KB Article: http://support.microsoft.com/kb/224663INTRODUCTIONWhen you save a Microsoft Word document that contains an EMF, PNG, GIF, or JPEG graphic as a different file format (for example, Word 6.0/95 (*.doc) or Rich Text Format (*.rtf)), the file size of the document may dramatically increase.
For example, a Microsoft Word 2000 document that contains a JPEG graphic that is saved as a Word 2000 document may have a file size of 45,568 bytes (44.5KB). However, when you save this file as Word 6.0/95 (*.doc) or as Rich Text Format (*.rtf) , the file size may grow to 1,289,728 bytes (1.22MB).
I'm familiar with this problem under Word 2007 and earlier versions, and I know of the registry change required to overcome it.
Today I had this issue with Word 2010 when converting a file to RTF. Although the support page at the top of this article doesn't include Word 2010 in the list of products affected by this problem, I decided to run the Fixit tool on that page. It appears to have resolved the issue. So thanks for making the tool available.
The same problem in Office 2013. For today it's not resolved.