Learn English – the antonym of “outgrow”

antonymssingle-word-requests

It's easy to say that you outgrew your clothes, but what's the word to indicate the opposite?

I lost so much weight that I _ _ _ _ _ my belt!

There is no single word antonym in that situation (at least, none I am aware of).

The idiomatic phrase to use would be:

I lost so much weight that I had to tighten my belt!

or for another article of clothing, perhaps:

I lost so much weight that I had to take in my pants.