(Taco Bell is one of the chain's leading the charge to provide more vegetarian fast-food options.Taco Bell)
Forget burritos and burgers — today, vegetables are the hottest trend in the fast-food industry.
Vegetables are exploding on the menus of fast-food and fast-casual chains, from greasy omnivore favorites like Taco Bell to new vegan concepts like By Chloe.
"We're going to see more vegetables," Panera's head chef Dan Kish told Business Insider.
"We're going to see culinary treatments of those vegetables in ways that bring out their flavors without adding a lot of other things to it — so keeping things as natural as possible. Upping the percentage of vegetables in your diet — [it] is part of our job to help you with that."
Ironically enough, Kish brought up the rise of vegetables at an event promoting the launch of the chain's new and improved bacon. However, in the modern chain-restaurant landscape, meat and vegetables are increasingly living in harmony on menus.
(While Panera isn't ditching meat, it is working to add more vegetables across the menu.Panera on Facebook)
Kish says that Panera is aiming to balance meat-centric options, like a bacon-turkey sandwich, by packing more vegetables into the dish.
On the other hand, Taco Bell, a chain hardly known for sustainability and nutrition in the way that Panera is, has a slightly different approach that's similarly packed with vegetables. The Mexican chain emphasizes customization, and customers' ability to make almost any dish meat-free. Last year, Taco Bell debuted a vegetarian menu certified by the American Vegetarian Association, which allows customers to substitute beans and rice for meat in most menu offerings.
"Vegetarian has been really big for us recently," because of its relevance to millennials, Taco Bell's dietitian and product developer, Missy Nelson, told Business Insider earlier this year.
Even less vegetarian-friendly chains are realizing that vegetables may be key to success. While once iceberg lettuce and tired tomatoes were accepted as a forgettable garnish at chain restaurants, meat-centric chains are doubling down on veggie quality.
(McDonald's new salad blend is iceberg-lettuce free.McDonald's)
Both Chick-fil-A and McDonald's have ditched iceberg lettuce in recent years. Instead, the chains are testing vegetables such as kale and broccolini.
"They didn't feel iceberg lettuce was a nutritious green, and they didn't feel good about eating it in a salad," McDonald's corporate chef Jessica Foust told Business Insider in July.
Why are fast-food chains investing in vegetables, something that has long been seen as antithetical to their existence?