It's the shampoo we use in the shower. When I wash my hair, the shampoo runs down my whole body, and printed very clearly on the shampoo label is this warning , "FOR EXTRA VOLUME AND BODY." No wonder I have been gaining weight.
I am getting rid of the shampoo and am going to use dishwashing liquid instead. Its label reads, "DISSOLVES FAT THAT IS OTHERWISE DIFFICULT TO REMOVE." Problem solved.