My daughter is a 14-year old competative swimmer and a vegan. She has been vegan all her life. There is no reason why your child can't be a successful athlete and vegetarian. I understand your concerns about getting enough calories. Teenagers seem to eat constantly anyway, and adding regular, extensive exercise to the mix makes it more difficult to ensure adequate caloric (energy)intake. You and your child should first see if there's a sports or other licensed nutritionist in your area. For now, make sure you are substituing beans, tofu, dairy or some other protein source for the meat. Protein is required for muscle repair as well as other things. Fluid management is also a concern for athletes, but being vegetarian helps a bit since fruits and veggies contain water. If your child still eats dairy products, there shouldn't be a problem with nutrients, just watch the fats. Be sure there's a variety in the meals that are prepared. You may find that a vegetarian food change will benefit not only your child, but the rest of your family as well. Good luck!