Autophagy, a type of cellular recycling program, influences many aspects of health and disease, including cancer, neurodegenerative disease, and aging. Nutrient sensing is integral to autophagy, particularly concentrations of acetyl CoA, an end product of protein, fat, and carbohydrate metabolism. Modulating autophagy – through fasting and exercise (which both increase acetyl CoA) or intake of nutrients like spermidine – represents a promising therapeutic approach for extending human lifespan and healthspan. This Aliquot segment features Dr. Guido Kroemer, an expert in immunology, cancer biology, aging, and autophagy.