- An ester of fatty acids and sugar, which behaves in cooking like oil or fat but which is not absorbed by the human body. Thus it can be used as a non-fattening fat. It has been licensed in the USA for cooked snack foods such as crisps. Because of its ability to sequester vitamins A, D, E and K plus carotenes and possibly other nutrients, foods cooked with it carry a health warning. Extra vitamins are required to be added back to the food which uses olestra.