The breakfast sandwich is rapidly replacing cereal as the typical morning meal, reported the Washington Post.

According to David Portalatin, food industry advisor to research firm Circana, there are two major reasons for the rising trend in breakfast sandwich consumption. One is the portability of the sandwich, as more than ever, consumers want to be able to eat food on the go. Another reason is that now people are looking for more protein in the morning for a healthy start to the day.

“The breakfast sandwich has been a portable source of protein that is convenient and nutritious,” Portalatin told the Post. “That’s been the biggest change in breakfast in the last 10 years.”

This year, breakfast sandwiches were the fastest-growing item at QSRs and convenience stores, according to data from Circana. Additionally, the Post reports, sales are up in grocery and convenience stores. Americans spent more than $2.4 billion on breakfast sandwiches in the year ending in September, up from almost $1.5 billion in 2019, according to NielsenIQ.

Meanwhile, cereal, a previous American breakfast staple, has been declining for years, said the Post. A 2016 study showed that millennials were avoiding the meal because they couldn’t be bothered to wash the bowl and spoon. Since the pandemic, sales of cereal have fallen even further.

Eric Smith, a senior associate brand manager with Jimmy Dean who focuses on sandwiches, said that convenience is king.  “That’s the main driver of breakfast sandwiches, the overall ease,” Smith says. “Being able to take an item frozen—whether it’s getting in the car or bringing it to the office or school, and having it on the go—is the driver behind the success.”