Girls build 60%-80% of their bone mass by the age of 18. The years around puberty are the most critical. Whenever teange girls do not eat enough to meet their energy requirements they face an "energy deficit". In 2006, the Foundation for Osteoporosis Research and Education and American Bone Health convened a group of leading scientists, educators and researchers to discuss the effects of competitive sports and nutrition on health bone development in teenage and pre-teen girls. The Athletic Energy Deficit Prevention Project aims to improve bone acquisition and reduce other complications that result from athletic energy deficit syndrome and poor nutrition. We want to encourage a generation of young female athletes to be strong, healthy and competitive for a lifetime. Go to American Bone Health