Month: December 2008

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.

Micronutrient Content

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

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.

Amino Acid Requirements for Athletes

Today, I want to continue that by looking at some issues specific to athletes and those involved in heavy exercise training.  It’s fairly well established that athletes need more protein than sedentary individuals although there is still great argument over just how much is needed.

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

Having examined the impact of speed of dietary protein digestion, I want to talk about protein quality.

What is Protein Quality

Quoting directly from The Protein Book:

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

Although athletes have long known the benefits of a higher dietary protein intake, research is finally catching up.  The idea is also becoming more prevalent in the general public as people realize that higher protein intakes are better for dieting, fat loss and appetite control.  But this raises just as much confusion as people wonder about the different dietary protein sources in terms of which is better (or best) than another.

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