Prandial: Of or relating to a meal. Prandial pain is pain while eating.
Although medical terms usually have a reasonably logical derivation, this is not the case with "prandial." It comes from the Latin "prandium" which meant "a late breakfast or lunch." "Prandium" was derived in turn from the Greek "pro-", before + "endios", midday.
Now, however, "prandial" refers to any meal -- breakfast, lunch, supper or snack.