Shoppers may feel one protein is as good as another. But, according to Tim Marr, sales director at Nutrex Hawaii, Kailua-Kona, HI, “Studies have shown that not all proteins are equal.” 

Urban breaks it down: “Some offer more complete amino acid ratios than others with higher amino acid content, but ultimately, it is the choice of the athlete.”

Clouatre, among others, believes that whey protein is the “king of the muscle building proteins” because of its high content of l-leucine, a BCAA that can induce muscle synthesis.

Whey protein is the mixture of nine essential amino acids and studies have shown possible health benefits such as supporting healthy weight management as well as maintaining cholesterol and blood pressure in a normal range (4). In athletes, taking whey protein during resistance training helps promote the growth of lean tissue mass (4).

Whey protein is said to be the protein of choice for those looking to build muscle mass with a more toned look, according to Sugarek MacDonald. “The amino acids derived from whey are typically associated with protein synthesis and oxidation…so it is great for muscle building, but not repair.”

Derek Dearwater, president of Naturade, Irvine, CA, agrees that whey protein’s advantages over different types of proteins are its fast digestion and absorption. He states that, after a single serving of whey protein, it only takes 40 minutes for the blood level of amino acids to reach its peak and about an hour for the level to return back to normal in most people.

“This is amazingly fast in comparison to its counterparts casein, plant-based proteins or even whole foods,” says Dearwater.

In addition to muscle synthesis, digestion plays a big part for shoppers when deciding which protein to purchase. According to Elizabeth Poon, director of marketing, nutritional brands, at Country Life Vitamins, Hauppauge, NY, whey protein is also “one of the easiest forms of protein to digest.” While it is arguably the most popular type of protein, she suggests that anyone trying to avoid lactose should consider an ultra-filtered or micro-filtered whey isolate protein because it is 99% lactose free.

Marr argues that plant-based proteins should be an option because the “body absorbs it the best, much better than whey, because it recognizes it as food.”

Emma Andrews, RHN, NPDP, national educator for Vega Nutrition, Burnaby, BC, Canada, states, “If an athlete is at all sensitive to whey or casein proteins or their digestive tract is compromised, the absorption and utilization of amino acids will be impaired.”

When it comes to other proteins, including plant-based proteins such as pea, hemp, chia, rice, soy and others, Dearwater says they “have the advantage of being easier to digest for those people that may have a dairy allergy such as lactose intolerance, which affects over 50 million Americans.”

But, plant-based proteins provide more benefits than just being easier to digest. Says Sugarek MacDonald, “According to research, when supplemented, vegetable protein was found to help improve immune function, support a healthy weight and lean body mass, and aid in maintaining healthy blood pressure, cholesterol and glucose levels that are already within the normal range.”

Shoppers must also consider the amount of amino acids the protein they select contains. According to Poon, even though they provide fiber and essential fatty acids that are not found in whey protein, “plant-based proteins don’t provide complete amino acids on their own.”

But, there are some exceptions. Marc Stover, vice president of sports nutrition for Twinlab Corporation, New York, NY, feels that “vegan customers need to be aware that single vegan sources of protein may not be complete, however, and so should choose blends that take the care to provide a full spectrum of amino acids.” 

In addition to whey and plant-based proteins, many companies use new sources of protein in products. For example, Scarlett Blandon, MS, RDN, head of research and nutrition scientist for Axiom Foods Inc., Los Angeles, CA, refers to the impact of rice protein.

She says that “leucine, the key amino acid that triggers muscle development, absorbs faster in rice protein than whey,” and rice protein provides athletes “the only 90% isolate with the highest amount of protein available.” Some brands are also very low carb.

One study has shown that rice protein and whey protein aid in exercise performance equally (5).

Mixing proteins is an option, too. Clouatre believes “a mixture of proteins with different rates of digestion and assimilation is superior to single protein sources.”