Possible Clues:

• One of a daily trio
• Substantial repast
• *Nutritious intake
• Scream with delight about a pop band -- decent fare?
• Complain when receiving a dose of radiation — a lot going into stomach?
• A corps caught in short spell of turbulence get proper food
• Ploughman's lunch, say, a group consumed in grass
• Nourishing repast
• It can still be served on a round plate!
• Healthy fare