Overweight/Obese

I need help with this topic. We follow the "free feed" method since we have 7 cats in the house right now (1 likes the garage better, the other hasn't been around for awhile) Some of these babies are completely at normal weight, and 2 of them we are having problems with. One would be Onyx he was a stray but isn't that badly overweight. Mittens was a feral when we got him as a baby, it has taken him 6 years to let us touch him without him trying to bite, he is now 8 years old and ever since we got him he has had a weight issue. When we took him to the vet they just said that it is nearly impossible to put a cat on a diet when you live in a multi-cat household. I know this can be done, it was just way to hard to even try when my mom was at work until 3 and then school from 4:30 to 10:30 pm, and I was at school. Now that I have graduated I have a whole lot more time to work on this, he has lived outside his whole life until this winter, when we carried him inside as to keep him warm and safe. He has now decided he likes it inside and around people, I have noticed he is finally losing weight, not much but it is something. I would like to put him on a diet to get him nice and healthy so he can have a better quality of life. I just don't know how to do it when we have the others to feed as well. We feed dry food only, wet for a treat once a month. I have heard many different things, one would be to feed a teaspoon of food every 3 hours. So maybe someone can help me since I know there are many multi-cat households!
Sorry this is so long!!!

Ok I had a break through, I just realized something that is going to make this all soooooo much easier. All but two of the cats come in my room to eat out of that food dish since to them it is "better". And only two of my cats need to lose weight, guess which two?? Yep, the ones that don't go into my room. So I will just get rid of the bowl in the kitchen where those two eat, and let the rest eat normal in my room. I will just feed the other two, Onyx and Mittens, seperately!! Yay, I am so glad I thought of this, I would still appreciate any comments or advice from anyone.

Anyone have any idea how much I should feed to help them lose weight? I went on one site and it said 3/4 cup, I found a food that I will feed the two of them, but it isn't on the companies web site, and that site said to feed like 1 1/4 cups of food!!!!! I haven't bought the food yet so I can't read the back of it....does 3/4 cup sound right?

There is no broad feeding guideline to lose weight. One cup of one cat food might have more/less calories than one cup of another cat food. Most have feeding charts on the back of the bag, but, if it's not a light formula the amount of calories in the feeding guide will not help your cat lose weight.

My vet suggested that I use the feeding guidelines on the package, but feed for the weight my cat should be, not what she is... so... if my cat is 13pds, and she should be 10pds, I should feed her like a 10 pound cat. You should most likely call your vet and see what they think you should do.

Try using a reduced calorie food, ones I like are Natural Balance reduced calorie and Nutro Natural Choice.