The extreme emotional let-down experienced when one has high expectations for a meal, and the meal turns out to be bad.
Sally: What's wrong?
Susie: I got a bad case of meal disappointment. I worked through lunch, and was starving after work so I stopped for Chinese food on the way home. It smelled so good in the car, but when I took a bite it was too salty. I was hungry so I ate it anyways, but I can't shake the meal disappointment.
Sally: That sucks.