Food coma refers to the feeling of listlessness, bordering on sleep, that one feels after eating a large meal, often caused by a rush of blood to the stomach and intestines during food digestion.
“饭气攻心”指的是在大吃一顿后感到的困倦，通常是因为在食物消化过程中血液大量涌向胃的缘故。
Example:
I ate the whole pizza and now I'm slipping into a food coma.