Your body is under attack --- by the food you eat.
There is a very interesting article over at WeLikeItRaw. It points to research done in 1930, that finds cooked food lets our bodies defence system react as if it needs to fend off an attack increasing the all over stress level. My preliminary conclusion (of course 100% unscientific <g>): Unless we can offset that stress through an appropriate setting (nice dinner, lustful food, friends, good mood etc) better stick to raw food. So no more midnight pizza or candy bars when hacking away in the night. Rather stick to apples and carrot sticks.