I think I broke physics

BigT555
BigT555 Posts: 2,067 Member
in Food and Nutrition
So bear with me here, I was just doing some brain thinking and realized something

if you eat 1 gram of pure fat, thats 9 calories. And to lose 1 lb you need to burn 3500 calories, or conversely to gain a lb you need to eat 3500 calories (above/below TDEE).

so 1 g of fat= 9 cals

9 cals divided by 3500 cals/lbs = 0.0025714285714286 lbs

0.0025714285714286 lbs times 453.592 g's per pound = 1.16637942857 g's

so 1 g of fat eaten = 1.166 g's gained? what happened to conservation of mass and energy?
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Replies

  • emily889
    emily889 Posts: 296 Member
    Ow..
  • miss_jessiejane
    miss_jessiejane Posts: 2,819 Member
    45647-Math-is-hard-IbvL.jpeg
  • darkguardian419
    darkguardian419 Posts: 1,302 Member
    Yep... this is why I'm an Engineering Technician, not an Engineer. Same pay, less math.
  • scarletrayne19
    scarletrayne19 Posts: 35 Member
    As a scientist (who nearly failed physics) all I can say is when something is within two tenths like that I just shrug, chalk it up to some math error on somebody's part and say "close enough."
  • jackpotclown
    jackpotclown Posts: 3,275 Member
    giphy.gif
    \m/
  • FlowerFairy493
    FlowerFairy493 Posts: 182
    Wait what??? Lol
  • JoshLikesBeer
    JoshLikesBeer Posts: 88 Member
    Rounding. Your math assumes that fat is precisely 9.0 calories per grams. It's actually slightly higher. Also, the number is different for different fats, and it can range from like 8.7 to 9.5, depending on how long the chains are and how saturated they are.
  • MagnumBurrito
    MagnumBurrito Posts: 1,070 Member
    3500cal / 9 = 388.88 grams of fat / lb

    where's the 453.592 g's / lb coming from?
  • The_Enginerd
    The_Enginerd Posts: 3,982 Member
    Adipose tissue (body fat) is not made of purely fat (pure lipids, what is counted in dietary fat). Human fat tissue contains about 87% lipids.

    edit: Accounting for that, 9 calories/gram*453 grams/lb*0.87 =3547.
  • JoshLikesBeer
    JoshLikesBeer Posts: 88 Member
    Rounding. Your math assumes that fat is precisely 9.0 calories per grams. It's actually slightly higher. Also, the number is different for different fats, and it can range from like 8.7 to 9.5, depending on how long the chains are and how saturated they are.

    Edited to add, run your calculations backwards and solve for calories per gram, and you'll have a more precise number to work with.
  • wheird
    wheird Posts: 7,963 Member
    Rounding. Your math assumes that fat is precisely 9.0 calories per grams. It's actually slightly higher. Also, the number is different for different fats, and it can range from like 8.7 to 9.5, depending on how long the chains are and how saturated they are.

    This.
  • Hornsby
    Hornsby Posts: 10,322 Member
    3500 is an estimate.
    9 cals per gram is an estimate.

    Voila!
  • brianpperkins
    brianpperkins Posts: 6,124 Member
    9 calories per gram of fat is an approximation which makes it impossible to know just how far off your calculations are. Physics is fine (until CERN finally fires up the LHC again next year and creates a singularity that restarts the universe at another bang).
  • marissanik
    marissanik Posts: 344 Member
    I'm just unsure of what you're trying to calculate here?? What.
  • KseRz
    KseRz Posts: 980 Member
    So bear with me here, I was just doing some brain thinking and realized something

    if you eat 1 gram of pure fat, thats 9 calories. And to lose 1 lb you need to burn 3500 calories, or conversely to gain a lb you need to eat 3500 calories (above/below TDEE).

    so 1 g of fat= 9 cals

    9 cals divided by 3500 cals/lbs = 0.0025714285714286 lbs

    0.0025714285714286 lbs times 453.592 g's per pound = 1.16637942857 g's

    so 1 g of fat eaten = 1.166 g's gained? what happened to conservation of mass and energy?

    http://www.myfitnesspal.com/topics/show/1376778-recomp-math

    ??

    ETA: OPs Quote from link above.

    So one lb of fat is as much as one lb of muscle its all mass right but that is where the mistake comes in. So let me go over the numbers

    1 lb = 453.6g
    1g of fat=9 cal
    1g of protein= 4 cal
    1g of water = 0 cal

    This is stuff we all know, we also know that one lb of fat =3500 cal but 453.6g x 9cal= 4082cal. So how can this be right the numbers just don't add up right. The problem is fat is not all "fat", fat is made up of cells, that are mostly made up of water, but they hold a large amount of oil in them. So a lb of fat is made up of about 86% oil so that would about 390g of fat and 63g of water. Ok so more math now.

    1lb=453g
    390g oil x 9= 3510
    63g water x0=0
    390g+63g= 453g=1 lb
  • michikade
    michikade Posts: 313 Member
    Technically speaking:

    Lard - pure fat - is 905 calories for 100 grams - and even that figure is slightly rounded - so that fraction of a calorie per gram accounts for the variance. :)
  • BigT555
    BigT555 Posts: 2,067 Member
    3500cal / 9 = 388.88 grams of fat / lb

    where's the 453.592 g's / lb coming from?
    453.592 is the conversion from pounds to grams. what you calculated is the inverse of what i calculated in my first equation;

    3500cals/ lb divided by 9 cals = 388.88 lbs^-1. gotta watch those units
  • SuperVixen2B
    SuperVixen2B Posts: 218 Member
    45647-Math-is-hard-IbvL.jpeg

    Hahahahahaha! :laugh:
  • MagnumBurrito
    MagnumBurrito Posts: 1,070 Member
    grams / lb are off - 388.888 for fat
  • UsedToBeHusky
    UsedToBeHusky Posts: 15,228 Member
    Um...

    You need to show your work. What in the hell are you talking about?

    1241025633_motivational_poster_time_paradox.gif
  • jasonmh630
    jasonmh630 Posts: 2,850 Member
    c82a791547aa439fd76b9fdee32c0483.jpg
  • GretchenReine
    GretchenReine Posts: 1,374 Member
    Gary-Coleman-wtf.gif
  • runningagainstmyself
    runningagainstmyself Posts: 616 Member
    giphy.gif
    \m/

    This. <3 \m/
  • SunofaBeach14
    SunofaBeach14 Posts: 4,899 Member
    Estimating and TEF?
  • Catchphrase33
    Catchphrase33 Posts: 40 Member
    The answer is Orange because my cat likes to dance.
  • BigT555
    BigT555 Posts: 2,067 Member
    lol to everyone asking what i was calculating; its a conversion of the 9 calories contained in a gram of fat to the 3500 calories contained in a pound. basically if you go full circle you get 1 gram of fat eaten yeilding a fat gain of 1.166 g's

    im going to assume its some sort of rounding error, but most numbers i got for calories in a gram of fat had a few zeros after the decimal place inferring a higher accuracy than just to one integer
  • jasonmh630
    jasonmh630 Posts: 2,850 Member
    The answer is Orange because my cat likes to dance.

    No, the answer is blankets because pigeons don't like spaghetti.
  • FaylinaMeir
    FaylinaMeir Posts: 661 Member
    cat-meme-i-cannot-brain-today-dumb.jpg
  • BigT555
    BigT555 Posts: 2,067 Member
    Um...

    You need to show your work. What in the hell are you talking about?

    1241025633_motivational_poster_time_paradox.gif
    i totally showed my math!

    though i dont even know what the hell im talking about anymore
  • Mr_Knight
    Mr_Knight Posts: 9,532 Member
    ...3500 cals/lbs ....

    That number is an approximation. Any number ending in double zeros is likely to be.
    9 calories...

    So is that one.

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