How come you never exercise and eat all you want and you are still skinny?

If you have a fast metabolism, working out with weights can help you gain weight. Make sure you eat well and regularly, and make sure you eat enough protein to build the muscle instead of just burning it off. Life is just not fair. Some people have faster metabolisms than the rest of us. They seem to eat whatever they want, never work out and are still skinny. Others are constantly in motion, burning up all the calories they consume. Having a high proportion of muscle is helpful, since muscle burns more calories than fat. Men often have an advantage in this area. Also, estrogen encourages our bodies to store fat, anther disadvantage for women. Most people's metabolisms slow as they age, so your skinny friend may have a little more trouble later in life. For now, focus on positive traits you have that your friend doesn't, like intelligence or a great smile! It happened to me once because I had a dangerous condition called hyperthyroidism, which causes the metabolism to go too fast. It was horrible, I was hungry all the type and looked like a twig.