While I’m working on a few other articles on other topics (including training to failure, the metabolite theory of growth and a detailed examination of what muscular tension is and isn’t), I want to do a quick update on the topic of protein requirements for athletes. This is a topic with literally decades of history behind it.
The Debate Over Protein Requirements
Early on, the debate was primarily between scientists, who often argue that activity did not increase protein requirements and athletes who did (the athletes, to a first approximation turned out to be correct, by the way).
There have also been long standing debates between scientists on different sides of the same debate (some of the big names that will come up in this piece are Stuart Phillips, Kevin Tipton and Robert Wolfe) with some giving relatively lower recommendations (but still higher than the RDA/DRI levels) and others relatively higher.… Keep Reading
Protein quality refers, in a general sense, to how well or poorly the body will use a given protein. More technically, protein quality refers to how well the essential amino acid (EAA) profile of a protein matches the requirements of the body; the digestibility of the protein and bioavailability of the amino acids (AAs) also play a role (1,2).
Essentially, protein quality simply refers to how well or how poorly a given protein is used by the body once it has been digested. Clearly, any protein that escapes digestion can’t do anything in the body but that doesn’t mean that all of the protein that is digested automatically works the same in the body.
Repeating myself slightly, protein quality has to do with how well a given dietary protein is used by the body for all of the different purposes that protein is used for. … Keep Reading
Continuing from the topic of protein digestibility, I want to next look at the issue of speed of digestion. This issue first came to light in the 1990’s as it was realized that dietary proteins digested at different speeds and this impacted on how they were utilized by the body.
It’s turning out that proteins can digest at fairly different rates and this turns out to affect various physiological processes; the main two are protein synthesis and protein breakdown. As with the last article, I’m going to talk about these terms in brief before moving onto the main thrust of today’s article.
Because I have a lot of information to cover, I’m going to break the topic down into two parts. In Part 1 today, I need to cover a bit more background physiology and talk about the original study that kicked off the entire interest in speed of digestion. … Keep Reading
Moving on from the topic of protein quality I want to wrap up this guide to dietary protein source by looking at a grab-bag of other factors. This includes the micronutrient content, dietary fat content, and other issues such as availability, the protein content and price.
Outside of a few select groups (that often get a majority of their protein from isolated sources such as protein powders or amino acids), most people get their daily protein from whole food sources and whole foods contain other nutrients. Some of those nutrients may be beneficial, some of them may be detrimental. But all are worth considering.
The major ‘extra’ nutrients I want to look at in this article are zinc, iron, B12, calcium. In the next part of this article series, I’ll take a look at the issue of dietary fat content, both in terms of good and bad fats. This is simply to keep the length a bit more manageable.… Keep Reading
The most recent piece I wrote on the topic addressed a current idea in field where maximal per meal protein intake is about 0.25 g/lb (about 0.55 g/kg). This is based on research showing that this amount of protein maximizes MUSCULAR PROTEIN SYNTHESIS. This is assumed to represent the optimal protein requirement for growth.
In the original piece, I gave a number of criticisms of that idea including the following:
Most studies concluding this use whey protein rather than whole food. This not only alters digestion and appearance kinetics but the food matrix is important as the presence of other nutrients and compounds impacts on how foods work in the body.
In the previous section of this guide, I examined the issue of amino acid profile, primarily as it relates to general health and wellness. My basic conclusion, based on the research is that basically any high quality protein source more than adequately meet the amino acid requirements of adult humans. In the modern Western world, obtaining sufficient protein is not an enormous issue and quality is unlikely to matter enormously.
Two specific amino acids that tend to get focused on by athletes are the branched chain amino acids (BCAAs) and glutamine, I’ll give a quick primer on those before discussing any of the other specific issues.… Keep Reading
A long standing debate in the field of nutrition is how much protein should be consumed after training to provide an optimal stimulus for protein synthesis. Let me note that only focusing on MPS is short-sighted at best and moronic at worst. Today I want to look at the following paper which addresses the issue.
This paper is quite timely given that I’m currently mired (yes, mired) in the around workout nutrition chapter of the woman’s book. Now, in recent years, the whole post-workout nutrition thing (or more generally around workout or peri-workout nutrition) has become a little bit more confusing than it was originally.
Back in the day everybody knew you had to consume carbs and fluids (endurance athlete) or carbs and protein (resistance training) for optimal results.… Keep Reading
Many websites offer simple answers to that question, generally revolving around whatever protein they happen to sell; the answer, as always, is far more complicated than that. A large number of variables go into the declaration of what a good source of protein is and, as always, what is good in one context may not be good in another. I’d note that this topic was of sufficient interest to me that I wrote an entire book about the topic.… Keep Reading
Before looking at whole proteins and protein powders, I’d like to address some of the most common protein controversies that tend to surround the high protein intakes typically seen in and recommended to athletes. The major ones are kidney function, bone health, and heart disease and colon cancer. Related to the issue of bone health, I’m also going to address the topic of metabolic acidosis and the impact that dietary protein intake has upon it.
A common criticism of high protein intakes/diets is the concern that they are damaging to the kidneys. This belief seems to stem from the fact that, in individuals with preexisting kidney damage, protein intake often has to be reduced to prevent further development of the disease. Incorrectly, this has been turned around to suggest that high-protein intakes are damaging to the kidneys.… Keep Reading
The topic of soy protein tends to bring up lots of argument and debate and certainly there is some good reason for this. Depending on a huge number of factors, soy protein can be good, bad or neutral. In general, the extreme stances are just that and the reality lies in the middle. But the topic of today is not soy protein in general (discussed in detail in The Women’s Book Vol 1). Rather, I want to examine if soy protein impacts thyroid function.
To examine the topic, I want to look at the following recent review:
To give readers a brief background on the topic, the thyroid gland releases two primary hormones T4 and T3 (thyroxine and trio-iodothyronine respectively) in a ratio of roughly 80:20 in response to the signal sent by TSH (thyroid stimulating hormone). … Keep Reading