Overview of Fatty Acid and Glycerol Metabolism Disorders By Matt Demczko, MD, Mitochondrial Medicine, Children's Hospital of Philadelphia Reviewed / Revised Oct 2021 | Modified Sep 2022 View Patient Education More Information Topic Resources Ketone Metabolism Disorders Other Fat Metabolism Disorders Fatty acids are the preferred energy source for the heart and an important energy source for skeletal muscle during prolonged exertion.