America's food supply chain has been turned upside down.

Before the arrival of the coronavirus, statistics website estimated that nearly half of all money Americans spent on food was spent at restaurants -- $0.48 out of each $1, to be precise. Now, however, all our restaurants are closed (or eking out a living doing takeout and delivery) while grocery store shelves are bare of everything from flour to frozen vegetables (to toilet paper, of course).  

Bags of groceries outside a home's door.

Image source: Getty Images.

If this turns into a long-term trend, America's going to have to significantly restructure its supply chains, routing more food to grocers, and less to restaurants. In the meantime, though, two restaurant chains are taking matters into their own hands, and starting up online "grocery stores" to reallocate their produce.

Panera Bread, the restaurant chain bought out by privately held JAB Holding in 2017, is one. On a new Panera Grocery webpage, it's advertising pickup or delivery service for customers who want to order items like bread ($4.49 a loaf), milk ($4.99 a gallon), avocados, and blueberries, in addition to its usual store-made meals.  

Subway is another. The privately owned sandwich chain now has its own Subway Grocery website up and running, where it appears to be holding a rummage sale on essentially everything it ordinarily loads onto its sandwiches in-store -- from bacon and grilled chicken breast to cheese, onions, pickles, and tomatoes, and the bread to layer them on.

Whether these online groceries turn out to be a stopgap measure that disappears along with COVID-19, or evolve into something more permanent, remains to be seen. For now, only one thing's for sure: You still can't buy flour, frozen veggies, or toilet paper at Panera -- or at Subway, either.