Mmmm. Wood pulp.
"McDonald's had the most menu items containing cellulose, with the wood-pulp additive present in shredded cheese, fish fillet patties, biscuits, sausage and scrambled egg mix, smoothie base, syrup, ice cream, barbecue sauce, sweet 'n' sour sauce and honey mustard sauce.
Quartz reported McDonald’s finished first, with 14 menu items containing cellulose. Burger King trailed closely behind with 13 menu items like buns, tortillas, tacos, onion rings, mozzarella sticks, pancakes and several others."
https://www.ibtimes.com/mcdonalds-burger-king-taco-bell-more-have-wood-pulp-food-1616514