I am 20 years old and I have beeen lifting for a about 2 and a half years. I have gained about 15 to 20 pounds of muscle over this time. I have a VERY fast metabolism so its hard for me to put on weight. I have to eat over 4000 calories a day just to put on any muscle. The reason I am telling you all this is because i have an inguinal hernia and I have to have surgery. because of this I wont be able to lift for 4 to 6 weeks and I am afraid since my metablolism is so fast I am going to lose ALL the muscle I have gained over the past couple of years. What is your take on this? How much muscle mass do you think I will lose and how long do you think it will take to regain it? Thanks.