 Obesity during adolescence, a critical time for bone development, may impair mineral accrual and reduce bone strength, leading to greater fracture risk during adolescence and later in life. This study seeks to determine the effect of obesity and accompanying metabolic changes insulin resistance and inflammation on bone mineral accrual and related changes in structure and strength in young girls. The information is critical to developing effective prevention strategies to counter the linked risks of obesity and osteoporosis, both major public health concerns. 