When you sprinkle cheese on your pasta, you may be getting more than you bargained for.

FOX's Lisa Lacerra explains:

Some companies that promise 100% Parmesan cheese have been adding cellulose, a common food additive made from wood pulp, that's according to an independent study launched by Bloomberg News.

A lab test finding that products like Jewel Osco's Essential Everyday 100% Parmesan cheese was 8.8% cellulose, while Kraft's has 3.8% cellulose.

Cellulose is often added to food to give texture, according to John Coupland, a Penn State University professor of food science.

He says it's used in the cheese to keep it from sticking together and getting oily.

Lisa Lacerra, FOX News.