My previous cat became obese he ate two large pouches (for two cats) plus dry food and tit-bits from us and at least one of our neighbours. The vet suggested we cut him down or he could end up with diabetes.
I cut him back to single pouches although I think he had the same amount but spread more evenly throughout the day. I felt mean as he was very agile and he didn't seem to have any adverse effects from being heavy.
Sometimes its cruel to be kind.
Sue