The blogs were upgraded to the latest version.
The blue admin bar at the top of the blogs was removed because it is not functioning properly with the latest version. I'm working on it, but it may be a couple of days before it works properly.
In the meantime, you can access your blog admin panel from the admin link on your blogs (usually in the menu to the side or bottom of your blog, depending on your theme) OR you can log in from the blog homepage or directly at http://3fatchicks.com/diet-blogs/wp-admin/
If you experience any errors or notice anything goofy, please PM me with a link and details.