Now that we have the basics of what protein is and about how
much your body needs, let’s address the sensationalism that goes along with it.
We’ve all seen whey protein powders plastered with pictures of ripped muscles.
Promising muscles just like that if you drink whey protein before, during, and
after your workout in the amounts recommended by the product label. Nutrition
research is still developing in the field of sports nutrition. Out of the countless
supplements and nutrition recommendations that are out there, there are
actually very few with strong, research-based studies supporting them. In nutrition
research, it is very difficult to say that if you do A and B, then you will get
C. There are too many variables (such as genetics, overall diet, lifestyle, and age) playing into
the results to be able to say that the results are due to one nutrition factor.
Below are answers to a couple of commonly asked questions backed by non-biased,
evidence-based research studies.
When should I eat
protein?
Supplements will tell you that you need to have protein
before, during, and after your workout to see the results that you want. There
seems to be little benefit consistently found from pre-exercise and during
exercise feeding of protein in muscle gains (1). The greatest gains and
improvements have been found with protein intake within 2 hours AFTER training
for muscle gains (2). This is because muscle protein synthesis is elevated to
the greatest extent within the initial hours after the exercise session. Eating
protein within that window provides building blocks that your muscles need.
The amount of protein recommended varies for each individual, but no further
benefit has been found eating over 20 g of high-quality protein during that 2
hour window (3). Another study from the Journal of Nutrition found that muscle
protein synthesis was 25% higher when protein was evenly distributed across
breakfast, lunch, and dinner compared with a more typical pattern when the most
protein was consumed at the evening meal (4).
Bottom line: Spread your protein evenly throughout your meals in
the day. Eating protein (no more than 20 g) within 2 hours of a workout
maximizes muscle synthesis.
What type of protein
is best?
Not all proteins are created equal. Proteins are digested
differently in the body and enter the bloodstream at different rates depending
on the amino acid profile of the protein. This is useful when determining what proteins
to eat after a workout. Milk is made up of two proteins, whey and casein. Whey is
a complete protein that is easily and rapidly digested. This makes it ideal as
a post-workout protein during the 2 hour post-workout window (1). Casein is
commonly recommended to be consumed later at night because it is digested more
slowly which makes amino acids available in the blood stream for a longer amount of time. Two studies conducted in both men and women show that consuming
500 mL of milk within 2 hours of full-body resistance training showed the
greatest gains in muscle mass and loss of fat mass (1). Various studies have
indicated that plant-based proteins (ie, soy) have relatively inferior results
in training as compared to animal proteins (5). Complete proteins (ie, chicken,
turkey, fish, dairy, eggs) consumed in the recommended amount and evenly
distributed throughout the day will help to achieve muscle protein synthesis.
Bottom line: Dairy products and their
protein components have been shown to produce the greatest gains of muscle mass
and greatest loss of fat mass when consumed within a post-workout 2 hour
window. Eating adequate proteins throughout the day helps the body have the
appropriate building blocks to build muscle.
Protein Supplements
or Food?
Protein supplements are advertised as an effective way to
increase muscle mass and strength. Whey protein supplements exist as
concentrates (~80% protein), isolates (usually >90% protein), and
hydrolysates (usually >90% protein) in powder form (1). Soy, casein, hemp,
and pea protein supplements are also available on the market. Supplements are
not regulated by the FDA, therefore you cannot always be sure that what the
label says is what you are getting. Protein supplements are considered a safe
and effective source of protein for increasing muscle size and strength, but it
must be part of proper caloric and protein intake in the presence of
resistance training (1). Protein supplements can be an easy, fast source of
protein, but may be unnecessary and expensive. Protein supplements are
concentrated forms of protein. Foods have been processed and the protein has
been extracted in order to create the product on the shelf. That processing
leaves out vital, important nutrients that are found in foods. Whole foods are
irreplaceable. There is a reason that studies consistently show that the
healthiest people are those that eat a balanced diet of whole grains, lean
proteins, low-fat dairy, vegetables, and fruits. Food has components and
nutrients that cannot be replicated in supplements. As an
occasional replacement for a meal or post-workout snack supplements have their
place, but real, whole foods should be the main component of every diet.
References:
1)
Rosenbloom, Christine A., Coleman Ellen J. Sports Nutrition: A Practice Manual
for Professionals; Protein and Exercise. 2012; 39-42,45-46.
2) Burd NA,
Tan JE, Moore DR, Phillips SM. Exercise training and protein metabolism:
influences of contraction, protein intake, and sec-based differences. J Appl Physiol. 2009;106:1692-1701.
3) Moore DR,
Robinson MJ, Fry JL, Tang JE, Glover EI, Wilkinson SB, Prior T, Tarnopolsky MA,
Phillips SM. Ingested protein dose response of muscle and albumin protein
synthesis after resistance exercise in young men. Am J Clin Nutr. 2009;89:161-168.
4) Mamerow
MM, Mettler JA, English KL, et al. Dietary protein distribution positively
influences 24-h muscle protein synthesis in healthy adults [published online
January 29, 2014]. J Nutr. doi: 10.3945/jn.113.185280.
5) HartmanJW,
Tang JE, Wilkinson SB< Tarnopolsky MA, Lawrence RL, Fullerton AV, Phillips
SM. Consumption of fat-free fluid milk after resistance exercise promote
greater lean mass accretion than does the consumption of soy or carbohydrate in
young, novice, male weightlifters. Am J Clin Nutr. 20078;86:373-381.
Janae Decker RD, CD
