Much ado about protein

I doubt the Phoenix will man up and publish my rebuttal, so I’m gonna post this here. Because it pissed me off enough that I actually wrote a rebuttal.

Morgan Hunter’s article “How much protein powder should you actually consume?” in the September 22 print edition of the Phoenix is the kind of un-verified pseudo-science I would expect to see on the Misc forum of Bodybuilding.com, not in a student newspaper that theoretically has someone fact-checking their articles. [If there is no fact-checker, especially for science-type articles, maybe we need to vote them a bigger budget or something.]

First up, the things that are correct in the aforementioned article. The basic science mentioned in the second paragraph is correct, and the Dietary Reference Intake (DRI) has indeed been set by the Institute of Medicine of the U.S. National Academy of Sciences at 0.8 g/kg of bodyweight. Also, protein is indeed used by the body to help repair the muscles after a workout, and is also responsible for all sorts of magical other things that are not really relevant to this discussion.

Now, the DRI is a reasonable approximation of a basic place to start. However, the recommended values are based almost entirely on opinion, rather than actual scientific randomized controlled clinical trials [1]. So, they are at best an anecdotally derived suggestion, based on a statistical average. The main problem with that being that the average includes a large proportion of sedentary people who never lift anything heavier than a cheeseburger or a beer. Research has shown that the optimal range of daily protein intake for endurance athletes is in the 1.2-1.7 g/kg range , and for strength athletes is in the 1.2-2.2 g/kg range, with some research indicating benefits of intakes of up to 2.0 or 3.0 g/kg/day for endurance or strength athletes respectively [2].

Second, the 0.1 g/kg maximum of usable post-workout protein is a complete and utter fabrication. Sources, please? Real science done by real scientists in controlled conditions has shown that the maximum post-exercise protein absorption is 0.15 g/kg/hr [3]. That’s per HOUR kiddies, not the whole time ever after you work out. Based on a review of the relevant research, one author recommends a post-exercise protein intake dose of 0.55 g/kg (0.25g/lb) immediately following exercise (within 1-2 hours) [4]. This dose is supported by the research to stimulate the maximal net protein synthesis, and can be reduced by 50% for those not interested in maximal anabolic response, to economize total calorie intake or defer protein intake for another point. As a side note, for those requiring muscle glycogen refilling, research supports 1.2 g/kg/h for up to 5 hours post-exercise [5].

The body as pool analogy is just wrong and not in any way supported by research. Also, to quote Lyle McDonald (one of the leaders in the sports nutrition field, who happens to base all of his information on science) “the odds of protein being converted to fat in any quantitatively meaningful fashion is simply not going to happen” [6].

In summary; for optimal recovery after a hard workout, the current research suggests that one should consume 1.1 g/kg (0.5 g/lb) and 0.55 g/kg (0.25 g/lb) of bodyweight [4]. This is of course only if you are pushing hard in the gym and are actually causing stress to your muscles which requires recovering from. A good rule of thumb: if you haven’t broken a sweat during your workout, you probably don’t need very much in the way of post-workout nutrition.

Remember kiddies, nutrition is a science, and for the most part the mainstream media and other sources get it dead wrong at best, and wrong enough to hurt you at worst. Check their sources, don’t believe everything you read, including when you have read here. If you want solid, research- and evidence-based information, check out Alan Aragon’s Research Review [http://www.alanaragon.com/researchreview], or Lyle McDonald’s books and website [http://www.bodyrecomposition.com/].

[1] Sheffer, M, Taylor, CL. The Development of DRIs 1994–2004: Lessons Learned and New Challenges. Workshop Summary, November 30, 2007

[2] Tipton, KD, Wolfe RR. Protein and amino acids for athletes. J Sports Sci. 2004 Jan;22(1):65-79

[3] Rowlands DS, et al. Effect of dietary protein content during recovery from high-intensity cycling on subsequent performance and markers of stress, inflammation, and muscle damage in well-trained men. Appl Physiol Nutr Metab. 2008 Feb;33(1):39-51

[4] Aragon, A. Alan Aragon’s Research Review. March 2008.

[5] Stephens BR, et al. Effect of timing of energy and carbohydrate replacement on post-exercise insulin action. Appl Physiol Nutr Metab. 2007 Dec;32(6):1139-47

[6] http://www.bodyrecomposition.com/nutrition/excess-protein-and-fat-storage-qa.html/

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