Effect of Continuous Versus Cyclic Daytime Enteral Nutrition on Circadian Rhythms in Critical Illness

Inclusion Criteria: * Age ≥ 18 years old * Receiving of or intention to start enteral nutrition via nasogastric or nasoduodenal tube * Arterial line * Expected duration of ICU admission \> 48 hours Exclusion Criteria: * Receiving parenteral nutrition * Prior night-time (20.00h - 8.00h) enteral tube feeding within the same hospitalization before study inclusion * Readmission to ICU with prior study inclusion * Chronic enteral tube feeding prior to current admission * Presence of one or more contraindications of enteral feeding and/or at significant risk for gastrointestinal tolerance according to standard protocol (including but not limited to gastrointestinal haemorrhage, intestinal ischemia or necrosis, impaired digestive tract integrity due to obstruction or perforation, gastrectomy, enterectomy, history of gastroparesis or oesophageal dysmotility or expected surgery within 24 hours) * Patients with glycaemic emergency (including but not limited to hyperglycaemic hyperosmolar nonketotic coma, diabetic ketoacidosis, severe hypoglycaemia resulting in ICU admission) or patients controlling their glucose levels and insulin dosing via continuous glucose monitoring * Expected death within 24 hours * Do-not-resuscitate (DNR) order * Treatment with extracorporeal membrane oxygenation * Severe neurological damage (significant neurological abnormalities such as bleeding, ischemia, neurotrauma or severe encephalopathy with Glasgow Coma Scale ≤ 8) * Suspected or confirmed pregnancy