Owing to improved medical care and treatment our society is rapidly aging. As a result, age-related diseases are also on the rise. These have a strong impact on the aging individual as well as on our society. Age-related maladies involve multiple and often distinct organ systems. However, they share a common denominator; the mitochondria—the powerhouse of the cell. In health, mitochondria efficiently process nutrients and convert them to useable cellular energy. Aged mitochondria lose this capacity as a consequence of accumulating damage. My research group aims to elucidate the molecular pathways underlying metabolic aging, especially in the mitochondria. We focus on 1) mitochondrial fat metabolism, as well as on 2) mitochondrial stress pathways counteracting the age-related functional decline. We translate these findings to mammalian systems and aim to resolve pathophysiological mechanisms underlying aging and metabolic diseases.