Changing cat food & calories

My fiancee and I are in the process of slowly switching her cats (3) over from Iams weight control dry to Innova dry. The cats are currently eating about a 50/50 blend of each food and should be 100% on Innova within a week or so. My concern is the change in calories, since Iams has about 346 and Innova has 537 per cup. The cats are fed 100% dry food and the food is available to them at all times. Do I need to worry about the cats gaining weight or will they be able to maintain their current weight by simply eating less of the higher calorie food? 2 of the 3 cats are in great shape and 1 is slightly overweight. Thanks!

You may need to cut back on potions if the Iams kept there wt proper... but likely you wont since Innova ( I presume EVO ) has far more fat and protein both are easier for a cat to digest

Thanks, sharky! The food is actually regular Innova dry, not the EVO. The problem we have with cutting back is that one of the cats tends to back down and not eat when the other 2 are eating. We're afraid he's not going to get his share. We weighed all the cats before beginning the switch, so we should be able to see what effect the food is having on them.

If you find that their weights do change, you may have to switch to meal feeding them. My hefty boy, Odo, gets 2 meals per day (today we find out if his diet works too). Willow, however, is a snacker, so I put her food up high where he can't reach it. That way, she can be free fed without Odo getting into the food (unless I forget and leave a chair next to the dresser--then he jumps up and chows down).