It's my understanding that in heaven and the new earth, we will still be able to eat food. In heaven there's the marriage supper of the Lamb, and in the new earth I assume we'll live like we do here on earth but better and without pain, sin, death, etc.
We won't need food to survive but for pleasure because it is good. You might be thinking to yourself "we'll eat plants, fruits, and vegetables like in the garden of Eden", but then I ask, will we eat plants alive?
Will plants not die when we harvest them, cook them, eat them and digest them? Plants are just as much alive as we are and animals are.
>"He will wipe every tear from their eyes. There will be no more death' or mourning or crying or pain, for the old order of things has passed away." - Revelation 21:4
Notice the word "their", who is they? They are we, God's people. Not all life, not all of creation. Plants and animals don't go to heaven or hell after they die, they have no memories, no consciousness, no self awareness. Their lives aren't designed to be eternal like human's are, they don't worry about the afterlife. Could you imagine how overcrowded heaven would be if every animal that died went there? Every insect, every farm animal, even every plant.
I'm sure animals we kill in the new creation won't feel pain, maybe there'll be a new and instant way to kill them too, who knows. But what I do know is there will be food and that includes meat.
>"Everything that *lives and moves* about will be food for you. Just as I gave you the green plants, I now give you everything." - Genesis 9:3