1. Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands.
2. Department of Surgery, Gelre Hospitals, Apeldoorn, The Netherlands.
3. Department of Surgery, VU Medical Center, Amsterdam, The Netherlands.
4. Division of Human Nutrition, Wageningen University, The Netherlands.
5. Department of Geriatrics, Gelre Hospitals, The Netherlands.
6. Department of Internal Medicine, University of Groningen, The Netherlands.