Even as a dietitian, my head starts spinning a little when I venture down the supplement aisle. There are so many options, and it's understandable to feel a little overwhelmed with dozens of brands staring back at you. And although protein shakes always have an air of healthiness, don't let them fool you. When it comes to picking the best protein shake for weight loss, I recommend using a few quick criteria to evaluate a high-quality protein shake: added sugar and artificial sweeteners, easy to digest, and complete protein.…