Though I usually fly across the Atlantic via AMS, I think the meals in Y are pretty much the same no matter where you depart from. And they can best be described as the least expensive stuff that DL could possibly serve and still call it food.

Small salad, usually choice of chicken (small piece in some sort of sauce, with rice and maybe a few vegetables) or pasta (vegetarian meal, tomato sauce with penne and maybe a few vegetables in the sauce), a stale dinner roll wrapped in plastic, a piece of cheese and 2 crackers, and a small dessert.

Second meal (snack), about 1.5 hours prior to landing, usually is a piece of pizza in a cardboard box and a cup of ice cream.

Alcoholic beverages (beer and wine) are included, but they are really stingy with them. One before dinner, one with dinner, and one with the snack. If you want anything else besides water to drink, you have to go to the galley and hopefully find someone there to get you a drink. Hard liquor and the signature cocktails are for purchase only. While the wine is free, don't be surprised when they pour it from a cardboard box instead of a bottle!

"Will it be terrible?"....well, that depends on your expectations. When I do fly in Y, I find the main meals acceptable but not great, and even find the pizza quite good, but would be happier with a bigger piece of it. But none of it is "exciting" and something to look forward to. I always bring a bag of cookies or some other snack with me to fill in between the two meals.