The Allow Fast Save feature needs to be disabled. In other words, these are incremental saves of all the edits that you have carried out on the document. If Allow Fast Saves is ON and you pass on a file which has just been saved, you pass on a whole lot of mess. However, if you do a Save As, the program will rebuild the file as one neat whole. Save As is the solution to all Word bloat problems.
Word recreates the file and saves it again.
This gets rid of several problems which the file might have had. Word 2000 uses compression and therefore leaves enough space when it encounters an earlier version. This causes the Word 2000 file to bloat. To solve this problem, simply add a few words or even a few spaces and do a Save As. Your file should be the correct size now.