When you think about wood pulp, you probably picture the stuff that lined your hamster’s cage, not the delicious burger you're about to devour. But, according to The Los Angeles Times, if you’re grabbing lunch at McD’s, or any number of other fast-food joints, you’re probably getting a healthy serving of MCC (microcrystalline cellulose), a.k.a. wood pulp. Now, before you denounce the occasional Big Mac, here’s a crash course in what cellulose actually is and what it does.
Made up of oxygen, hydrogen, and carbon, cellulose is actually the most abundant organic compound on earth — it’s more commonly referred to as a dietary fiber. You can find it naturally in virtually all fruits and vegetables. Cellulose also shows up in foods as an additional “filler” ingredient. It's often used to thicken ice creams, to keep powdered drinks from absorbing unwanted moisture, or to stand in for another ingredient that would add calories where there were already plenty. That’s the appeal of adding cellulose to something like a burger. Because it’s both indigestible and has no real nutritional value, it can be added to the mix without compromising taste.