Yep, most are on one large mouse every 14 days. However I have a couple of males who run to fat even on that. They either get one large mouse every 21 days or sometimes 1 small mouse a fortnight if it's more convenient for my feeding schedule.
It's certainly much easier to get muscle back on a thin snake, than it is to get flab off an overweight snake. I prefer mine on the lean side for that reason. Because Corns are evolved to go without food for weeks and months at a time, it's very unlikely that a conscientious owner would starve a Corn with any kind of monitored feeding regime. Whilst I wouldn't do it, I knew one long-time Corn keeper who fed his adult males and non-breeding females one large mouse a month - I honestly couldn't see anything wrong with the snakes. They were all a decent size, were alert and healthy, had good muscle tone and were clearly nowhere near starving.
With fuzzies, I feed one ever 6-7 days. Don't be too keen to move him up a size if he's only just switched. It's better to have them grow slowly - in my experience they seem less likely to run to fat as adults if they do that.
