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Appetite For Construction
Mar 30 2001

By Dr. John M Berardi, Ph.D.
First published at www.t-mag.com.

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Protein Quality

Q: Bioavailability Ratings… Biological Value… Protein Efficiency Ratings… can you please explain, once and for all, what all these terms mean! Are some proteins really better than others? If so, why?

A: Sure, I'd love to explain it once and for all. But undoubtedly I will have to explain it 1000 more times in my life so do me a favor: print this out and hand it out on the street corners in your hometown. That will probably save me some work in the future. It's the least you can do since I'm answering your question. And if I do get asked this again, I'm gonna hold you personally responsible, ok?

In all seriousness, let me address the question of protein "quality." The first thing to consider when talking about protein quality is the fact that proteins are nothing more than long strings of individual amino acids strung together like Mardi Gras beads. And it's the type of amino acids (or beads) that determine protein quality.

The best dietary sources of protein have an amino acid composition that most closely approximates the make-up of human protein. But even more importantly, quality protein contains adequate levels of what are known as the indispensable amino acids. These are amino acids that must be obtained from the diet. The body can make some amino acids (the non-essential ones) but not others (the indispensable ones). If you don't eat enough of the indispensable ones, both growth and protein synthesis suffer.

Today, some pretty neat scientific methods are used to determine protein quality. The most discussed (and abused) measure is that of the protein's biological value (BV). The BV of a protein is calculated by measuring the percentage of protein eaten and absorbed into the blood, but not excreted.
To get this measure, you've gotta figure out how much protein was in a meal, how much got into the blood, and how much showed up in the urine/feces later on. And yes, you do actually have to collect each of your subjects' stool and urine samples each day in a huge bucket and finger through it to do your nitrogen analyses. Even though it's permissable to use gloves, you now know why I will never do a BV study. "Well, Mr. Luoma, your nitrogen balance sucks, but it sure looks like you had a big breakfast."

Anyway, these measures then give an indication of how much of the protein that was eaten actually remains within the body to be incorporated into protein stores.

The reason why I say this measure is abused is that there is no way that BV can be greater than 100%. That would mean that there was a negative amount of protein excreted. But since you see BV's reported of 120% or greater all the time, what gives? Well, what happens is that the BV for any given protein is compared with a "test protein" like egg protein. Then the value given is as a percentage BV relative to the egg protein. Since egg has a high BV, it's given a rating of 100%. And each protein measured is then given as a % of egg protein's value. So, since whey protein is better than egg in this respect, it has a score of greater than 100%. All in all, a BV of 70% or above is considered good quality.

The second measure of protein quality that you'll often see discussed is the protein-digestibility amino acid score (PCDAAS). This measure is different from BV as it determines the indispensable amino acid content of the protein measured. These values are then compared to the known amino acid requirements for growth in humans. Once this comparison is made, it becomes evident whether or not there are adequate amounts of each amino. The amino acid that is lowest in the protein being measured is then termed the "limiting amino acid" because a protein is only as good as its weakest link. This value is then given to the protein of interest.

I know this seems complex, but here's an example that might make it more, uh, digestible. If I'm looking at wheat protein, I know that the amino acid lysine is very low in this protein, relative to the known human need for lysine. So in wheat protein, lysine is the limiting amino acid. Since the adult requirement for lysine is 19 mg for every gram of protein consumed, and wheat may only contain 8 mg of lysine for every gram of protein consumed, the PCDAA of wheat protein is 8 divided by 19. This gives a value of 0.42 or 42%. A PCDAAS of 1.00 or 100% is good quality. So wheat is not a good quality protein. Any lower than 1.00 or 100% and the protein must be combined with another source that may contain sufficient quantity of the low amino acid. A score of 1.00 or 100% is the highest a protein can score.
The following is a chart showing the different scores of common protein sources:

BV and PCDAAS of Selected Proteins

Adapted from:
a) Colgan, Michael PhD, The Right Protein for Muscle and Strength (1998) Progressive Health Series Colgan Institute, pg. 20 BIOLOGICAL VALUE OF PROTEINS;
b) FAO/WHO (1990) Report of a Joint FAO/WHO Expert Consultation on Protein Quality Evaluation, Food and Agruculture Organization of the United Nations, Rome;
c) Schaafsma, G. The Protein Digestibility-Corrected Amino Acid Score. J Nutr, 130: 1865S-1867S, 2000.

What you should notice from this chart is that the animal products seem to score better on both the BV and PCDAAS scales. This is why animal derived proteins like egg, milk, casein and whey are typically the proteins that bodybuilders will choose. Low quality proteins like beans, grains and peanuts can be eaten, but combining a few different low quality proteins like grains and milk proteins or rice and legumes (beans) would be necessary to get the required amino acids for growth. Just don't let anyone stand down wind of ya'.

Here's a chart showing what the limiting amino acids are in "low quality" protein sources. By combining some of these, you can make up for the limiting amino acids in each of the combined foods.

At this point, you may be asking yourself, "So what does all this mean?" Well, the bottom line is that there shouldn't be a big difference in "protein quality" with sources containing a BV of 70 or greater and a PCDAAS of close to 1.00. Now go tell your friends!

Whey vs. Casein

Q: Your site keeps talking about the differences between whey protein and casein protein. I know that whey is quickly absorbed and casein is more slowly absorbed. Some also say that whey is anabolic and casein is catabolic. Is all this true? And if so, how do I use this information to make me bigger?

A: It's true! I swear that when I'm on whey protein, it feels like I'm on 200 milligrams of Testosterone each day. In fact, I usually gain about 30 lbs on a good cycle of whey protein and the pumps I get in the gym are incredible! Be careful, though. If you're on whey for too long, you might get some nasty side effects.

Okay, I'm just being an asshole. But in all seriousness, people need to drop this silly idea that different protein sources have magical anabolic and anti-catabolic properties. Sure, whey and casein have different absorption rates and this means that they could have slightly different physiological effects, but just try not to make things too complicated.

For a more intensive discussion about the different properties of whey and casein, read Cy Willson's "The Protein Wars" and my article, "The Protein Roundtable". These articles go in depth about the differences between the two.

However, I want to use this column to address some specifics as to how to apply this information; in particular, what I think the best times to take in each type of protein or a protein blend:

Pre-bed meals and nighttime meals: Bedtime meals or meals in the middle of the night should be high in casein. The percentages don't really matter. Sure, you could include some whey, but since casein is more slowly digested and absorbed into the blood, it should make up the bulk of the protein in these meals. This will help to ensure a better blood amino acid profile throughout the night. Some suggestions for these meals are non-fat cottage cheese with some casein, Grow!, or Advanced Protein mixed in; casein powder, Grow!, or Advanced Protein mixed in skim milk; oatmeal with casein, Grow!, or Advanced Protein mixed in.

Post-workout meals: Post-workout meals should contain whey protein hydrolysate as the only protein source. Since this is the most rapidly and efficiently absorbed protein source, it will quickly supply muscles the much needed amino acids for recovery. If you are not going to use hydrolysates however, at least choose a whey-only source because of it's relatively rapid absorption and delivery when compared with other drinks. Most of you already know my suggestions for post workout nutrition, but if you don't, check out my articles, "Solving the Post Workout Puzzle," Part 1 and Part 2.

"Normal" meals: These meals, while they should be high in protein, can consist of any darn source you want. If you're on a regular eating schedule (every 2-3 hours) as you very well should be, then it really doesn't matter where the protein comes from. However, if you still insist that you're too busy to eat regularly and only get 3 meals per day, be sure that you add some casein from powder, milk, or cottage cheese to your "normal" meals. This will serve to ensure that you aren't going catabolic in that long marathon between meals that you've chosen for yourself.

n the end, the protein source matters only when you consider the timing of the protein intake relative to what you've done before the meal and what you'll be doing after the meal. In the long run, smart protein decisions will probably make a good contribution to your physique progress. And if you're lucky like me, choosing the right protein might just make you feel like you're on Deca (just kidding again).

Coming off of a ketogenic diet

Q: I've been following a ketogenic diet for nearly a year now. I would love to come off the diet because it has killed my sex drive and my progress in the gym has all but halted. I lost a good amount of fat on it for the first couple of months, but then my progress stopped. The problem is that when I try to go off the diet and eat normally again, I blow up. Help!

A: Buddy, you're not alone. Although the ketogenic diet works very well for some individuals, the majority of weight trainers have the same problems that you mentioned. But they're too afraid to go off the diet because it appears that they'll rapidly gain back a lot of fat and end up where they started. And they're too afraid to get help. Remember the old saying… the first step toward getting help is admitting you have a problem.

There are several reasons why people blow up and gain a lot of weight when trying to come off ketogenic diets. They include:

Carbohydrate intolerance: While on a ketogenic diet, the body becomes more efficient at using fat for energy and therefore "forgets" how to process carbohydrates. So for a few weeks after you start eating normally again, you'll be storing those carbs and getting fatter. Sure, a lot of it will go to muscle glycogen, but a much larger amount than expected will go to fat stores. It takes a few weeks for the body to "remember" how to process carbohydrates.

Insulin Resistance: Ketogenic diets decrease insulin sensitivity. In fact, in people coming off ketogenic diets, the symptoms are similar to those seen in type-2 diabetics! The likelihood of gaining fat due to this insulin resistance is high.

Stimulants: Most dieters abuse caffeine and ephedrine. Both of these substances decrease insulin sensitivity as well and can induce diabetic like symptoms when reintroducing carbohydrates into the body.

Water Gain: Ketogenic diets, because of their effects on fluid balance, can induce mild dehydration. Although this makes you look lean and "dry", it negatively impacts performance. Once you start eating normally again, the body hyperhydrates, causing massive water retention. Although sometimes uncomfortable, this typically leads to big gains in strength in the gym. However, all this water retention does make the physique "blurry." So most people mistake this water gain for fat gain. Unless you have body fat measures done regularly, it'll be hard to know whether it's fat or water.

So now that you know why you blow up, let me tell you how to avoid it:

• The first step is to plan a flexible 6-week transition period in which you'll taper off the ketogenic diet. The most effective way to transition here is to use the insulin and carbohydrate sensitivity measures discussed in part 2 of my Massive Eating Article. Now listen up… this is important. During this time you'll be supplementing with insulin sensitizing supplements. I recommend 600 mg of alpha-lipoic acid per day, lots of fish oils (at least 6g of DHA and EPA), glucosol (colosolic acid) at about 50 mg per day, and inzitol (d-pintol) at about 50 mg per day. Remember to take the ALA, glucosol, and inzitol during separate carbohydrate meals. Don't take them with a carbohydrate free meal or together. In addition, do your cardio. About 30 min 4x per week, separate from weight training, does wonders for increasing insulin sensitivity and carbohydrate tolerance.
• Have an OGTT and a fasted blood insulin and glucose sample taken at the beginning of the transition week (again, see part 2 of the Massive Eating Article).
• During weeks 1 and 2, gradually reintroduce carbohydrates into the diet. Try replacing 10% of your fat with high fiber, low glycemic and insulin index carbohydrates (if your diet is 60% fat, 40% protein change it to 50% fat, 40% protein, 10% carbohydrate). Some good carbohydrate sources are oatmeal, vegetables, nuts, beans, and fruits. This is easier said than done, though, because most often, when reintroducing carbohydrates into the diet, carbohydrate cravings go through the roof! So be prepared and be strong.
• At the start of week 2, have another OGTT and a fasted blood insulin and glucose sample taken. Your insulin sensitivity should be improved due to the supplementation. If not, stay on 10% carbohydrate 'till it is.
• For weeks 3 and 4, decrease your fat intake and increase your carbohydrate intake to about 20% of the diet, again using high fiber, low GI and II carbohydrates (now you will be at 40%fat, 40% protein, 20% carbohydrate). Follow this for 2 weeks while remaining on the recommended supplements.
• Again, at the start of week 4, have another OGTT and a fasted blood insulin and glucose sample taken. Your insulin sensitivity should be improved due to the supplementation. If not, stay on 20% carbohydrate 'till it is.
• For weeks 5 and 6, decrease your fat intake and increase your carbohydrate intake to about 30% of the diet, again using high fiber, low GI and II carbohydrates (now you will be at 30% fat, 40% protein, 30% carbohydrate). Once you get to this point, you should be home free.

So will this approach prevent all fat gain? No, but it will definitely minimize it. Just keep in mind that you'll probably gain some water and that this is a good thing. But this water does scare most people as they mistake it for fat gain. Just hang in there and the body will normalize over the 6-week period and you'll end up just fine.

Remember, this program requires a lot of effort and discipline, but it's very effective. Don't waste a year of dieting by indiscriminately changing your eating plan. You'll only get fat and/or frustrated. Or you'll never go off the diet that's making you unhappy.

Vitamins

Q: I try to take vitamins, but when you look at the label of any common brand, you want to go nuts. How do they figure out what vitamins to put in, and in what amounts? Wouldn't you think that a lot of these things would interact with each other? Got any advice as far as what vitamins to take?

A: If there's one area I'm not all that strong in, this would certainly be it. You see, I had this really hot teacher for nutrition class. And instead of concentrating on vitamins E and A, I was concentrating on her T and A. Oh, give me a break. I was 20 years old at the time! Anyway, although I "missed" an entire semester of nutrition, I did learn a thing or two about "office hours." Since then, I've had to pick up the slack on my own and I'm grateful for it because if I would have followed her advice, I would be recommending 80 g of protein per day for you bulky muscle headz.

But getting back to your question, it's a good one. Now, I usually say this either when it's particularly insightful or when I don't really have a good answer. In this case, it's probably the latter. When asking, "How do they figure out which vitamins to put in?" there's probably no good answer for most manufacturers.

While most simple and inexpensive, multiple vitamin formulas are simply designed to contain 100% of the recommended dietary allowance figures (these values are basically the minimum requirements necessary to prevent deficiency), I have no darn idea what the others are thinking. In some cases it seems like they arbitrarily jack up the doses of some nutrients that athletes may need more of. It's important to note that I say, "may." If the diet is adequate (and to be honest, most diets are woefully inadequate), extra vitamins may be unnecessary. Sure, athletes may need more in some cases. This is dependent on many factors, though, including: frequency, duration, and intensity of exercise as well as training environment, gender, total calorie intake, and food choices. You see, its pretty complex.

Anyone who knows my writing will be familiar with my recurring theme of individual differences. So if you really want to know what vitamins you need, you can have a medical lab evaluate your vitamin and mineral status. Then you can determine what vitamins and minerals you need to supplement. I say this because if you just randomly supplement, you may build up toxic levels of certain micronutrients. And rather than help you out, it will certainly ruin your training and potentially your health.

In addition to the problems of toxicity, high amounts of some vitamins and minerals can inhibit the absorption of others. So as a result of random vitamin supplementation you may have toxic concentration of one nutrient and a deficient concentration in another. An example of this is the interaction between high vitamin C intake and vitamin B12. High doses of Vitamin C (1000mg) may inhibit the absorption of B12 and may cause deficiency. There are many other examples of these types of interactions (folate inhibits zinc absorption, vitamin D improves calcium absorption, calcium decreases magnesium absorption).

So, understand that the optimal vitamin supplementation program would be based on lab results and a targeted regimen designed to improve any deficiencies. But since not every one can get these tests, my recommendations (for now) are to go out and buy a cheap multi-vitamin and mineral that contains about 100% of the RDA. Then take one per day as recommended. This way, you're pretty safe to assume that with the vitamin and your diet, you'll be avoiding deficiencies. If you'd rather concentrate on taking only those vitamins and minerals that athletes may be deficient in, the following table lists those that have been shown to be depleted or deficient in a good percentage of athletes:

Thiamin
Vitamin C
Choline
Vitamin D
Vitamin E
Calcium
Magnesium
Potassium
Iron
Selenium

If you want to make it more difficult than this by trying to figure out which vitamins interact and take them at different times during the day, go right ahead.

If you want to research this further, several new nutritional guidelines have been set for several vitamins and minerals. Some of these guidelines can be found on the internet at NutritionHealthreports.com/RDA.html. This guide has been compiled by the National Academy of Sciences and is an attempt to update the needs of different individuals. These reports also discuss interactions so go knock yourselves out.

But short of going through all these mental gymnastics, this simplest and most sensible thing (in my opinion) is to try your best to follow a varied and complete diet while supplementing with a multi-vitamin and multi-mineral formula that provides about 100% of the RDA values.