It doesn't. A pound of fat takes up a lot more space though. Your personal goal (it seems like) is to look good naked or with a bathing suit on. Don't focus on the number of pounds you weigh. And to what that person said...this is a genuine post/genuine problem, whether it's about your concerns over the number of pounds a scale says you weigh, or a poor self-image resulting in attention seeking behavior, or most likely, somewhere in between.