change in body with kitten to cat food.....

At first I thought is was just Tacoma losing weight, but then Tundra started dropping as well.
Do cats generally lose a little weight when you switch from Kitten to Adult Cat food? I still mix the dry food with wet Nutro twice a day and then free feed during the day. They both still eat about the same amount as before.
Just wondering if it was normal.....

Adult food typically has fewer calories per cup. If they are eating the same amount, they are not getting as many calories as before and will naturally lose weight.

Were they overweight at all?

No they weren't overweight to begin with but they def. were bigger than they are now. I also noticed that they go looking for their food bowls later on a night, every now and again I give them a little extra wet food.
Thanks for your response