eat like a bird吃的像小鸟一样, 形容吃得很少、饭量小、饭量少, 胃和小鸟的一样。

【例句】
You eat like a bird – I don't know how you stay healthy.
你吃得太少了—我不知道你怎么能保持健康。

Girls always eat like a bird in order to keep a slender figure.
女孩子们吃的很少，为的是保持苗条的身材。