PDF modified file size

I tested your PDF24 Creator in italian to modify the fields Author, Title, Subject and Keyword of an exsisting PDF file ver.1.4, but your software increased the file size of an amount of 20/30%. Can You explain to me why It happens? Thanks. Alessandro AB_56729@YAHOO.IT

I modified the fields reported above leaving all the others PDF file settings to standard and the file size increased from 997KB to 1,23MB. What do your software added to the file? Thanks. Alessandro AB_56729@YAHOO.IT

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