I did some testing... eating 1 meal i tried to do different things.
1) I went to the spider cave and looted it (spider queen included), then went to ziva's abbandoned hut and made fertility potions then run for the cemetary, MC got hungry after fighting the 2nd bandit
2) I bought the meal from the inn and wemt to the tower of dread, on the way back I stopped by frida's house to have some fun, then decided to go home. meal's effect wore off when returning to goblin forest.
in both tests, the MC was rested and ate 1 pumpkin before consuming the meal