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RX Files Pt. 2

The Truth About Protein Is Out There?and French Researcher Yves Boirie Is Uncovering a Lot of It

While I would never be so negative as to claim that bodybuilding has had its day, no one can deny that the sport has peaked. Somewhere back in the ’80s, when Platinum Everywear was everywhere and knockoff Met-Rx was a currency, the luster started to fade. As the owner of a hardcore spit-and-sawdust gym for many years, I can vividly remember when every new Arnold flick brought a horde of young new recruits through my door, each with seemingly limitless enthusiasm. Most had the genetic potential of Mr. Bean, yet they happily loaded the bars for the big boys’in hopes that they would garner vital trade secrets from one of the behemoths.

That was then. Today, I get guys calling to see if I have a juice bar or Pilates classes. What the hell happened? Was it something they put in the water?

The truth is that bodybuilding hasn’t really needed any help in destroying itself. Some feel that the exposure of the drug scene has played a part, saying that it has promoted skepticism about the importance of nutrition and the value of anything nonpharmaceutical. That’s a fair argument, but take a look at the direction in which bodybuilders themselves have moved. Today’s Olympia contenders look like caricatures. Physiques that few can relate to now relegate anything less than freaky to the also-ran section. Then there are those training routines’the labors of Hercules, with inconceivable volumes and tonnages that would fray your tendons and leave you with adrenal glands the size of cantaloupes. What about nutrition? How about a diet based on the daily food intake of a Third World country. In short, the unattainable achieved by doing the impossible and consuming the indigestible.

What relevance do the highly exaggerated practices of the chemically assisted and genetically gifted have to the goals of the average rookie? Contending with such a spartan lifestyle and finding error at the end of each trial would drain the enthusiasm of even the most die-hard obsessive. Many of the breakthroughs in sports science have more relevance to bodybuilding than perhaps any other sport, yet little of that technology has so far been applied. Several years ago IRONMAN took the initiative by adapting such principles as periodization to bodybuilding. Through the use of charts, percentages and the micro-, meso- and macrocycles, a new scientific approach offered you muscle by the numbers. The use of magnetic resonance imaging (MRI) studies further eliminated guesswork by showing us which exercises are the most efficient at getting the job done. Unfortunately, few have continued down that avenue, but at least the information is out there if you look hard enough.

With ‘Rx Files’ it was my intention to review the application of science to sports nutrition’in particular, the area of protein metabolism. Although some constants have been established, for the most part we’re still pretty much in the realm of guesswork and theory, relying heavily on the qualifications of those doing the guessing. For example, we still can’t put a figure on the ideal daily protein intake for an athlete. As it happens, how much protein may not be the single most important issue. The timing of that intake may be more significant. In Part 1 of my interview with Yves Boirie we discussed the two studies conducted by his team examining the principle of dietary ‘fast’ and ‘slow’ proteins. From those studies and that interview we can establish that the following facts need to be taken into account when planning your nutritional strategy:

‘The digestion rate of the protein from a particular source’e.g., whey, casein, chicken’is an independent factor that influences the amount of protein the body actually retains.

‘While ‘fast’ proteins can dramatically stimulate protein synthesis, if you don’t change protein breakdown, you may still end up with a negative balance. Therefore, the most important factor for improving protein balance is a prolonged amino acid elevation, as that is the way to inhibit protein breakdown.

‘Thus, in young adults ‘slow’ protein is far better with respect to net gain.

Yves Boirie has been involved in three studies in the area of protein synthesis. It all kicked off with a study looking at how to improve protein utilization in the elderly.1 In elderly people protein loss can have serious implications, particularly in relation to trauma and immune function. Improving protein retention would limit muscle loss and improve anabolism. Merely increasing protein intake had previously proven ineffective at improving retention. In that first study 15 healthy elderly women were divided into two groups, each following a different feeding protocol. The subjects in the first group were given a diet in which the daily protein intake was spread fairly evenly over four meals in a 12-hour period. The second group followed what was termed a ‘pulse’ feeding pattern, where around 80 percent of their daily protein intake was consumed at noon, the remaining protein being divided between the morning (7 percent) and evening (14 percent) meals.

The study found that the nitrogen balance was much more positive with the pulse-feeding pattern than the spread pattern. That result came about via a greater increase in protein synthesis and decrease in protein degradation. Interestingly, even though both groups had identical daily protein intakes, the spread-pattern group suffered a decrease in fat-free mass. The conclusion was that the protein-pulse-feeding pattern was more efficient at improving protein retention in elderly people.

The team next decided to see if the pulse-feeding pattern was more efficient at improving anabolism in young women. In a second study they determined that the two feeding patterns did not have significantly different effects on protein retention in young women.2 However, the third study found discrepancy with the previous conclusion and revealed a little more.3 It established not only that the pulse pattern was able to induce chronic regulation of protein metabolism in both young and elderly women but also that the modification persisted for at least one day after the subjects returned to their normal diet. In other words, the pulse-feeding protocol led to an improved protein synthesis response to a meal and a better protein-sparing effect in the postabsorptive period. When meals that are both high and low in protein are combined during the day, the pulse-feeding pattern improves anabolism by allowing for the advantages of both diets; i.e., high and low protein.

Since that information has to have some application to bodybuilding, I put several questions about the protein-pulse-feeding protocol to Boirie. Brian Batcheldor: In the May 2000 paper you indicate that in both young and elderly women a pulse-feeding pattern may be superior in terms of leucine kinetics to a spread pattern.3

The differences in protein retention were quite significant in the young women in the study. That’s very interesting because in sports nutrition we’ve been told for many years that it’s better to consume around six to eight protein meals a day to improve protein retention. Yet that advice seems to be based on no scientific data at all. In fact, your research indicates that the pulse pattern may be far superior at improving anabolism. Would you agree?

Yves Boirie: I think that one big point of this study is the fact that the subjects were prepared before the real study. For two weeks they received a lower amount of protein, around 1.2 grams per kilogram of fat-free mass. That was to adjust everyone to a similar protein intake. That’s a key point: this preparation, especially in elderly people. A second point is that we could see a greater difference in the elderly people than in the young people. That could be interpreted as young people can adapt to different protein feeding patterns better than older people.

BB: What was the amount of protein increased to for the actual study?

YB: It was 1.7 grams of protein per kilo of fat-free mass, so that’s close to around 1.4 grams per kilo of bodyweight.

BB: So it was quite a moderate protein intake; it wasn’t low?

YB: Yes, it was quite moderate. But by just playing with the repartition in the day, we have a huge difference in the elderly, not in the younger subjects. Those studies weren’t done with physical exercise, however, so we don’t know at all the impact of physical exercise with that kind of protein feeding pattern. But that could be a big issue, I think.

BB: Yes, it seems very significant in that it’s contrary to everything we are told in traditional sports nutrition.

YB: I’m not aware of any scientific data on those feeding patterns in relation to exercise.

BB: Yes, that’s right, and that’s what makes this so fascinating.

YB: Another important consideration is the impact of the nonprotein meals on the success of the pulse-feeding pattern. There is a huge protein meal, and then there is a nonprotein meal. There is some reason to think that the effect of the pulse-feeding pattern is maybe also due to the nonprotein meals.

BB: So what you’re saying is that maybe the carbohydrate and fraction of the meals may have contributed more significantly to those results?

YB: Yes, especially after a big protein meal. It could mean that the combination of either carbohydrate or lipids with protein may be very important’not in the same meal, but in different meals. They may behave differently when taken apart.

We were very surprised to see that after 14 days of that regimen we still had the changes one day after the protein feeding pattern was reduced, but we don’t know how long it lasts. There’s some evidence that the difference in elderly people disappears after 30 days, but at the moment we don’t know for sure.

BB: We briefly discussed earlier the excessive protein intakes of some athletes, around 400 to 500 grams a day. If any athlete was consuming a large daily protein intake without the help of any external influence, such as anabolic steroids and growth hormone, then anything that induced a chronic regulation of protein metabolism would surely be beneficial, wouldn’t it?

YB: That’s what we are trying to determine. Maybe we’ve succeeded in showing that there are other ways to improve protein balance.

BB: What impact do you feel the types of protein consumed had on the results?

YB: In the studies we used foods from a normal French diet’meats, cheeses and so on. We don’t know at the moment what the behavior is of all those different proteins. That’s a huge area for more studies. What I can tell you, for example, is that peptides are absorbed differently, as are free-form amino acids, so we’re talking about not only the foods but the molecular form of the protein given.

BB: Is it possible that if the focus of your earlier studies had been on using slow proteins, then the pulse feeding would have yielded even better results because there would have been less protein breakdown?

YB: Yes, exactly. Also, we have done other studies that focused on the splanchnic area, and we were surprised to see that in some conditions you can have a very high splanchnic extraction of the dietary amino acids coming from the diet. As you can imagine, having a slow or a fast protein or having a pulse or spread pattern may also affect the splanchnic utilization of amino acids and could therefore finally affect the amino acid availability to the peripheral tissue in the muscle. That’s what we have demonstrated previously. There are many considerations.


1 Arnal, M.A.; Mosoni, L.; Boirie, Y.; Houlier, M.L.; Morin, L.; Verdier, E.; Ritz, P.; Antoine, J.M.; Prugnaud, J.; Beaufrere, B.; Mirand, P.P. (1999). Protein pulse feeding improves protein retention in elderly women. American Journal of Clinical Nutrition. 69(6):1202-8.
2 Arnal, M.A.; Mosoni, L.; Boirie, Y.; Houlier, M.L.; Morin, L.; Verdier, E.; Ritz, P.; Antoine, J.M.; Prugnaud, J.; Beaufrere, B.; Mirand, P.P. (2000). Protein feeding pattern does not affect protein retention in young women. Journal of Nutrition. 130(7):1700-4.
3 Arnal, M.A.; Mosoni, L.; Boirie, Y.; Gachon, P.; Genest, M.; Bayle, G.; Grizard, J.; Arnal, M.; Antoine, J.M.; Beaufrere, B.; Mirand, P.P. (2000). Protein turnover modifications induced by the protein feeding pattern still persist after the end of the diets. American Journal of Physiology Endocrinology and Metabolism. 278(5):E902-9. IM

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