The present invention relates to myostatin antagonists, for the treatment of cancer cachexia, and cancer cachexia due to chemotherapeutic treatment. In particular, the myostatin antagonist bimagrumab was found to be beneficial in the treatment of cancer cachexia by reducing body weight loss. The present invention also relates to combinations and uses of a myostatin antagonist and an mTOR inhibitor for treating cancer cachexia by reducing, maintaining or increasing body weight loss or for use in treating age-related conditions.