 [ Symptoms ] can young children age 2 get measles after having 1 mmr vaccine at 12 months of age  my daughter age 2 has a rash and fever the rash looks very similar to measles [ Disease ] 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