Need advice on how to feed my cats.

I have 3 cats: Snowball is 15 and a good weight of 7-8 lbs. Spooky is 12 and way overweight at 17 lbs. (should be about 10 to maybe 12 lbs IMO). Mouse is probably 8 or 9 lbs., normal, but I don't want her to gain any. For most of their lives, I have free fed dry food. However, I have recently been told that my cats should be eating at least some canned and that the free feeding dry is why Spooky is overweight. The past few weeks I have given them each some canned in the morning and evening and left the low cal dry out only at night. Snowball cries constantly for food. Spooky seems to be getting fatter.

Can any of you cat experts recommend to me a feeding plan for these cats? I am pretty ignorant about this, so I need to know what variety I should feed each cat, times of day and how much. The only thing is that unfortunately I can't afford to go to a real high-end brand. I have been buying Iams, which I know is no longer considered top-of-the line, but right now it's the best I can afford. Thank you for any help I can get.

I honestly won't feed iams or support them anymore because of what they do to their animals: www.iamscruetly.com

wet food is best for getting cats to lose wieght, if you have a petsmart you can go to their wet and dry authority brands are decent food. though imo the more premuim brands cost less b/c the cats eat less and less waste comes out so you use a bit less food as well as litter.

petco has natural balance, wellness and wellness CORE. petsmart has blue wilderness and if you need cheaper authority.

other premuim brands (or i believe they are the best): EVO, Nature's Variety Instinct, Taste of the Wild, Before Grain, Kirkland, and Pinnicle.

But yes, wet food is best for weight loss. however low calorie food is worse for wieght loss because it has to many extra carbs. the more meat the better when it comes to wieght loss (and any other cat)

Canned IMHO is a good route for you ... you can do it on a shoe string budget... ie I found one with by products ( not a fav of mine unless I KNOW what it is ) but NO grain , artificial colors or flavors and it HAS a Natural vitamin supplement ... 22 oz can in my local stores is 1.09-1.33

IMHO purina naturals avail at the grocery or big box store is FAR better than iamd and cheaper at roughly a 1$ a lb

HAS a VET stated how much the "cubby" one should weigh ?? IF not it is best to ask before dieting a cat as it can be dangerous