The fast-food industry has fallen in love with plant-based "meats" and the boost in foot traffic and sales they provide from more health- and climate-conscious consumers.Why it matters: The public’s growing interest in plant-based "meat" has start-ups trying to scale up and expand their market share, and food giants, such as Tyson Foods, are trying to muscle—and cash—in. The plant-based meat industry has seen $12.6 billion in sales and $4.5 billion in revenue as of July 2019, according to the Plant Based Food Association, and such non-meat burgers were estimated to be in 7,200 Burger Kings, 1,000 Carl's Jrs., and hundreds of other fast-food joints at the close of 2019.The state of play: Zak Weston, a foodservice analyst at The Good Food Institute, says both businesses benefit when fast-food chains partner with plant-based "meat" companies, such as start-up Impossible Foods and Lightlife Foods, which is operated by Canadian company Maple Leaf Foods. Every time a new partnership is announced, the chain and plant-based company see a rise in their stock prices, per Weston.Plant-based meats have a 3.5% market in American quick service restaurants. Burger King has capitalized on the plant-based "meat" trend following the release of its Impossible Whooper. The stores saw an overall increase in foot-traffic and a 3.5% sales increase in its U.S. stores, CNBC reports.Dave and Buster's restaurants switched from using Impossible Foods products for its burgers to Lightlife's plant-based patty as it gained popularity — highlighting an increase in market competition, Reuters reports. Food giants have entered the growing market — posing a challenge to startups centered around plant-based meats, the Washington Post notes. The larger companies already have systems in place to handle national production and distribution, areas where startups have struggled to meet growing demand, CNBC reports.Tyson announced the launch of its plant-based nuggets and a burger blended with beef and peas in July through its company Raised & Rooted. Beyond Meat stocks fell the day Tyson revealed its plant-based products, per the Post.Nestlé launched a plant-based patty in the fall, per CNBC. Nestlé CEO Mark Schneider told Fortune it took the company only 18 months to get a plant-based product on the shelves after they decided to enter the market.Why now? Weston says companies selling vegan or vegetarian items previously targeted a niche audience, but are now producing and marketing their items to the general public as healthy alternatives that taste just like meat.Worth noting: Ricardo San Martin, who studies meat alternatives at UC-Berkeley, told Vox, "plant-based means it’s of ingredients that come from plants...they are processed foods." In regards to climate change, meat production accounts for 8% of the greenhouse gases emitted in the U.S., the New York Times reports. Yes, but: While plant-based "meat" products have a smaller carbon footprint than animal meat products, they have five times the footprint of a bean patty, Marco Springmann, a senior environmental researcher at the University of Oxford, told CNBC. Go deeper: The fake meat gold rushPlant-based meat is ultra-processed, but consumers can't get enough