Malnutrition and low muscle mass (sarcopenia) are common problems in patients with cancer. However, a low muscle mass is associated with negative clinical outcomes in patients with cancer. Therefore, it is very important to maintain muscle mass in this population. This study aims to investigate the effect of an oral nutritional supplement on skeletal muscle mass during anti-cancer treatment.

Inclusion Criteria:

• Diagnosis of stage III or IV colorectal or non-small cell lung cancer
• Scheduled for the first cycle of any line of a systemic treatment: chemotherapy, concurrent chemoradiotherapy, immunotherapy or targeted treatment with a planned duration of at least 9 weeks
• Performance status Eastern Cooperative Oncology Group (ECOG) score 0 or 1
• Age ≥ 18 years

Exclusion Criteria:

• Weight loss >10% in the last 6 months
• Body Mass Index > 30.0 kg/m2
• Life expectancy < 3 months
• Receiving enteral (tube) or parenteral nutrition
• Presence of ileostoma or ileal pouch (except for an ileostomy at or near the terminal ileum which does not affect absorption of nutrients other than sodium, potassium, and water, in the opinion of the investigator)
• Allergy to cow's milk protein, soy or fish, requiring a fibre-free diet or suffering galactosemia or lactose intolerance
• Known pregnancy or lactation
• Current alcohol or drug abuse in the opinion of the investigator
• Wearing an electronic implant and/or pacemaker
• Investigator's uncertainty about the willingness or ability of the subject to comply with the protocol requirements
• Participation in any other studies involving investigational or marketed products concomitantly or within 14 days prior to entry into the study