一口吃个胖子

一口吃个胖子:

Literally means:

build up constitution on one mouthful; try to build Rome in one day

Actually means:

It literally means trying to become a fat person with one single mouthful of food.

It figuratively describes lack of patience and seeking instant success out of haste. It is usually used in interrogative or negative form. Derogatory.

只吃一口饭就想变成一个大胖子。

比喻性急，想一下子取得才成功。没有耐心。多用疑问或否定形式。具有贬义色彩。