Fat oxidation, also known as lipolysis, breaks down fats (triglycerides) into smaller molecules that the body can use for energy. This primarily occurs in the mitochondria of cells. The main products are:
- Free fatty acids (FFAs): These are the building blocks of fats and are transported to the mitochondria for further processing.
- Glycerol: This is a three-carbon molecule also released during fat breakdown. It can be used for energy production or converted to glucose.
Under conditions of stress, such as fasting or a high-fat diet, the liver's fat oxidation also produces ketone bodies. These are four-carbon acids that can serve as an alternative energy source for the brain and other tissues when glucose levels are low.
The process of fat oxidation is crucial for energy metabolism. The rate of fat oxidation is influenced by factors such as exercise intensity and duration. For example, fat oxidation rates increase at moderate exercise intensities before decreasing at higher intensities. See: Optimizing fat oxidation through exercise and diet
The efficiency of fat oxidation depends on several factors, including the availability of carnitine, a cofactor that helps transport long-chain fatty acids into the mitochondria for oxidation. See: Carnitine - Health Professional Fact Sheet. Impaired fat oxidation can contribute to weight gain and resistance to weight loss. See: Beyond appetite regulation: Targeting energy expenditure, fat oxidation, and mitochondrial function to combat obesity.
In summary, fat oxidation produces free fatty acids, glycerol, and, under certain conditions, ketone bodies. These molecules provide the body with energy. The process is complex and influenced by various factors, but the core result is the generation of usable energy from stored fat.
