Some fat is essential in our diets - vitamins A, D, E, and K, and essential fatty acids are vital to good health and body functions. But consumer demand for reduced fat foods keeps food scientists busy creating fat replacers that successfully mimic fat. The technology behind this focuses on determining what function a type of fat has in a particular food and then finding the right ingredients that will successfully replace the fat. Fat replacers that are carbohydrate based have been used safely for many years, e.g., starches, gums, fiber. These are used in baked and cooked foods but not in frying.
Whey protein is a common protein based fat replacer.
Olestra is fat-based but it passes through the body unabsorbed. It is approved for some snack foods that are usually fried in fat, such as chips. It has not yet been approved for other applications. The use of olestra in certain snack foods was approved in 1996. The US Food and Drug Administration requires fortification of olestra products with the fat-soluble vitamins, A, D, E, and K. Additionally, labeling must state that olestra may cause abdominal cramping and loose stools.