I ran into this issue once again and spent hours going through this forum trying to find a solution. The problem was bloated metadata which I have no idea how it happened. But instead of writing a step by step how-to, I made a video on Youtube showing how I was able to fix it. Someone posted a link in this forum to where I got the info from but it was really confusing to follow so hopefully this video will make it a quick and easy fix for you so you can get back to work. Good luck!
This is for those who have a photoshop file that's saving unusually large jpegs for no reason. I'm talking about jpegs that should be only 50-300kb but saving at 10-100mb. Full disclosure, I have no idea how this works and I don't really care, but the links under the Resources will provide more ...
The problem was bloated metadata which I have no idea how it happened.
photoshop:DocumentAncestors metadata is written to a file as a record of copy/paste or placed document ID entries.
It can naturally build up if templates are in use, as each time a new image is copy/pased or placed another line of metadata is added. This metadata is small in itself, however, it can build up. In "normal" use, this shouldn't be much of an issue. Unfortunately, for some users, this is a major issue.