Why does Pages, export to *.doc a file that is larger than expected? I authored a 1 page document of about 900 words, and an embedded image (a chart).  Storing/exporting this document from Pages 5.2 causes the file to expand to 1.6 MB in size.  However, opening and saving the same .doc file in MS Word gives me a file (.doc) of only 99 KB. Why is Pages so inefficient (some 16 times larger)?

Is there a way to force Pages to trim the size?  My best alternative is to open the same 1.6 MB file in MS Word, and then re-save (which gets it back to a sensible size).  But I would like to eliminate MS Word entirely, except for the *.doc, which my clients like.
There is a bug in Pages. When you export a file in ".doc" or ".docx" format it embeds 489KB PNG files (a single one in a docx file, three in a doc file). These files are intended to be used as the background fill on default shapes, but they are present whether they are used or not.

I documented the bug here.

And reported it to Apple as rdar://17089255.

At the moment the simplest solution is to open and close the file in another application like Microsoft Word or LibreOffice. They both strip out the unused PNG files.