To eat something up in English, you can say "to eat something up" or "to finish something off". For example, you can say "I ate the whole pizza up" or "I finished the whole pizza off".

These phrases likely come from the idea of completely consuming or finishing something, so there is nothing left. In Chinese, the common phrase for this is "吃光" or "吃完", which literally means to "eat until there is nothing left" or "eat until it is finished".

Here are some examples of "to eat something up" in English with Chinese translations:

I ate the whole cake up. 我把整个蛋糕吃光了。

She finished the bowl of noodles off. 她把一碗面吃完了。

He ate the entire box of chocolates up. 他把整个盒子巧克力吃光了。