My cat weighs twenty pounds

So, recently we've become worried over our cats' weight. We leave out food so that all three can help themselves, and two of the three overeat -- so much so that we decided to take them to the vet and get them weighed. It turns out Hastur, our middle cat, weighed 16.4 pounds. Accordingly, we got some prescription weight-loss food for her, which fortunately she turns out to prefer to the regular stuff. When I took her back about two months later, she was at 16.2 pounds, so looks like she's moving in the right direction.
Of course, this made me decided it was time that Feanor, the youngest of the three, got his turn, so in he went in April. I was amazed to discover that he weighs 20.8 pounds. The late lamented Parker, whom people often said "now that's a big cat" when they saw him, was only about 15 pounds, so Feanor outweighs him by a goodish bit. Accordingly, the regular (dry) catfood now gets mixed with the 'lite' and 'prescription' stuff, since unfortunately he likes the higher-carb stuff best. We're hoping this gradually brings his weigh down as well. Several of our friends have senior cats whose weight problems have led to diabetes and other woes, and having so narrowly escaped that fate myself we're thinking the same solution might do our cats some good: bring down the weight now before the problems develop and get out of hand. Luckily they're still relatively young (Hastur is now almost six, Feanor about five and a half).
The trickiest part is that Rigby, who at almost ten is now our Senior Cat, weighs only about 8.5 pounds -- just the right size, though we keep imagining that she looks too thin when in fact it's the others who aren't thin enough. So we have to make sure she gets enough, despite her general lack of interest in food (she eats only when she's hungry), while keeping the others from eating too much. With luck, the others will be at a healthier weight by year's end, but it's going to be a slow process.
But then 45.5 pounds of cat is more than enough of a good thing.
--JDR
current reading: AN [ILLUSTRATED] AUTOBIOGRAPHY, by Anthony Trollope.