if you have a health food store nearby that has bins, you can also look for Textured Vegetable Protein or Soy Protein Isolate (also called soy powder). If it's in granules, you'd have to whir it in your food processor to turn it into something that will stick to chicken or fish. The Soy Powder is available from some of the on-line LC vendors, too, I believe.

A combination of soy flour (a different thing altogether from the above!) and nut flours (nuts whirred in your food processor) is much better IMO, but does have a few more carbs.

now....exact carb counts on all these? oops, don't have them at hand...but the protein/powder should be very very low.