The US Food and Drug Administration has approved the use of a Procter & Gamble fat substitute, olestra, in pre-packed microwave popcorn.

The food and consumer goods company has used olestra in ready-to-eat packaged snacks before, such as P&G's Fat Free Pringles, but not in products that require heating before they are consumed, reported the Associated Press.

Olestra, which is made of sugar and soybeans, has a similar taste to fat but it is not digested by the body.

Olean, P&G's brand name for olestra, is also used in Frito-Lay's Wow chips and certain products made by Utz Quality Foods, AP said. Although P&G sold off its Olean plant, it still retains ownership of the brand.