cheat meal
n.— «By setting aside one day a week to eat junk food or whatever you want you take control of your cravings and eat on your terms. This is often referred to as a “cheat meal” because you are deliberately cheating on you diet. This is a method of rewarding yourself for eating well during the rest of the week and provides a much needed psychological boost.» —“Behavioral Conditioning” FamousAndRich.com Apr. 17, 2009. (source: Double-Tongued Dictionary)
Further reading
If someone’s got melon, it means they’re smart. The expression most likely arose because of the resemblance between a melon and a human head. Several other foods are associated with having brains, including a cabbage, a gourd, and even a...