If you want to go cheaper, the Friskies pates are low carb enough for our sugarcats too. A few of their flavors have a tiny bit of rice, but its such a small amount that they still come in at under 10% carbs.
Along with restricting calories, you need to add exercise to Jack's daily regime (Awww mom!!....do I really have to do push-ups?....LOL)
Does he like chasing laser lights? My China didn't so I went through what seemed like $1000 trying to find something she would play with. Finally found
"Da Bird" that really drove her nuts. She'd chase that thing until she literally would have to stop to catch her breath (and they do need to be that tired to really do any good). If Jack is more driven to catching things on the ground, I highly recommend
The Ground prey wand. The "prey" jerks and jumps along the floor making a motion most cat's cant resist.
You can even go really cheap! I know one person who just attached a string to her shoe and her cat chased her around the house all day and another who tossed a tiny treat to the bottom of a staircase and her cat would race down the stairs to get it, then race back up to get another treat.
Anyway, just like human weight loss, it's never just counting calories....you have to burn some too!
If you can find a baby scale, they're great for keeping track of your progress. I bought
this one but you can sometimes find them for good prices at yard sales that have baby supplies. I could either put a towel down on it for her so she felt more secure or the best trick was putting it on the floor with a box on top.....cat gets into box, and BINGO, you've got a weight!
Weigh once a week and hopefully Jack will be able to fit into those tight jeans again....you know the ones.....that make his bootie look so cute?.....LOL