a pound of fat and a pound of muscle weigh the same. the difference is that a pound of muscle is denser and therefore takes up much less surface area than fat. if you were to look at five pounds of muscle and five pounds of fat the fat would take up much more volume. it is possible for you to lose fat and gain muscle without a change in body weight because you are building muscle through exercising. sometimes your body fat percentage can be a better indicator than the number on the scale and you can get this tested by a medical professional. weight can fluctuate slightly based on several factors. here are some links that you may find helpful to share with your wife: webmd fitness & exercise guide can you gain muscle & lose fat at the same time? fitness & exercise community with rich weil cde med why do you gain back weight? diet community with pam peeke md the webmd answers staff muscle weighs more than fat.
what weighs more muscle or fat? . im just wondering about weight gain due to muscle growth. my wife has been working out for some time with weights and cardio training but she is finding that her weight has been fluctuating and at times gains weight a little bit.