Table 1 Inclusion and exclusion criteria

Inclusion criteria

• Nutritional Risk Screening (NRS 2002) total score ≥ 3 points according to routine screening at admission within 72 h [25]

• Expected hospital LOS ≥ 3 days after screening (as estimated by the treating physician)

• Patient qualifies for ONS and approves prescription

• Age > 18 years

• Willingness and ability to provide informed consent

Exclusion criteria

• Initially admitted to critical care unit

• Immediate post-operative phase (< 7 days post-surgery)

• Dysphagia with the inability to swallow liquids

• Admitted with or scheduled for supplemental or total enteral nutrition and/or parenteral nutrition

• Mini Mental State examination < 16 points

• Hospitalization due to anorexia nervosa, acute pancreatitis, or acute liver failure

• Patients with cystic fibrosis, short bowel syndrome, or after gastric bypass surgery

• Terminal condition (end of life situation)

• Poor German language skills (study language)