That being said I think the effect should be minor so its something people can choice to do, but they don't feel like to have to do it.
If they insist on having a food system this is how it should be.
Survival check to cook a special meal during a long rest that grants minor bonuses until the next short rest or some other time period, like...
+1d8 temporary HP (really good for level 1's) or +1 to Str and Con saves
