1. Department of Family Medicine, Cheil General Hospital and Women's Health Care Center, Kwandong University, Seoul, Korea
2. Department of Family Medicine, College of Medicine, Korea University, Seoul, Korea
3. Division of Biostatistics, Korea University, Seoul, Korea
4. Department of Family Medicine, Eulji Medical University, Seoul, Korea
5. Human Ecology Research Center, Seoul National University, Seoul, Korea
6. Department of Public Health Nutrition, Seoul National University, Seoul, Korea
7. Department of Family Medicine, University of Ulsan College of Medicine, Seoul, Korea