Airline food is not something most passengers give much thought to, but the industry behind it is worth a mind-blowing $6 billion in the US.

Thousands of in-flight meals are produced per day, with catering companies working to meet demand from most major carriers. Meals are usually prepared in catering facilities close to the airport, and are later transported to the aircraft and placed in refrigerators for flight attendants to heat and serve on board.

Food is a key part of the flying experience, but today’s in-flight meals may not be as grand as they were a few decades ago. Airlines used to serve complimentary meals even on short flights. However, as costs increased and the competition became more intense, airlines had to cut down on in-flight meals to slash costs.

Who selects the menu items? Major airlines have culinary teams to curate their flight menus, which vary depending on the region, seat class, and season.

Airline meals are designed so that the food isn’t affected by changes in altitude and pressure, with extra sodium to ensure the taste doesn’t change. Airline chefs or catering groups usually provide instructions to the cabin crew on how to serve the meals for passengers to enjoy. With 2020 is expected to be a good year for airlines globally, the quality of airline food just might get better.