If you can feed more canned and less (or no) dry that would be even better. Dry food isn't great for cats as explained in detail at Catinfo.org
Weight gain is caused by too many calories daily and little exercise. Dry foods tend to be very high in calories per cup which is why many dry fed only cats are overweight couch potatoes. Most canned foods are lower in calories per can (around 150 for a 5.5 oz can, and less than 100 for a 3 oz can). It's generally suggested to feed enough calories daily to keep the cat at a good body weight. 20 to 25 calories per pound of ideal body weight daily is often recommended but some cats may need more or less than that.