Hello, I am a 14 year-old male, I weigh about 120lbs and I am around 5'8. I know that this is underweight, and I want to make a change to that. I was just wondering, would it be healthy if I slowly (by slowly, I mean a year or two) worked my way up to gaining 30 lbs of mostly muscle by eating a healthy calorie rich diet strictly limiting saturated fat, sodium bad cholesterol, etc. and including lots of protein. Along with this, I would include some cardio workouts along with light weight lifting with high repetitions. Would I still maintain healthy organ systems, and will I be all around healthy still? I've heard that in taking too much protein is bad and that it puts stress on the liver and kidneys. If this is true, what is a healthy amount of protein that I can intake daily to maintain or possibly improve health while bulking up on muscle mass and looking toned. Are there any other tips you have for me? Thanks for the help doctor!