According to Euromonitor, the meat substitutes market in the U.S. will grow to $2.5 billion by 2023. A similar study by Nielsen states that 98% of buyers of meat substitutes in the next five years will be flexitarians and meat-eaters looking to reduce their meat intake.

Demand for meat alternatives is undoubtedly on the rise. Even fast-food chains have started introducing new items to cash in on the latest trend.

In this context, Burger King's new plant-based burger is creating some controversy for the wrong reasons. Vegetarians are wary of trying it because, well, it is not totally vegetarian.

The meatless burger is made out of a plant-based protein mix that includes soy protein, coconut oil, potato protein, sunflower oil, yeast, salt, and a variety of emulsifying agents. It is attractive not just to vegetarians and to all consumers who demand more sustainably made goods.

However, the fact that the flame-grilled Impossible Whoppers are cooked on the same grill as beef and chicken products has not gone down well with vegetarians. The possibility of the burger coming into contact with bits of meat and poultry as it cooks is very likely.

Vegans are wary for a good reason. However, Burger King has assured the masses that customers can request that their meatless burger be cooked separately.

Burger King is not the only big chain to introduce meatless fast food options. White Castle, Subway and McDonald's have done the same, or plan to.

McDonald's plans to add a vegetarian-friendly burger to its menu in order to boost traffic. It could also be an attempt to offset the mounting pressure from its rivals who are adding plant-based options to their menus.

However, the Golden Arches are not in a rush like their counterparts. For McDonald’s, it’s more of a “wait and watch” approach to see if meatless is just a passing trend. While pondering, Burger King swooped it to test the Impossible Whopper.

Subway, which has been struggling in recent years, has partnered with Beyond Meat in the hopes of reviving its profits. Its plant-based meatball marinara sub is one of the first meat replacement offerings on its menu. The limited-time sandwich will be available in the U.S. and Canada.

Beyond Meat's sales are soaring due to restaurant sales and partnerships with chains like Del Taco, Tim Hortons, Dunkin', and Subway, among others. Investor and consumer enthusiasm about the growth of vegan meat alternatives paint a rosy picture for the company.

Interestingly enough, both Tim Hortons and Dunkin' Donuts cook their vegan sandwiches separately from their meat items. The former declared that it also stores its meatless items separately, ensuring that there is no cross-contamination.

Dunkin' locations that have the Beyond Meat sausage sandwich ensure that it is cooked separately on individual pieces of parchment paper. It also follows strict storage processes to store the patties on separate and individual portion trays.

Perhaps it is easier to separate meat from non-meat when restaurants use convection ovens or similar appliances instead of the broilers that Burger King uses. But in order to cater to all vegan and vegetarian consumers, it may have to come up with a solution soon.