What do airline pilots eat on a flight, and when?
1: Do pilots eat during flight or they wait until they are back on the ground?

As pilots happen to be humans, their metabolism works in a similar fashion as yours or mine work. So they eat when they are hungry. On a long flight, they can eat during the flight, but on short flights (e.g. 30 minutes - 2 hours), they might not get enough free time to have a meal.

On busy days, pilots may not get enough time to have proper meals, so they try to eat small meals containing more nutrition. This is detailed in an article on Airline Pilot Central. They also avoid heavy meals before a flight.

2: Do they get the same food that is served to the passengers or do they bring their own meal?

Most of the time, food served to the passengers is the same which is served to the pilots, although they don't eat the exact same food. An airline pilot revealed that:


  ... the pilot gets the first class meal and the copilot the business
  class meal.