Intermittent Fasting Versus Carbohydrate Drinks Before Surgery

Inclusion Criteria: * Undergoing elective orthopaedic surgery; * Intermediate, major or complex surgery according to the Surgical Outcome Risk Tool (SORT; http://www.sortsurgery.com/) severity of surgery classification; * Scheduled for surgery at least 17 days from the date of screening; * Motivated to follow a time restricted feeding regimen. * Willing and able to provide written informed consent. Exclusion Criteria: * History of diabetes mellitus; * History of feeding or eating disorders; * History of delayed gastric emptying or gastro-oesophageal reflux * Active malignancy * Patients classified as ASA IV by the attending anaesthetist; * BMI \< 18.5 or ≥ 35; * Outpatient or day case surgery; * Palliative surgery; * Participation in another clinical trial that is interfering with the procedures or outcomes of the PRINCESS trial; * Patients unable to fully comply to study needs (e.g. legally incapable patients or patients unable to communicate in Dutch).