New York (CNN Business) There's real demand for fake meat.

Interest in Impossible Foods' plant-based meat alternative is growing so much that the company is struggling to keep up, the company said Tuesday.

The acknowledgment comes just after the company expanded its partnership with Burger King. Earlier this week, the fast food chain shared that it plans to sell the meatless patty as a Whopper at all of its US locations by the end of the year. Restaurant Brands International, which owns Burger King, said a St. Louis test of the Impossible Whopper went "exceedingly well."

That nationwide rollout would essentially double the amount of restaurants that Impossible works with. Burger King had about 7,300 locations nationwide at the close of last year. Right now, Impossible supplies its product to about 7,000 restaurants.

On top of that, demand for Impossible products within those 7,000 locations has more than doubled, Impossible Foods CFO David Lee told CNN Business.

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