@3crazycats - Royal Canin dry food is not a good diet, it is high in carbohydrates and that is why your cat is overweight. Vets who recommend this food often do so because they sell the stuff! (excuse my cynicism, lol)
Even the RC Satiety is too high in carbs to be healthy for a cat.
I agree with OS, switch your cat to a wet food diet, no dry food at all.
Cats are obligate carnivores, so they need a diet high in meat protein. A feral cat eating natural prey would have an average daily energy intake of less than 2% carbohydrate, 52% crude protein, and 46% crude fat. Commercial feline dry food diets have up to 60% of their energy provided from carbohydrates!
Compared with dogs and humans, cats have a reduced capacity to metabolise high glucose intake, resulting in higher blood glucose concentrations after eating carbohydrates.
While cats do have some metabolic flexibility in processing carbohydrates provided their minimum protein requirements are met, glucose metabolism in cats is unique, resulting in a comparative carbohydrate intolerance.,
There is a pinned thread one of our members has kindly posted for us, giving the carb content of all the good quality grain free foods sold at Zooplus. Choose grain free wet foods that are no more than 7% carbs.
https://www.petforums.co.uk/threads...o.uk/threads/zooplus-cat-food-list-just-the-good-stuff-work-in-progress.440844/
Lisa Pierson, veterinarian and feline nutrition expert has very useful advice on healthy diet and on implementing a safe weight loss programme using wet foods.
https://catinfo.org/feline-obesity-an-epidemic-of-fat-cats/
https://catinfo.org/feline-obesity-an-epidemic-of-fat-cats/#Implementing_a_Safe_Weight-Loss_Program
As you will read Dr Pierson stresses the importance of slow and gradual weight loss, particularly when the cat is overweight. This is to avoid the risk of Liver Lipidosis, a nasty disease that can be life threatening.
Weight loss should be no more than about 50 grams (a couple of ounces) each week. Weigh your cat every week on digital scales and keep a record. This will tell you if you are feeding too little or too much. Do not feed the cat according to the eventual target weight - feed for the weight the cat is now, but with the aim of reducing the weight by 50 grams a week.