Evaluating Protein Powders
Kari Kennedy, RD, LDN
Many studies indicate that protein is extremely beneficial for weight loss and maintenance. The high carbohydrate low-fat and minimal protein diet once recommended by leading experts was one factor of many that has helped fuel an obesity epidemic. While decreasing total calories and carbohydrates is important, many people could benefit from increasing their protein intake up to about 30% of total calories, unless they have specific medical conditions such as kidney disease. While meat is one of the best sources of protein, many people are trying to decrease their meat intake and turning to protein powders for extra protein. Below is a quick overview of many of the protein powders available and their benefits and disadvantages.
Whey is one of the most popular and commonly used protein powders. Whey is a milk protein that is a complete protein and easily digested for most individuals. Many studies indicate it has therapeutic capabilities and may even help with diabetes. One study in the American Journal of Clinical Nutrition (Lacroix, et al., 2006) however did indicate that the amino acid delivery in whey is too fast to sustain muscle development directly after a meal. Basically this means this is not the supplement if you are intending to body build. Nevertheless, whey protein remains one of the best and most common protein supplements on the market. Casein, another milk protein, is another common option. Casein is absorbed slower than whey; however, it is generally not tolerated as well by individuals who are sensitive to milk proteins.
Egg protein powders are also available. Egg protein is easily digested, is a complete protein source, but like casein, is a common food allergen. Another side note about egg protein is that it is high in sulfur containing proteins, which has the unfortunate side effect of gas. So unless you plan on being by yourself after your egg protein powder shake there are better options.
Soy is another common option for those preferring a non-animal source of protein. Soy has a high digestibility score and is also considered a complete protein. Unfortunately, the phytoestrogens (estrogen like substances found in most plant foods, but particularly high in soy) in soy are generally believed to be beneficial in small to moderate amounts but seem to be counterproductive in large amounts. Also, unless soy is fermented, it contains enzyme inhibitors that block the action of trypsin and other enzymes needed for protein digestion.
Hemp is another newer protein powder on the market. Hemp is unique in that it is the only protein powder that is not processed and considered a raw food. Though it is not 100% protein it is a complete protein and contains valuable fiber and omega-3 fatty acids. It is also extremely high in magnesium and iron. Hemp is my top pick due to minimal processing and amazing nutritional profile. Unfortunately, hemp is not my favorite pick for taste (though none of them taste great on their own), but does taste good mixed with oatmeal or prepared as a smoothie.
The other two options I have found on the market are pea and brown rice protein. Both of which are sold separately or as supplements mixed together. I haven't personally tried these two but have read reviews that the taste is not completely appealing. Another disadvantage is that separately they do not form a complete protein. Rice protein tends to be low in lysine, an essential amino acid, while pea protein tends to be low in both cysteine and methionine. However when combined they do contain a complete protein.
There are obviously a lot of choices and considerations (taste, price, nutritional quality, and plant vs animal origin) when choosing a protein supplement. Many of these protein supplements also add vitamins and minerals as well as artificial sweeteners, sugars, or even trans fat. My personal suggestion is buy one that does not contain any added ingredients and develop your own personal recipes when using them, or just add them to some of your favorite recipes for extra protein; but remember that these all contain extra calories as well. Also, be careful not to overdo any one of them. Excessive protein can be harmful for your kidneys and your bones.
