Fat Cat

 A friend came to visit yesterday, she now lives out of the area. She's a huge cat lover and got to see everyone but Oliver and Billy. (Billy hid behind the sofa .. Oliver went out as he always does!) Anyway she was horrified to see Jamie and let us know in no uncertain terms. I know, I see it, but what can I do? He has less food than everyone else, and to be honest he doesn't always finish it. He never gets treats and my routine changed years ago so he doesn't steal dog food. He never comes for walks anymore like he use to, what am I suppose to do put a lead on him and drag him round the block?
There's no doubt Jamie is a lazy cat .. but he's also a laid back character .. nothing bothers him. He's chilled and relaxed, so maybe he has an equally slow metabolism?  If he's out he won't even move for a car driving onto the property, you go round him or you get out and move him. If he lived in a town, or even in the village he'd probably have been run over or stolen by now. (He also goes into people's vehicles)
I did ask the vet for advice, I asked about checking his thyroid but they felt it was unnecessary. I do agree at 6.7kg he is very over weight, in comparison Tia is 3.4kg and a little underweight. I suppose he should be about 5kg. Again I ask,What can I do? (Rhetorical question - answers on a post card are not necessary) If he was a dog I'd increase his exercise, but he's not and cats simply don't have the same rules in life. I've never had a fat cat before, but neither have I had such a sweet loving character of a cat either so maybe the derogatory remarks, though not unfounded do hurt a little.