Reducing the size of a document - optimizing does not help

Hello.

I am converting from a Word document with very simple charts and images (mostly screen shots). The document is 70 pages, and in the past, conversion took me to around 7 MB. Now, with the new version of Prof, the resulting file size is 21.7MB. Optimizing does not reduce the size even though I have it on the lowest quality setting.

How do I reduce the size?

Thanks,

Heidi