Soy protein is processed from the soybean plant. Most of the fat, fiber and carbs are then removed. It's a vegetarian source of protein and is cholesterol free. The FDA has approved a health claim for soy protein as follows: "25 grams of soy protein daily in a diet low in saturated fat and cholesterol may reduce the risk of heart disease."

Soy protein's high isoflavone or phytoestrogen content may also temper symptoms of menopause in middle-aged women. It may help with normal thyroid function to keep your metabolism steady. And soy is high in the amino acid glutamine, which is particulary good news for runners and endurance athletes.

Soy is either from GMO or non-GMO soybeans. GMO means Genetically Modified Organism. Expect to pay slightly more to buy a non-GMO soy protein, meaning the soybean plant has not had any of its genes altered in order to improve crop yields.