means that so long as you stay below 2250 (at your current weight, anyway), you are below maintenance.
  • greenhumanclay
    greenhumanclay Posts: 402 Member
    I agree your math looks accurate but making sure you are fueling your body properly. You can also find out what your BMR and TDEE ( Total daily energy expenditure) to get an accurate amount of the calories you should be consuming based off your training. http://iifym.com/tdee-calculator/
  • marathon_44
    marathon_44 Posts: 62 Member
    Thanks @lemurcat12!

    Your TDEE calculation looks good on paper, but it is very different from my calculations. And I can't figure out the discrepancy.

    I also totaled up the actual calories that I ate over that same period (not the net calories). This totals 53,434 (I checked this 3 times, so positive it is accurate). Therefore, I consumed on average 1,781 calories per day, while losing 11 pounds. If I then add in the calories that reflect the 11 pounds I lost (38500), that totals 91,934. This would average out to over 3,050 calories per day for my maintenance currently. Now, I am VERY active with good muscle mass, but that just blows my mind a little bit. What's wrong with this picture?
  • lemurcat12
    lemurcat12 Posts: 30,886 Member
    Oh, I didn't catch that it was net calories.

    If you ate 53430 gross, I agree the TDEE is about 3050.

    Makes sense if you lost over 2 lb/week (nearly a 1300 deficit) at 1781.

    You must be really active (as your profile suggests).

    I'm really impressed that you could maintain all that activity on such a deficit (I have found that I struggle to train really hard and keep much of a deficit), but I'd probably raise that up some -- either by eating back all exercise (as you said) or perhaps going to a milder deficit also or just doing TDEE-20% (or anything over 2000 if jumping up that high freaks you out, which I can understand).
  • Tedebearduff
    Tedebearduff Posts: 1,155 Member
    marathon_44 wrote: »
    I've been wondering how my actual results compares with MFP's predicted calculations. I haven't been eating all my exercise calories back, due to uncertainty about their accuracy, but according to my math, it seems like I needn't have worried about that.

    Over the last 30 days, I have lost 11 pounds. (I was about a month into healthy living at that point, so this figure shouldn't be too skewed by initial glycogen depletion/water weight loss).

    My goal was 2 pounds a week, with 1200 cals per day assigned by MFP as goal. Therefore, if everything about my logging and exercise was accurate, I should have lost 8.57 pounds over those 30 days.

    First, I took what MFP told me I should have eaten over that 30 days. (36000 cals.)
    Then subtracted the last 30 days of my combined net calories. (29,125 cals.)

    36000 minus 29,125 equals 6875 cals.

    6875 calories works out to roughly 2 pounds (I'm rounding here)
    8.57 predicted loss plus 2 pounds additional loss = 10.57
    10.57 is pretty darn close to the 11 pounds of my actual loss.

    Therefore, I think I'm pretty safe in believing that I can now fearlessly eat all of my exercise calories? Right?

    Is my math off? Am I not thinking about this correctly? Please let me know!

    How much of the weight loss was water?
    How much of your weight loss was muscle?
    How much was fat?
    What's the overall percentage??? let's see a pie chart!!!!!

    You can't gauge all this stuff my friend don't overthink everything you'll drive yourself nuts. If you want to eat all your calories back, eat them. If you stop losing well you know what you have to change then don't we ;)

  • marathon_44
    marathon_44 Posts: 62 Member
    Yes, that's exactly why I asked this question now. I've felt that my energy levels on my workout days didn't suffer that much as long as I didn't drop below 1700-1800 cals of very nutritious food. I've been PR'ing on all my heavy lifts lately, so I'm not overly concerned that my deficit has been too severe. I'm mostly curious as to how much I would totally rock my workouts with more calories. I'm definitely going to eat back ALL my exercise calories now. Thanks for your help!

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