Olestra is a polyester of sucrose known as a fat substitute in the food industry. The trademark name is Olean. It does not contain any calori or energy. For this reason, it is an important fat substitute in reducing the risk of obesity, which is a significant health problem of current times, resulting from consuming diets rich in animal and vegetable oils and insufficient physical exercise. It has a taste, flavor and cooking properties similar to the traditional fats and oils. The use of olestra has been approved by the US Food and Drug Administration (FDA) for the production of a limited number of foods with low fat content (such as packaged ready-made salty snacks, popcorn and potato chips). Although there are positive opinions revealed from many studies carried on humans and animals about olestra, there are also some negative opinions. Olestra prevents the absorption of fat-soluble vitamins A, D, E and K. However, as it is not absorbed from the digestive system, there is no increase in weight and serum cholesterol levels. Also, olestra does not have toxic, carcinogenic, teratogenic and mutagenic effects. Olestra is degradable in the environment by the effect of aerobic microorganisms and fungi isolated from soil and waste.