你真的很瘦。

Nǐ zhēn de hěn shòu.

You are really very thin.

你怎么吃那么多东西还是那么瘦？

Nǐ zěnme chī nàme duō dōngxi háishi nàme shòu?

How can you eat so much and still be so thin?

我妈妈也挺瘦的。

Wǒ māma yě tǐng shòu de.

My mother is also quite slim.