Olestra is a fat substitute used in certain low-fat or fat-free food products. It is a non-digestible compound that mimics the properties of fat without providing calories. Olestra is produced through a process called interesterification, where a fatty acid molecule is synthesized by combining a sugar molecule (such as sucrose) with multiple fatty acids (such as vegetable oil). The resulting compound has a structure that the body’s enzymes cannot break down and digest, so it passes through the digestive system without being absorbed. This characteristic allows Olestra to provide the mouthfeel and texture of fat in foods while contributing minimal or no calories. Olestra has been used in products like certain potato chips and snack foods, providing a lower-calorie option.