First of all, you need to understand that being obese is dangerous for the cat. If you think your fat kitty looks cute, think about how you would feel if the kitty's heart failed and you lost him / her.

Now that you want to help the kitty lose weight, here are two simple steps:

1) Regulated feedings.
2) Exercise.

With #1, it is really up to you how much you feed the cat, isn't it? Yes, I know that the kitty will beg for food, but you must be firm if you want to help him/her. Do not radically reduce the amount of food you give your cat, do it gradually. Look up the feeding directions on the cat food you buy, the manufacturer will tell you how much you need to give per day depending on the cat's weight. Split this amount into 3 equal servings and give them to the cat in the morning, in the middle of the day, and in the evening. If that is not often enough and the kitty keeps asking for more, split the recommended amount in 4 servings and have four smaller feedings a day. Self-feeding, with food available to the cat 24 hours a day, is out of the question.

Another thing you might consider is switching to weight control cat food that contains less calories. IAMS has a good cat food that is both Weight and Hairball control. With this type of food, you will be able to ease the transition to regulated feedings. You will be able to allow the cat to eat a little bit more. Your kitty cat will consume less calories without even knowing.

As to #2, cats love to play, which helps your purpose. Playing is the easiest way to get them move around and exercise. Even the laziest ones can be interested in a paper ball, string, or a lazer pointer. Some people think that cats lose interest in playing as they get older; they don't. You just need to find a good interactive toy. It does not have to be something fancy and expensive; usually, improvised homemade toys like a shoe string work best. My 7 year old cat loves chasing strings, he will play with them as long as I keep pulling on the other end, and sometimes even after that.

An important thing to remember with kitty exercise is not to overdo it, especially when you start. Begin with just a few minutes of simple exercise, then gradually increase the time and intensity of the playing sessions.