1. Department of Digestive Surgery, University Hospital Miguel Servet, 50009 Zaragoza, Spain
2. Department of Nutrition and Dietetics, Bradford Teaching Hospitals NHS Foundation Trust, Bradford BD9 6RJ, UK
3. City Dietitians, London WC2E 7PP, UK
4. Gastroenterology, Hepatology and Nutrition Unit, University Hospital San Jorge, 22004 Huesca, Spain
5. Faculty of Health and Sport Sciences, University of Zaragoza, 22002 Huesca, Spain
6. Department of Medicine, Faculty of Health and Sport Sciences, University of Zaragoza, 22002 Huesca, Spain
7. Aragon Health Research Institute (IIS Aragon), University of Zaragoza, 22002 Huesca, Spain