1. Department of Pediatrics, School of Medicine, Ewha Womans University, Seoul, Korea.
2. Department of Pediatrics, College of Medicine, Inje University, Seoul, Korea.
3. Department of Preventive Medicine, College of Medicine, Ajou University, Suwon, Korea.
4. Department of Physical Education, Yonsei University, Seoul, Korea.
5. Department of Food and Nutrition, Sungshin Women's University, Seoul, Korea.
6. Department of Pediatrics, College of Medicine, Ajou University, Suwon, Korea.
7. Department of Pediatrics, College of Medicine, Hanyang University, Seoul, Korea.
8. Department of Pediatrics, College of Medicine, Seoul National University, Seoul, Korea.