The only thing my cats lost was their condition.
I put my four cats on this as two of them were overweight. They gobbled it up and I kept them on it for four months or so, they did not lose weight, despite me giving them exact recommended quantity each time (and nothing between) and it made all of them lose condition, their coats, once shiny, became dull and contained dandruff. One of my cats got very constipated and I had to take to the vet for a laxative. I do not recommend this product and I wish I had never bought it.