I don't know WHY I didn't figure this out sooner. It's the shampoo I use in the shower!
When I wash my hair, the shampoo runs down my whole body.
Printed very clearly on the shampoo label is this warning, "FOR EXTRA VOLUME AND BODY."
No WONDER I have been gaining weight!
Well, I have got rid of that shampoo and I am going to start using Dish Washing Liquid instead.
It's label reads, "DISSOLVES FAT THAT IS OTHERWISE DIFFICULT TO REMOVE."