Does muscle really weigh more than fat?

Not sure if I should ask this on "Fitness" or "Weight Loss", so I kinda just winged it, sorry if I'm wrong. 

I had always just thought that "muscle weighs more than fat" is something that people told themselves when they were gaining weight but trying to lose it, or when they reached a weight loss plateu, but I've been wondering about it lately. If I notice I'm gaining muscle and getting firmer or maybe even that little 'cut' look, should I be gaining weight? If I'm not, am I not really gaining any muscle?

I've heard countless dieters say 'muscle weighs more than fat', and my mom even told me when I got down about the four pounds I gained...but even I knew that was because I've been both retaining water AND going over my calorie goal for a week or so. When MSN did something about the top 7 diet myths, they said it wasn't true...that a pound of muscle and a pound of fat both weigh, shockingly, a pound. Made sense 

The thing is though, muscle takes up far less room than fat does. You can have the same amount of space taken up by fat and muscle, and the muscle will be much smaller. Yes, of course they weigh the same if they're both a pound, but it's more of a density thing, not a weight thing. You will look much better at 140 lbs with lots of muscle than you will at 140 lbs made up of all fat. Way to go MSN, being retarded.

pound for pound, yes they are the same. But muscle is denser so more of it takes up less space. So if you compared the same mass amount the muscle would weigh more. Hope that helps

Well, a pound is a pound is a pound, so a pound of muscle does not weigh more than a pound of fat.  But....  muscle is denser than fat so a pound of muscle takes up less space than a pound of fat (about 20% less, IIRC).  So you can actually be smaller and weigh more if you have less body fat and more muscle.  This is why people say muscle "weighs" more than fat.

The tough thing is that it is very hard to gain substantial amounts of muscle when you are dieting.  You need to lift pretty heavy weights and not be in too much of a defecit to gain even a pound or two of real muscle, so a lot of weight gain might just be water weight or your muscles storing more glycogen.

The important thing is that you are reducing your body fat percentage.  Focus on reducing your  %body fat and not on achieving a specific weight and you'll be better off.

the more muscular you are, the less meaningful the BMI index is.

So far as which one "looks" heavier, it would be fat.  A pound of fat takes up more volume (lower density) than a pound of muscle.

Losing weight and gaining muscle (measurable amounts of muscle) is a difficult thing to do because of your body going through the catabolic process to lose weight.  (Gaining muscle mass is an anabolic process)

Some people are lucky where they can lose weight while gaining muscle mass at the same time.  But the average person won't see a measurable difference.

The only true way to determine the answer to your question is by measuring your body fat percentage.  That, in my opinion, is the true measurement of progress.

Original Post by watergirl:

the more muscular you are, the less meaningful the BMI index is.

Haha...so true 

That's what had me confused! A pound of anything and pound of something else will both weight a pound...but it was possible muscle simply weighed more POUNDS than fat. And a person would look a lot better, even if they were 200 pounds, if it were all muscle..except if you're 5'0 with a super small frame like me, in which case you'd look like one of those scary body-builder women.

"Muscle is denser than fat" doesn't have the same ring to it as "muscle is heavier than fat," so I guess that's why it's less memorable despite actually making sense.

A cup of fat weighs less than a cup of muscle. ;)

So, do bowling balls weigh more than feathers? 

Well, a ton of feathers weighs the same as a ton of bowling balls, but a truckload of bowling balls weighs more than a truckload of feathers. 

Same with fat/muscle.  Muscle is denser than fat, just like bowling balls are denser than feathers. 

Original Post by girlfighting27:

pound for pound, yes they are the same.

 pound for pound everything weighs the same so there really isn't any point in comparing how much 2 things weigh 'pound for pound'.

Original Post by floggingsully:

Original Post by girlfighting27:

pound for pound, yes they are the same.

 pound for pound everything weighs the same so there really isn't any point in comparing how much 2 things weigh 'pound for pound'.

new to dry wit, eh?

if you made a person mold and made two people in that mold (mould for you UK'ers,  i think), and made one of them with 8% body fat and one with 30%, the "leaner" one would weigh more.

cubic inch for cubic inch, muscle weighs more than fat.

this is what density is.

please call your congressman (MP?) and demand more funding for science education. i'm sort of not kidding.

According to this site - http://www.outsidemag.com/bodywork/mrfit/arch ives/199910/19991006.html :

The density of fat is about 0.9g/cm3, whereas the density of lean tissue is
1.1g/cm3. In other, more unscientific words, lean tissue is about 22% more dense than fat tissue.