Istanbul is such a compelling foodie destination that folks crave stopping in town on a longish layover at the airport. I don't blame them. Although we've found the food first-rate on Turkish Air, a journey into the culinary underbelly of Istanbul is always a treat.
Culinary Backroads has some suggestions on where to eat on a layover at Atatürk Airport without resorting to those dismal food courts airports offer. See: Ask the CB Network: Flyby Dining in Istanbul.