. I ended up with Friskies Supreme Supper (? think that's what it was called), but ended up switching to the Mixed Grill when that was d/c'd. This was based on his particular needs, the fact that he strongly preferred pate (as opposed to something chunky), and that I am totally broke. 
The cat in question is still growing in which case weight loss would be a problem. Growing cats need extra calories to sustain their growth and development. If you start a weight loss program now the poor cat will be malnourished and be stunted.I rescued a 30 lb cat and researched the best way to get a cat down to a decent weight, so have done a lot of research on wet foods (low carb is the way to go for weight reduction).
You want to look for something that's ideally not fish based (bad mercury issues=cancer etc.), as high in protein as possible and low in carbs. Low in potassium if your cat is elderly (to avoid renal disease), and, of course, low in calories if your cat is fat.
I copied a table (I can't remember the source... sorry, source!) and formatted it in Google sheets--here's the link. Hope you can sort: right now it is sorted by 1) highest protein; 2) lowest carbs; and 3) lowest potassium (but with no filters for max carbs/potassium, etc.), or eliminating fish entirely, which is why you see Tiki brands at the top (really high protein/low carb, but high potassium). I'm sure it has a lot of outdated brand info in it, but still could be a resource.
Hope you can sort/filter
Orijin used to be excellent food that most cats liked, but the stuff from the new US plant not only costs more per pound, but it is much lower quality, and has a lot of reports of cats hating it (mine wont' eat it, certainly), and even of some of the food having bad batches. Given the high prices, it just doesn't make much sense to use the new junk, IMO.
You're right. It's virtually impossible to make a dry food without starch from somewhere (grains/pototoes/pulses/veggies). The only truly low starch dry foods are freeze dried.
