To seek to impress others by feigning abilities or wealth beyond one's actual means; literally to slap one's own face until it is swollen to look like a fat man (who was traditionally seen as wealthy or imposing).

to want to get fat with only one mouthful; to try to achieve one's goal in the shortest time possible or expect results too quickly

literally "one cannot get fat with a single mouthful"; used as a proverb to mean that nothing significant can be accomplished in a single effort or that any great achievement requires time and persistence

a person who is short and heavy; an endomorph