Muscles weigh more than fat, that's a fact. So when you start working out and use weights like dumb bells or the new exercise called Kettlebell workouts , you will probably be surprised that you gained weight or didn't lose any. That's because you're gaining muscles and this is very important if you want to lose weight. Muscles burn more calories so if you have more muscles in your body, you are more likely to burn more calories. Burning more calories than you are consuming means you're going to lose weight. So it is important not to obsess on the numbers you see on the scale. Look instead on how your clothes fit.