Myth:  Muscle “Weighs” More Than Fat... 

Reality: A pound is a pound is a pound—unless you’re defying the laws of physics. No substance weighs more then another one unless it actually weighs more. Simply put: One pound of fat weighs the same as one pound of muscle.  The difference is that fat is bulkier than muscle tissue and takes up more space under the skin. In fact, one pound of fat is roughly the size of a small grapefruit; one pound of muscle is about the size of a tangerine. But that tangerine is active tissue, meaning that it burns more calories at rest than fat does.