William C. Dietz is a prominent American physician and researcher known for his work in the field of obesity and nutrition. He has contributed significantly to understanding the causes and consequences of obesity, particularly in children and adolescents. His research has influenced public health policies and initiatives aimed at combating obesity in the United States. Dietz has held various leadership positions, including serving as the director of the Division of Nutrition, Physical Activity, and Obesity at the Centers for Disease Control and Prevention (CDC). He has published numerous articles and studies, helping to raise awareness about the importance of healthy eating and physical activity in preventing obesity-related health issues.