I moved this into a new thread because I think you are referring to your current 3FC blog at diet-blogs/. If you log in and click the "manage" tab, you'll see an option to export. Export this file. I'm guessing you are using Wordpress for your new blog? If so, go to your new blog and choose to manage then import and upload the file you downloaded here. It's possible the location to import may be different since it's a different version of WP, but there will be an option to import somewhere in there. If you are using a different blogging platform on your new site, you'll need to check their support site to learn how to import a wordpress database.
I hope that helps