My 2 cats eat a combo Wellness Core Indoor wet and dry.  I'm thinking of switching to total canned, for weight loss.  Wellness only has 11% protein and a few sites have recommended 35-45%!!  any good sites to help "wade" through this?  Thanks

Wellness is pretty high in protein. The guartanteed max/min nutrition info on the labels are useless. Here's a chart that lists the exact nutritional content in a variety of canned foods: http://catinfo.org/docs/FoodChartPublic9-22-12.pdf For safe weight loss tips, see http://catinfo.org/?link=felineobesity You generally want to feed about 10 to 20 calories per pound of ideal body weight but some overweight cats may need to do a very gradual slow reduction in calories to avoid fatty liver disease.

The suggestions you're seeing are based on dry food or dry matter basis. Bear in mind that canned food is usually around 78%+ water, so that already takes a LOT of the percentage, so to find the accurate minimum protein percentage, you'll have to remove the water from your food by calculating its dry matter:

How to Compare Cat Foods & Calculate Carbs: Dry Matter Basis