1. Pediatric Surgery Department, Complejo Asistencial Universitario de León, 24008 León, Spain
2. Department of Preventive Medicine and Public Health, School of Medicine, University of Navarra, 31008 Pamplona, Spain
3. IdiSNA, Instituto de Investigación Sanitaria de Navarra, 31008 Pamplona, Spain
4. CIBER de Fisiopatología de la Obesidad y la Nutrición, Instituto de Salud Carlos III, 28029 Madrid, Spain
5. Department of Anesthesiology, University of Navarra Clinic, 31008 Pamplona, Spain
6. Medical Engineering Laboratory, School of Medicine, University of Navarra, 31008 Pamplona, Spain