Delete word and preceding whitespace

When I edit a text, I often find myself removing one word from an existing sentence. I use diw for this, the problem is only, between the surrounding words of the just deleted word will remain two whitespaces, the one before and the one after the just deleted word. Is there an easy trick to remove a word and all preceding whitespaces?

I want to achieve this:

This is just an example

to

This is an example

With diw I am always left with

This is  an example

Maybe there is a cool trick I haven't found yet!