My cat had lost some weight and we went to the vet to know what was wrong with her. The vet said it was nothing and it was probably stress. We moved houses a year ago and got a new kitten. The older cat is nine and this is the first time she got to go outside. The kitten was eating her food so i kept them seperate in the evening so she could finish her food. It went really well actually, when we started with new food she was 3,3 kilos and she got up to 4 kilos. The problem is, every time i leave for a couple of days she loses weight again. My family who feeds them don't wait until she is done eating and don't give her the special food (i don't want my younger cat to eat it because it has more fat in it and she has a good weight, and it's really expensive, so i keep it in a seperate bowl). Can it be because the younger cat eats it when they are not seperated while feeding? Sorry for the long post.