I have a 15 year old male athelete who has been strongly encouraged to use a weight gainer. He has started taking in over 10,000 calories a day. I am concerned as to how this will affect his growing body and his vital organs. Is it safe for teens to use this stuff? How often and how much? Will he in four or five years start keeping weight on and become a heavy adult. I am at a total loss as to what advice to give him. He is determined to gain weight and beef up. I don't want to take such a hard line that he starts looking for steroids, but then if he continues to use this will he eventually turn to steroids to beef up even more? Help. We are struggling with where to find some sound wisdom. Our doctor is not experienced with this. Any help would be appreciated. Thanks, A lost parent.