Protein has never been as popular as it is now. As a nutritionist, I find it interesting that so many myths about protein have come and gone, including the one that held that all any adult needed was the Recommended Daily Allowance (RDA), regardless of how much he or she trained, and that if you ate more protein than that, your kidneys and bones could be in danger. Obviously, a lot has changed, and in recent years, it has become clear that athletes and people who exercise regularly need more protein daily and that higher intakes are indeed safe.

In addition to high-protein foods, many athletes rely on protein supplements to strategically supply their muscles post-workout as well as to support greater daily needs. However, with so many protein supplements on the market, one of the most common questions I am asked is which one to buy. Below are some guidelines to assist you in picking the right protein type and product.

PROTEIN is the King of Performance Nutrients

Protein makes up roughly 80% of muscle mass (once the water is removed) and is responsible for muscles’ structure and action. That’s why protein intake is viewed by all athletes as absolutely critical to optimizing muscle size, strength and performance. And when it comes to protein supplements, the bottom line is that people who train seriously use protein supplements specifically to support muscle building (size) and the development of strength and power in response to training.

There are several protein types to choose from, each with its own unique aspects and potential benefits. And, when it comes to protein powders, milk proteins and egg are among the most desirable and are reviewed below. The concentration and processing of protein in powder form  yields different ingredients in that concentrates tend to be less than 85% protein (dry weight) and isolate are greater than 85%. Meanwhile, hydrolysates refers to the presence of partially digested proteins including polypeptides and peptides. In addition to providing amino acid building blocks, peptides might have additional actions in the body.

Whey Protein

Whey is the most popular protein mainly because it is the quickest to digest and absorb. That makes it more popular when consumed either immediately before or after a workout. Whey is approximately 20% of the protein in cow’s milk and there are four main protein types in whey: β-lactoglobulin, α-lactalbumin, serum albumin, and immunoglobulins. Whey protein has the highest branched chain amino acid (BCAA) content, including roughly 11% leucine and 9% of combined isoleucine and valine, yielding a 2:1:1 relationship. This is the ratio that is found within muscle fibers. Leucine is very desirable as it plays a direct role in optimizing muscle protein manufacturing after strenuous training and in response to a protein-endowed meal by increasing the activation of mTOR. Moreover, whey is probably the most thermogenic protein, meaning that the increase in calories burned per calorie consumed is greater than other proteins. This is likely tied to a more acutely potent effect on muscle protein synthesis.

Casein Protein

Casein is a slow-digesting protein especially when compared to its milk counterpart, whey.  Depending on how much you consume, casein can take more than six hours to be fully digested and absorbed by the body. Casein is a good source of BCAAs as well as glutamine. There are four principal casein protein families found in milk (αS1, αS2, β, κ) and together they are about 80% of the protein in cow’s milk and the protein component of cheese. In its natural state, casein exists mostly as protein spheres (or micelles) and contain minerals like casein and phosphates. Casein as a protein powder ingredient is typically 85-90% protein and ingredient panels typically call out “micellar casein” or more processed “caseinates”. Because of its slow digesting and absorbing properties it is often recommended before bed or in between meals either by itself or in blends with other proteins.

Milk Protein

Milk protein contains both whey and casein proteins in a natural 80/20 ratio of casein to whey. Milk protein is typically supplied as an isolate (>85% protein (dry weight) and concentrates (>85% protein, (dry weight)). Milk protein isolates and concentrates are commons in proteins powder blends as well as is creamy protein RTDs (ready-to-drink) and protein bars.

Egg Protein

Eggs are making a serious comeback as some of the long held beliefs that eggs contributed to the development of heart disease. There are eight main proteins in egg whites, including ovalbumin, conalbumin, ovomucoid, avidin, flavoprotein-apoprotein, “proteinase inhibitor,” ovomucin, and globulins. Egg proteins come from the white, which is about 11-12% of liquid egg white, and the yolk.  The egg protein found in protein powders is mostly egg white protein isolate and is a good alternative for people with milk allergies.

Protein Targeting and Timing

Most sport nutritionists agree that people who train hard and athletes need to make protein a major consideration and target it throughout the day. A good rule of thumb is to set a target at or around 20-30% of calories or 1 gram per pound of lean body weight target with personalization based on calorie level and meal frequency. So, for a lean 190-pound athlete eating 3,000 calories, this would be about 190 grams. Furthermore, each meal should be based on protein, whereby protein is at least 20-30 grams depending on body size and protein. This will help optimize muscle protein synthesis (MPS) throughout the day. Further, still there are three key meal targets during the day in which protein is critical:


During the night, muscle protein breakdown (MPB) is increased and losses can be 5-15 grams depending on body size and diet during that day and leading up to bed time. Protein and some carbohydrates first thing in the morning help reverse this negative impact on muscle protein and increase MPS. Breakfast should be a target for at least 20-35 grams of protein, again depending on body size, protein type and total protein (g) targets for the day.

Pre/Post Workout

A strenuous training session can elevate both MPS and MPB and the goal is to maximize the former and minimize the latter with either protein and some carbohydrates immediately before or after training. Like breakfast, at least 20-35 grams of protein again depending on body size, protein type and total protein targets for the day.

Before Bed

During the night, in an unfed statem muscle protein balance slides towards more MPB to generate free amino acids to help fuel the body. Consuming at least 20 grams of protein, or a lesser amount but with supplemental leucine to achieve 2+ grams will help keep MPS higher during sleep.

Protein Powder Facts and Fallacies

Most athletes and people training hard who are getting more protein throughout the day are deriving some of it from protein powders. Among the most important decision-making factors are protein types (e.g. whey, casein, egg), flavor, brand, and cost. What’s more, savvy protein shoppers are getting really good at looking at the ingredients to determine if all of the protein claimed in a serving is actually coming from real protein and not other nutrients that can count as protein, but don’t necessarily help muscle building. Some brands might have added amino acids like taurine, alanine, and glycine or amino-acid-derived ingredients like creatine and count them as protein. They’re able to get away with this because all those additional nutrients contain nitrogen, which is the element used by laboratories to estimate how much protein there is in a product. It’s then up to the brand to honestly label how much “real protein” is in each serving by subtracting out “nonprotein nitrogen” (e.g., added amino acids, creatine, etc.).

The further problem is that while those bonus ingredients have their own benefits, they don’t have a lot to do with muscle growth or performance. Taurine is an amino acid, but it doesn’t get used as a building block for protein. Glycine and alanine can indeed be used to make protein, but they are nonessential amino acids, and any extra amount your body gets is probably going to be used for energy purposes instead. And although creatine is derived from amino acids, it cannot be converted back to amino acids to make muscle protein. Taken together, this means that these extra sources of nitrogen, which might be labeled as protein, will not contribute to muscle-protein manufacturing. Said differently, even though there might be more protein per serving in certain protein powders, that might not result in more muscle-protein manufacturing.

Leucine: The Mark of Real Protein

So how can you know that the protein you’re taking is high quality and delivered in an efficacious level per serving? One standout marker is leucine, an essential branched-chain amino acid. Leucine is critical for muscle-protein production in response to training, and it seems to help maximize the mechanisms that “trigger” or stoke muscle-protein manufacturing and that result in strength, power, endurance and size development. In fact, some researchers have suggested that it takes at least 2.5 grams of leucine (or 5 grams of BCAAs) to maximally stimulate muscle-protein-manufacturing systems. So to make sure you’re getting maximal muscle- and performance-boosting impact from your supplement, look for call-outs for leucine content, as well as total BCAAs, on the protein powder’s label.

Helping people for more than two decades, Dr. Robert Wildman is known throughout the world as being an expert in nutrition. His professional activities have included teaching at universities and publishing research, providing seminars to health professionals, authoring books and serving as spokesperson for nutrition brands. Robert has dedicated his life to helping people learn how to eat and to live their lives longer and healthier. Dr Wildman is the Principal at Demeter Consultants LLC (, a private nutrition industry consulting firm.

Educated in some of the nation’s leading nutrition programs, Dr. Wildman has authored several nutrition books including The Nutritionist: Food, Nutrition and Optimal Health, Sport & Fitness Nutrition and The Handbook of Nutraceuticals and Functional Foods which are used by health professionals and students around the world.

Being a foremost authority on nutrition, Dr. Wildman has been interviewed on TV newscasts (photo from UPN Atlanta above) and for newspapers such as NY Daily News and LA Times. He is a authored articles and been quoted in numerous magazines including Status Fitness, Men’s Health, Woman’s Day, Honey and FIT.Style and numerous Men’s Health books published by Rodale Press. Dr. Wildman has presented national Sport Nutrition seminars to personal trainers and nutritionists and has been a panel member for the Columbus Marathon.

Dr. Wildman is a registered and licensed dietitian with the American Dietetics Association and has a PhD from The Ohio State University in Human Nutrition. He received his MS from The Florida State University in Foods and Nutrition and a BS from the University of Pittsburgh in Dietetics and Nutrition.

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