Whey protein consumed after a tough strength-training workout promotes lean muscle gain. Whey protein powder mixed into milk, juice or water also makes a filling snack that can help when you're trying to cut calories. Not all protein supplements are created equal, though. Some contain additives that lack scientific proof, or extra sugars or artificial sweeteners that don't promote optimal health. Always check the protein's packaging and nutrition label to help you make the healthiest choices.
When whey protein is subjected to high temperatures, the process negatively affects some of its essential amino acids. Cold-processed or raw whey protein powder is not subjected to heat during processing, and thus the amino acids are fully available, as are the whey protein's immune-boosting compounds and antioxidants. You'll find cold-processed whey primarily in powder form.
Whey from grass-fed cows hasn't been shown in studies to provide superior nutrition. Choosing it does prevent you from being exposed to products from cows that may have been treated with antibiotics and given feed containing pesticides or growth chemicals. Grass-fed whey is usually sold as a powder, though it is making its way into some supplemental bars.
Whey protein isolate is the most processed form of the product. It usually yields a product with only trace amounts of lactose and a higher protein content. During the processing, though, micronutrients and immune-boosting compounds are lost. Whey protein isolate also undergo acid processing, which denatures the amino acids, rendering them less useful to your body. If you're not seriously lactose-intolerant, whey protein concentrate is a superior option because it retains these essential nutrients.
Whey protein is a natural product, but it's often sweetened heavily to taste palatable. Many contain artificial sweeteners to keep the calorie and sugar count low. Ideally, you'll choose unsweetened powders and add your own sweeteners using fresh fruit, honey or maple syrup. If shopping for a whey protein bar, look for one with more protein grams than sugar grams and no high-fructose corn syrup.
In 2010, a Consumer Reports investigation revealed many name-brand protein shakes contained levels of heavy metals that exceeded allowances made by the nonprofit group United States Pharmacopoeia. These metals included arsenic, cadmium, lead and mercury. Your organs can be damaged by regular exposure to these metals. Look for shakes, powders and bars that are organic to help reduce your exposure.