Fat or breast? new study aims to solve puberty puzzle in overweight girls

This study looks at whether overweight girls start puberty earlier than girls of normal weight. Researchers will use breast ultrasound and other tests to tell the difference between breast tissue and fatty tissue. The study involves 150 healthy girls ages 8-14 who have some breast development but have not started their period. Participants will have physical exams, ultrasounds, blood and urine tests, and X-rays to measure body fat and bone maturity.