It's not just your imagination. Just about every fast-food chain, from McDonald's to Carl's Jr. to Burger King, is introducing more bacon items to their menus.

The number of restaurant menus across the U.S. that feature bacon has grown by 5% in the last 10 years. Bacon was found on 68.1% of fast-food menus in 2018, according to Datassential. By 2022, the number is expected to jump to 69.8% of menus.

The fatty meat has always been popular with consumers. A&W Restaurants, one of the oldest fast-food restaurants, claims to have invented the bacon cheeseburger all the way back in 1963. Dale Mulder, the restaurant's chairman, put the item on the menu after customers kept asking for bacon on top of their burger patties.

Over the last 15 years or so, the ingredient has fully made the switch from a breakfast staple to a food that U.S. consumers will eat at any time of day. Since then, it has become a go-to for restaurants to jazz up their dishes. Bacon bits can be found at supermarkets and on top of salads, while restaurants use whole slices of the fatty meat to wrap asparagus, pizza and every food in between.

Now fast-food chains are using bacon to lure customers through their doors without the hassle of real menu innovation. For example, Burger King added bacon to its cheesy tater tots as a way to add something new to the limited-time offer.

"It does seem like bacon is a way to change up the flavors," said Darren Seifer, a food and beverage analyst for The NPD Group.

In some cases, like Carl's Jr.'s bacon truffle-flavored burger and fries, bacon just works as a complement to other new flavors.

Fast-food favorites like McDonald's, Yum Brands' Taco Bell and Wendy's have had to raise prices to keep sales from declining as foot traffic across the industry falls. Bacon not only offers a way to lure customers back, it can also be used to justify higher prices for the value-focused consumer by emphasizing the amount of bacon — double or triple the usual serving.

"McDonald's is currently driving a great deal of excitement (and volume) around this popular ingredient," Charley Orwig, marketing director at Datassential, said in an email.

At the beginning of this year, McDonald's added bacon to its Big Mac and Quarter Pounder burgers and introduced cheesy bacon fries. Like many other fast-food chains adding more bacon to their lineup, McDonald's chose to offer the bacon-centric menu items for a limited time only.

Limited-time offerings can drive foot traffic and encourage customers to buy more than just the promoted item, so fast-food restaurants likely also see similar benefits, according to Seifer.

To get customers excited for its bacon additions, McDonald's held a "Bacon Hour" that gave away free bacon to customers with any order. Wendy's used the lure of a free Baconator cheeseburger to get customers to order their food through third-party delivery service DoorDash. All they had to do was spend $10 and they would score a free burger without a delivery fee.

The ironic part of bacon's popularity is that it comes as consumers are increasingly focused on health and wellness and are opting for low-calorie options or fewer processed foods. While packaged-food companies have tried to adapt by buying smaller, health-focused brands, changing consumer tastes has not stopped the fast-food industry from adding bacon, which contains high levels of saturated fat and has been linked to heart disease.

"Health at restaurants has a different meaning than what we think about when we think about health at home," Seifer said. "We're not looking for pure health when we go to quick-service restaurants."