Due to my parents always over packing and hoarding, which made me go insane when I was a kid, I always pack light. I prefer a more organized and efficient lifestyle so as a result I usually only pack enough food to satisfy myself, not extra. I usually just pack some meat to go on the fire, steak or chicken and some packets of crisps/sweets and flavored water. I don't camp in the wild like a complete cave man, I usually sleep right by my car/tent so I guess I have never been in a situation where I would need to get food from the environment. I'd prefer not getting in trouble as a result of taking something from the environment, e.g fishing, since laws here with regards to that are rather strict. So I stick with food I buy at the shop.
So to sum it up I usually eat the same/a little less, for the sake of keeping the luggage at a minimum, less unpacking and throwing away to do when I get home anyway.