Thank you so much for all the helpful replies.

My cat is a lovely ginger and white moggy. It was actually the vet who told me he was overweight, and he wants me to take him back in a month or so to reassess, after trying to get his weight down by cutting down on food, so I think it is just that he has been overeating rather than anything more serious. Fingers crossed, anyway. My cat is really quite long, but he does have a largish belly that hangs down a little. Looking from above he just seems straight, rather than having a defined waist, but his weight is on the back end, rather than around the face and neck..

I have tried cutting out dried food altogether, and have bought Hi-life and Encore, which he refuses to eat, Applaws, which he ate then threw up straight away (maybe he gobbled it too quickly, greedy boy), and I've just bought some Nature's menu, so we'll see how that goes. I did consider Royal Canin wet, but that has "derivatives",which rules that out. Likewise, he doesn't have anything like Felix, Whiskas, etc. The only wet food he really likes is Feline Fayre, which I'm happy to buy as it has at least 50% real meat/fish content. He won't eat that on its own, though, and really prefers dry, which I have now cut right down. It's hard, though, when he eats the litle bit of dry and leaves the wet, as I don't want him to then be eating too little.

I also haven't ruled out a raw diet, but I haven't done enough research into it yet.

He gets an occasional treat from a packet of cat treats, or a piece of raw chicken, and a very occasional sneaky lick of an empty porridge bowl, but he has nothing cooked from our plates, and he never tries to scave anything.

He does have a couple of scratching posts, as well as lots of toys, and has a few daily playtime rituals with us, so he does get quite a lot of play. The cat treadmill sounds a fantastic idea - I'm sure someone could make a fortune with that!!

Thanks again for your help!