Abstract: Described are medicaments and methods of treating or preventing metabolic bone diseases, such as Critical Illness Related Metabolic Bone Disease or of critical illness induced Osteopenia secondary to ICU Admission by sufficient autophagy inducing compound to inhibit or suppress critical illness enhanced osteoclastogenesis or increased osteoclast differentiation. The methods include administering of an autophagy activating compound to a mammal to: treat or prevent a bone degenerative disorder; slow bone deterioration; restore lost bone; maintain bone mass and/or bone quality or inhibit bone resorption in particularly by inhibiting or reducing a process by which osteoclasts break down bone and release the minerals resulting in a transfer of calcium from bone fluid to the blood. Also described are methods for administering the autophagy activating compound to treat a bone disorder of hyperresorption of bone and/or enhanced activation of osteoclasts.