Withholding food for the purpose of trapping or surgery is necessary. It's not neessary, though, to withhold food to socialize. I have 5 rescued cats and I keep dry fod out 24/7 in addition to their special canned food, and they are all healthy. They play with their toys and each other, also with me with a laser and wand toy, so they get exercise. They don't over-eat or gorge themselves because they know that food is always available and not an issue. Cats who have been raised as young kittens indoors don't have the same issues as former feral cats or strays who have experienced hunger or starvation, so I am giving my perspective based on my experience socializing cats with these issues. Trust can be earned through play time and giving special food and treats. We can agree to disagree on this subject, each cat is different and I trust that each caregiver knows what is in the best interest of their special Kitty.