One of my babies (2 dogs, 3 cats, all adopted/rescued from the streets, all sterile and all girls besides him) is a chonky kitty, he turned 1 a couple months ago. I took him to the vet when he was around 8 months, 2 months after his sterilisation surgery, because I was worried about his weight. I've always done free feeding because when I adopted them, they were all very traumatised and anxious about scarcity of food, and some were even traumatised due to being poisoned before. I thought i was doing the right thing to help them be mentally healthier. The vet told me I should wait until he was at least 1 year old before I got worried, because he needed to grow and diets could stunt his development.

Alright, I waited. I took him to the vet again, and the guy told me to just buy food for sterilised cats and give him the recommended amount written on the package according to his weight. I was kinda pissed.

Anyway, I've been looking at the guide, and truly all I want from you is to know if I fucked up by trusting this vet and if I should just find a new place to take my pets. Word of encouragement or tips are also very welcome.

Added context just in case: I've never had a problem with overweight animals, all of them were or still are picky eaters due to their traumas, so I've never had this type of interaction with this or any other vet before. I'm not very familiar with this type of issue, and I'm doing my very best, but I'm considering asking for professional help from a pet dietician in a neighbouring city because I really don't want to make a mistake and destroy my son's health in the process. He's around 7.5kg now (weighted him 4 days ago), his optimal weight would be around 5.5kg, and from what I can tell he looks like a "common European cat" (ginger baby with slightly larger head).