work up an appetite  引起食欲，胃口大增。例：

He worked up an appetite after a long day of chopping wood.

在砍了一天柴后，他食欲大增。

You need to work up an appetite first, then we'll go to the buffet.

你得先让自己饿得饥肠辘辘，然后我们再去吃自助餐。