I watched this movie when I was young on the Sci-Fi network. It might have been made in the early 90's, late 80's. This movie was not an anime or animation, it had real actors. I think it might have been a trilogy.
Its main character was an obese women captured(?) along with a bunch of other people and she was sent to a RM on a metal table that made her thin and beautiful. She also teamed up with a robot head that fell in love with her (and was kinda pervy) and would unlock the doors for her to escape this place she had been captured.
I also remember there was a spaceship that had 12-8 brains that 'talked' and powered the space ship(?). The space ship and brains were important to the movie but I don't know why.
There were also these worm alien monsters that had been released in this futuristic gladiator arena.