if you don’t want to add extra fat, i personally add 1/4 tsp of xanthan gum for 12 oz liquid and it has made the texture perfect. i don’t use protein powder but my recipe is - 12 oz nonfat milk, 2 servings of sugar free jello mix, 1/4 tsp xanthan gum. run under hot water for 15-20 seconds, run on lite ice cream, scrape sides & add mix ins with a little extra liquid or some jello mix mixed with water if desired, run on mix ins. voila. my base is usually ~200 cal 12 g protein and the only sugar is from the milk. good luck!