Muscle, fat, density, weight, mass...oh my!

As a mechanical engineer, I find it upsetting the lack of understanding in basic scientific principles on the forums. I know people are just going to say "get over it" or "what's the big deal?" However, if people do not understand basic science then the perpetuation of fads, misinformation and outright lies in the fitness industry will continue. As an example, one concept that comes up a lot is the difference in the density of fat and muscle.

It usually goes something like this: Someone says "muscle weighs more than fat." Another person points out this is wrong because "a pound equals a pound." This person goes on the explain that "muscle is less dense than fat." Then the arguments start about nitpicking, context, etc. Underlying all the bashing and arguing is the unfortunate reality that both "sides" usually lack a complete understanding of basic physics.

Let's break down some of these statements:

"Muscle weighs more than fat" - This statement is more incomplete than inaccurate. It's incomplete because there is no frame of reference stated. A more complete statement would be "At sea level on Earth, an equal amount of volume of muscle weighs more than an equal amount of volume of fat at the same pressure and temperature."

"Muscle is more dense (sic) than fat" - Another incomplete statement. Again, there is no frame of reference. A better statement would be: "At the same pressure and temperature, muscle is denser than fat."

"A pound equals a pound" - This one irks me because it demonstrates the root cause of the misunderstanding of the general topic. Again, it's a frame of reference problem. Unfortunately, in the English system of units, "pound" is used interchangeably between weight and mass suggesting that weight and mass is the same thing. This is a false. In the scientific and engineering fields we distinguish between mass and weight by using either lbm or lbf, respectively. One pound-mass (lbm) is a unit that measures the amount of matter in a given object. It is always the same no matter where you are. So a true statement would be "1 lbm equals 1 lbm." (There is a disclaimer here because some of these rules break down in the quantum world, but I will admit myself that I do not understand a lot of that crazy stuff). One pound-force (lbf) is a unit that measures the amount of force gravity is exerting on a mass. A true statement would be "at sea level on Earth, 1 pound-force of muscle weighs the same as 1 pound-force of fat."

Again, my goal here is not to bash people, nitpick, or try to be all pretentious. I just want people to start understanding BASIC science! If more people understand science, the lies, misinformation and deceit the diet and fitness industry tries to use on us will not work as much and we can all start having a healthier relationship with food and exercise.

I apologize in advance for what is to come next, but it needed to be said…..

Let the games begin!
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Replies

  • BigT555
    BigT555 Posts: 2,067 Member
    or we could just let simple slips in proper language slide. nobody seems to b*tch when someone says "helium is lighter than air"
  • gotolam
    gotolam Posts: 262 Member


    I apologize in advance for what is to come next, but it needed to be said…..

    No, it really didn't.
  • rjmudlax13
    rjmudlax13 Posts: 900 Member
    or we could just let simple slips in proper language slide. nobody seems to b*tch when someone says "helium is lighter than air"

    You missed my point.

    Why the hell do I even bother. We are doomed as a species anyway.

    You're right! I'm just here to *****. You got it!

    I'm just going to keep my mouth shut and let stupidity perpetuate itself.
  • rjmudlax13
    rjmudlax13 Posts: 900 Member


    I apologize in advance for what is to come next, but it needed to be said…..

    No, it really didn't.

    Unfortunately, you're attitude is part of the problem.

    ETA: Grammar fail. I suck at life I guess. Really hope someone points that out as a way to disqualify me.
  • ashleydawndill
    ashleydawndill Posts: 242 Member
    I for one think it's nice to see someone who knows the difference. I'm far from as educated as you are in the science-y fields, but it does irk me nonetheless to see these statements as well.
  • yopeeps025
    yopeeps025 Posts: 8,680 Member
    Interesting thread.
  • rjmudlax13
    rjmudlax13 Posts: 900 Member
    I for one think it's nice to see someone who knows the difference. I'm far from as educated as you are in the science-y fields, but it does irk me nonetheless to see these statements as well.

    Yes. That is all I am trying to explain. You can use whatever wording you want. Personally I am fine with the statement "muscle weighs more than fat" as long as it's understood that all the parties have a good general understanding of the basic principles. Unfortunately, this is rarely the case on "both" sides of the argument.
  • BigT555
    BigT555 Posts: 2,067 Member
    or we could just let simple slips in proper language slide. nobody seems to b*tch when someone says "helium is lighter than air"

    You missed my point.

    Why the hell do I even bother. We are doomed as a species anyway.

    You're right! I'm just here to *****. You got it!

    I'm just going to keep my mouth shut and let stupidity perpetuate itself.
    i agree, if we are going to nitpick every misuse of the english language then indeed we are f*cked. I've studied chem and physics in uni too and i have zero problem with a minor misuse of a word when assumptions can be made about equating volume. nobody thinks a pound weighs more than a pound

    what was your point in the first place? you could pick out hundreds of words that are misused on a daily basis so why continue to point out this particular one?
  • sentaruu
    sentaruu Posts: 2,206 Member
    dude, get over it.
  • LotusAsh
    LotusAsh Posts: 294 Member
    nerds_zps9c444f49.jpg
  • riffraff2112
    riffraff2112 Posts: 1,756 Member
    So you would prefer people to say... "at the same pressure and temperature, an equal volume of fat weighs less than an equal volume of muscle" ? You must be a killer conversationalist :)

    To be honest I am on your side here. It bothers me a bit too, but I know what people are implying so I fill in the details myself when I hear these comments.

    The muscle vs fat weight comment is not nearly as annoying as the weight lifting will make me look bulky comment.
  • BigT555
    BigT555 Posts: 2,067 Member
    So you would prefer people to say... "at the same pressure and temperature, an equal volume of fat weighs less than an equal volume of muscle" ? You must be a killer conversationalist :)

    To be honest I am on your side here. It bothers me a bit too, but I know what people are implying so I fill in the details myself when I hear these comments.

    The muscle vs fat weight comment is not nearly as annoying as the weight lifting will make me look bulky comment.
    this brings up a good point, at different pressures fat could potentially be denser than muscle. so in a way, saying fat is less dense than muscle is just as inaccurate as saying muscle weighs more than fat
  • rjmudlax13
    rjmudlax13 Posts: 900 Member
    or we could just let simple slips in proper language slide. nobody seems to b*tch when someone says "helium is lighter than air"

    You missed my point.

    Why the hell do I even bother. We are doomed as a species anyway.

    You're right! I'm just here to *****. You got it!

    I'm just going to keep my mouth shut and let stupidity perpetuate itself.
    i agree, if we are going to nitpick every misuse of the english language then indeed we are f*cked. I've studied chem and physics in uni too and i have zero problem with a minor misuse of a word when assumptions can be made about equating volume. nobody thinks a pound weighs more than a pound

    what was your point in the first place? you could pick out hundreds of words that are misused on a daily basis so why continue to point out this particular one?

    No. We are f'ed as a species because people still believe global warming is a hoax. We are f'ed as a species because people still reject evolution. We are f'ed as a species because people still think vaccines are not necessary and cause more harm than good.

    I could care less what wording people use. I've stated this multiple times. I suggest you go back and read my whole post. I will be the first one to admit that I have a horrible grasp on the English language. I suck at public speaking, but try to improve. I'm bad at writing, but try to improve.

    One thing I know I am good at is engineering and science. Notice I said good. I am by no means a expert yet, but I am on my way.

    When I see people arguing over the fat and muscle thing and both "sides" of the argument are demonstrating a complete lack of BASIC scientific principles I get scared. I get scared because I wonder what there understanding of global warming is. I wonder what there understanding of vaccines is. I DO NOT CARE HOW THEY SAY IT. I care about their understanding of it.
  • rjmudlax13
    rjmudlax13 Posts: 900 Member
    So you would prefer people to say... "at the same pressure and temperature, an equal volume of fat weighs less than an equal volume of muscle" ? You must be a killer conversationalist :)

    To be honest I am on your side here. It bothers me a bit too, but I know what people are implying so I fill in the details myself when I hear these comments.

    The muscle vs fat weight comment is not nearly as annoying as the weight lifting will make me look bulky comment.

    Ah yes. Ad hominem arguments. You stuck it to me I suppose.
  • Hornsby
    Hornsby Posts: 10,322 Member
    Meh, most people (I would think) understand all three statements you are "clarifying". Too me the OP doesn't really clear anything up that isn't common sense.
  • BigT555
    BigT555 Posts: 2,067 Member
    No. We are f'ed as a species because people still believe global warming is a hoax. We are f'ed as a species because people still reject evolution. We are f'ed as a species because people still think vaccines are not necessary and cause more harm than good.

    I could care less what wording people use. I've stated this multiple times. I suggest you go back and read my whole post. I will be the first one to admit that I have a horrible grasp on the English language. I suck at public speaking, but try to improve. I'm bad at writing, but try to improve.

    One thing I know I am good at is engineering and science. Notice I said good. I am by no means a expert yet, but I am on my way.

    When I see people arguing over the fat and muscle thing and both "sides" of the argument are demonstrating a complete lack of BASIC scientific principles I get scared. I get scared because I wonder what there understanding of global warming is. I wonder what there understanding of vaccines is. I DO NOT CARE HOW THEY SAY IT. I care about their understanding of it.
    and if we didnt spend so much time arguing over simple miscommunications then maybe those problems wouldnt exist.

    i did read your whole post, but it comes back to the same thing. like i said before, nobody thinks a pound weighs more than a pound unless they have the mental capacity of a basketball. its just unnecessary drabbling at this point. is stating the difference between weight and density really going to fix any of the problems you mentioned?

    edited to remove the wall of quotes
  • stevencloser
    stevencloser Posts: 8,911 Member
    To add to this as a linguist:

    The reason why the incomplete statement "muscle weighs more than fat." Is understood by pretty much anyone even though no frame of reference is given is because of implication. Implication is an important part of human communication.

    It's the reason why "I'm studying tonight." is a valid answer to the question "Do you want to go to the movies with me?" even though it's not answering the question at all. The "No, I can't, because..." part is left out because it is unnecessary for understanding the sentence because your brain can decipher the unspoken part by itself within a split second. The same applies to "Muscle weighs more than fat." Any interpretation except "...if they're both the same volume." wouldn't make any sense so that's the interpretation your brain chooses and that's how you understand it even though that part didn't get said.

    The Japanese people are taking it even further, regularly just leaving out the complete subject of a sentence if they think it's obvious what the subject is.
  • rjmudlax13
    rjmudlax13 Posts: 900 Member
    Meh, most people (I would think) understand all three statements you are "clarifying". Too me the OP doesn't really clear anything up that isn't common sense.

    Actually, it is apparent that most people don't understand the difference between mass and weight.
  • jemhh
    jemhh Posts: 14,261 Member
    Look, my accountant-y brain can appreciate your compulsion to ensure that people understand the science behind what they are talking about. I would love if people didn't get all glassy eyed and sleepy when I crooned about debits and credits and assets and liabilities. (Heck, I would love it if people just knew their basic times tables.) But at a certain point we have to understand that it's not going to happen and there's no point in fixating on it. The majority of people understand the very basic idea that one pound of fat is larger in physical dimensions than is a pound of muscle and that's the bottom line. After that, be like Elsa and

    tumblr_mxh4i2zyUn1qdsm1jo1_500.gif
  • BigT555
    BigT555 Posts: 2,067 Member
    Meh, most people (I would think) understand all three statements you are "clarifying". Too me the OP doesn't really clear anything up that isn't common sense.

    Actually, it is apparent that most people don't understand the difference between mass and weight.
    thats not the argument here. besides, within the realm of the world we call earth, they are essentially the same thing, the difference is more philosophic than physical
  • gotolam
    gotolam Posts: 262 Member


    I apologize in advance for what is to come next, but it needed to be said…..

    No, it really didn't.

    Unfortunately, you're attitude is part of the problem.

    ETA: Grammar fail. I suck at life I guess. Really hope someone points that out as a way to disqualify me.

    NO, my attitude is not part of the problem. People who like to re-hash a fight that occurs once a week on this website are.
  • rjmudlax13
    rjmudlax13 Posts: 900 Member
    and if we didnt spend so much time arguing over simple miscommunications then maybe those problems wouldnt exist.

    i did read your whole post, but it comes back to the same thing. like i said before, nobody thinks a pound weighs more than a pound unless they have the mental capacity of a basketball. its just unnecessary drabbling at this point. is stating the difference between weight and density really going to fix any of the problems you mentioned?

    edited to remove the wall of quotes

    I am not arguing over "simple miscommunications." I am arguing over peoples misunderstanding of basic scientific principles.

    Yes. I do think that effectively teaching children (and ignorant adults) basic science and math will help these problems. It's not "unnecessary drabbling" when it comes to that. Are you saying all the people throughout history that have contributed amazing scientific advances didn't care about or understood basic science?

    I guess my communication is terrible because you still don't understand my point even though I've explained over and over again that I don't really care about the semantics. It's the understanding. How about we talk about peoples understanding of Calories? Would that be less controversial for you? I was using the muscle fat thing as an example.

    Are you saying you believe everyone on these forums alone have a pretty good understanding of basic science?

    I use the statement "muscle weighs more than fat" all the time. It bothers me when people say that I am "wrong" and when I ask why they say things like "a pound equals a pound." This is a tell tale sign that they don't fully understand the concept and probably are just reiterating something they read on the Internets in an attempt to appear smart and important.

    By the way, we are agreeing and you don't even realize it.
  • rjmudlax13
    rjmudlax13 Posts: 900 Member
    Meh, most people (I would think) understand all three statements you are "clarifying". Too me the OP doesn't really clear anything up that isn't common sense.

    Actually, it is apparent that most people don't understand the difference between mass and weight.
    thats not the argument here. besides, within the realm of the world we call earth, they are essentially the same thing, the difference is more philosophic than physical

    Boy, I hope you don't work for NASA.
  • sentaruu
    sentaruu Posts: 2,206 Member
    or we could just let simple slips in proper language slide. nobody seems to b*tch when someone says "helium is lighter than air"

    You missed my point.

    Why the hell do I even bother. We are doomed as a species anyway.

    You're right! I'm just here to *****. You got it!

    I'm just going to keep my mouth shut and let stupidity perpetuate itself.
    i agree, if we are going to nitpick every misuse of the english language then indeed we are f*cked. I've studied chem and physics in uni too and i have zero problem with a minor misuse of a word when assumptions can be made about equating volume. nobody thinks a pound weighs more than a pound

    what was your point in the first place? you could pick out hundreds of words that are misused on a daily basis so why continue to point out this particular one?

    No. We are f'ed as a species because people still believe global warming is a hoax. We are f'ed as a species because people still reject evolution. We are f'ed as a species because people still think vaccines are not necessary and cause more harm than good.

    I could care less what wording people use. I've stated this multiple times. I suggest you go back and read my whole post. I will be the first one to admit that I have a horrible grasp on the English language. I suck at public speaking, but try to improve. I'm bad at writing, but try to improve.

    One thing I know I am good at is engineering and science. Notice I said good. I am by no means a expert yet, but I am on my way.

    When I see people arguing over the fat and muscle thing and both "sides" of the argument are demonstrating a complete lack of BASIC scientific principles I get scared. I get scared because I wonder what there understanding of global warming is. I wonder what there understanding of vaccines is. I DO NOT CARE HOW THEY SAY IT. I care about their understanding of it.

    could you?
  • Hornsby
    Hornsby Posts: 10,322 Member
    and if we didnt spend so much time arguing over simple miscommunications then maybe those problems wouldnt exist.

    i did read your whole post, but it comes back to the same thing. like i said before, nobody thinks a pound weighs more than a pound unless they have the mental capacity of a basketball. its just unnecessary drabbling at this point. is stating the difference between weight and density really going to fix any of the problems you mentioned?

    edited to remove the wall of quotes


    I use the statement "muscle weighs more than fat" all the time. It bothers me when people say that I am "wrong" and when I ask why they say things like "a pound equals a pound." This is a tell tale sign that they don't fully understand the concept and probably are just reiterating something they read on the Internets in an attempt to appear smart and important.

    I have no idea how a replying to "muscles weighs more than fat" with "a pound is a pound" is a tell tale sign that they don't understand the concept.
  • yopeeps025
    yopeeps025 Posts: 8,680 Member
    Meh, most people (I would think) understand all three statements you are "clarifying". Too me the OP doesn't really clear anything up that isn't common sense.

    Actually, it is apparent that most people don't understand the difference between mass and weight.
    thats not the argument here. besides, within the realm of the world we call earth, they are essentially the same thing, the difference is more philosophic than physical

    Boy, I hope you don't work for NASA.

    LOL the arguments on MFP.
  • BigT555
    BigT555 Posts: 2,067 Member
    By the way, we are agreeing and you don't even realize it.
    we are disagreeing, i have said numerous times now that nobody thinks a pound weighs more than a pound, yet you seem to think that some people do

    if on the off chance that they dont, then i think its pretty fair to assume that they arent going to be making any significant contributions to science other than as a cadaver

    children get this lesson by default in science classes. again even if they didnt i still doubt they would think a pound weighs more than a pound. even if they dont know the proper term, people know the principles of density, volume and mass through real world implications as simple as a helium balloon floating upwards
  • rjmudlax13
    rjmudlax13 Posts: 900 Member


    I apologize in advance for what is to come next, but it needed to be said…..

    No, it really didn't.

    Unfortunately, you're attitude is part of the problem.

    ETA: Grammar fail. I suck at life I guess. Really hope someone points that out as a way to disqualify me.

    NO, my attitude is not part of the problem. People who like to re-hash a fight that occurs once a week on this website are.

    I am not rehashing any fight. This topic transcends the muscle fat argument. Your attitude reflects a lot of people's attitudes about science. The attitude that they really don't care or see it as important.
  • RllyGudTweetr
    RllyGudTweetr Posts: 2,019 Member
    popcorn49.gif
  • BigT555
    BigT555 Posts: 2,067 Member
    Meh, most people (I would think) understand all three statements you are "clarifying". Too me the OP doesn't really clear anything up that isn't common sense.

    Actually, it is apparent that most people don't understand the difference between mass and weight.
    thats not the argument here. besides, within the realm of the world we call earth, they are essentially the same thing, the difference is more philosophic than physical

    Boy, I hope you don't work for NASA.
    RE; "within the realm of the world we call earth"
    mass equals weight on earth. even difference in altitude at ground level only amounts to less than a pound difference in weight

    and yes you are re-hashing the argument because it always comes back to the same thing, the implication of similar volumes leading to someone thinking there is a knowledge gap (which undoubtedly there is to an extent, but to the point where a pound weighs more than a pound? dont think so)