Inclusion Criteria:  Advanced lung or gastrointestinal cancer patients not eligible for curative treatment WHO performance status of ≤ 2 Able to perform physical exercise estimated by the treating physician Estimated life expectancy of ≥ 6 months Patient must give written informed consent  Exclusion Criteria:  Intake of supplements with high-dose branched-chain amino acids within one month Enteral (except oral nutritional supplements) and/or parenteral nutrition within one month History of ileus within previous month Milk protein allergy The patient cannot understand the trial-specific content due to linguistic, psychological or disease reasons Age < 18 years