ST. LOUIS – What’s the hottest trend in fast food? As unlikely as it seems, it’s vegetables, Business Insider reports. “We're going to see more vegetables, said Dan Kish, head chef at Panera. He pointed out that the fast-casual chain is trying to balance meaty menu items with more veggies.

“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,” Kish said. “Upping the percentage of vegetables in your diet—[it] is part of our job to help you with that.”

With its emphasis on customization, Taco Bell allows nearly any dish to be made meatless. In 2015, the Mexican chain launched a vegetarian menu that lets customers swap meat for beans and rice. “Vegetarian has been really big for us recently,” mostly because of the push by millennials, said Missy Nelson, the fast-food chain’s dietitian and product developer.

Other chains are embracing vegetables too by branching out beyond tomatoes and iceberg lettuce. For example, Chick-fil-A and McDonald’s have started testing broccolini and kale in menu items. “They didn't feel iceberg lettuce was a nutritious green, and they didn't feel good about eating it in a salad,” said Jessica Foust, corporate chef for McDonald’s.

Consumer demand is driving these changes, as more Americans slash meat consumption. Plus, more veggies on the menu also appeals to the average consumer, who wants to eat more plants. In addition, vegetables cost less than meat, which is good for the restaurant’s bottom line.