Breakfast is a Human meal that is often consumed as the first food taken at the start of the day. By the 24th century, breakfast is still eaten as the start of a new day.
While serving together aboard the USS Enterprise-D and USS Enterprise-E, Captain Jean-Luc Picard and Doctor Beverly Crusher often had breakfast together to discuss issues of the day, and for general chatter. (TNG episodes: "The Perfect Mate", "The Chase", "Attached")
While being interviewed by Jake Sisko in 2389, Elim Garak offered the reporter breakfast consisting of scones and jam. (ST website: The Path to 2409)