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Dietary Protein Sources – Protein Quality Part 1

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

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Dietary Protein Sources – Speed of Digestion

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

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A Complete Guide to Dietary Protein

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

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How Many Carbohydrates Do You Need?

How many carbohydrates do you need to eat?  This is one of those perennial questions around which there is endless debate.  One the one hand, mainstream nutritionists continue to recommend very high carbohydrate intakes.  On the other are “fringe” groups who are convinced that carbohydrates are the cause of all ills in the world.

And while I have discussed these controversies previously, primarily focusing on health issues, I want to look at the topic again in a more athletic context.

Carbohydrate Intake Recommendations

It’s safe to say that most carbohydrate recommendations that you will see are put in terms of percentages, you should be eating 45% of your calories as carbs, or 65% or whatever number is being used.

Now, I don’t like to use percentages to set up a diet as they can be terribly misleading. A low percentage of a very high calorie intake may have more total carbs than a high percentage of a lower calorie intake.… Keep Reading

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Controversies Over Carbohydrate and Fats

In nutrition, it’s rare to find a complete consensus on anything.   Even with decades of data there continue to be controversies surrounding dietary protein intakes, generally revolving around kidney or bone health, among others.  But even those pale in comparison to some of the current arguments or controversies over carbohydrates and fat.   While there are many, the main ones I will examine here will have to do with the health related controversies.  Body composition issues will have to wait for a separate article.

Two (or Three) Dietary Camps

Generally, folks fall into one of two camps regarding whether they think carbohydrates or fats are good or bad. For a couple of decades now, the mainstream of dietary advice has been more or less stuck in the mindset of “fat is evil” and “carbohydrate is good”  This trend started with the early work of Ancel Keys on dietary fat and heart disease .Keep Reading