Describe the difference between prolonged fasting/starvation versus cachexia in children with cancer.

Describe the difference between prolonged fasting/starvation versus cachexia in children with cancer.

• A. Cachexia is an advanced wasting with depletion of skeletal muscle and adipose tissue and loss of protein-sparing mechanisms; prolonged fasting preserves lean tissue through protein conservation and lower energy expenditure.
• B. Prolonged fasting causes greater muscle loss than cachexia.
• C. Cachexia only affects adipose tissue, not muscle.
• D. Fasting increases energy expenditure.

Answer: (A)

Cachexia in children with cancer is a disease-driven, ongoing catabolic state that relentlessly wastes skeletal muscle and adipose tissue while disrupting normal protein metabolism. Inflammatory signals and tumor-derived factors drive proteolysis and reduced protein synthesis, so the body loses lean mass despite intake, often with little hope of reversal without targeted therapies. Prolonged fasting, on the other hand, triggers an adaptive response that conserves protein and lowers energy expenditure. Ketone bodies and fat oxidation become primary fuels, helping to spare lean tissue in the short term, while metabolic rate can decrease to conserve energy. Thus, the described distinction is that cachexia involves active, ongoing loss of muscle and fat with loss of protein-sparing mechanisms, whereas prolonged fasting preserves lean tissue through protein conservation and a lower energy expenditure. The other statements don’t fit this pattern: fasting does not typically cause more muscle loss than cachexia, cachexia does affect muscle, and fasting generally does not increase energy expenditure.

Cachexia in children with cancer is a disease-driven, ongoing catabolic state that relentlessly wastes skeletal muscle and adipose tissue while disrupting normal protein metabolism. Inflammatory signals and tumor-derived factors drive proteolysis and reduced protein synthesis, so the body loses lean mass despite intake, often with little hope of reversal without targeted therapies. Prolonged fasting, on the other hand, triggers an adaptive response that conserves protein and lowers energy expenditure. Ketone bodies and fat oxidation become primary fuels, helping to spare lean tissue in the short term, while metabolic rate can decrease to conserve energy.

Thus, the described distinction is that cachexia involves active, ongoing loss of muscle and fat with loss of protein-sparing mechanisms, whereas prolonged fasting preserves lean tissue through protein conservation and a lower energy expenditure. The other statements don’t fit this pattern: fasting does not typically cause more muscle loss than cachexia, cachexia does affect muscle, and fasting generally does not increase energy expenditure.