Thursday, October 18, 2012

2x40g, 4x20g or 8x10g of Whey? Which Feeding Strategy Yields the Greatest Net Protein Retention? Plus: What the Results Can Tell Us About Intermittent Fasting on a "Bulk"

In know, after reading the headline you are probably already urgently waiting for the results of the latest study on protein timing, but before we get to the facts, let me briefly announce that this "bolus vs. intermittent vs. pulse" protein study, which is incidentally the result of an international cooperation between researchers from the Nestlé Research Centre in Lausanne, Switzerland, Canadian researchers from the University of Guelph, the Canadian Sport Centre and (you guessed it) Stuart M Phillips' group at the McMaster University, and their colleagues from the Australian Institute of Sport and the RMIT University in Melbourne, will be one of the topics of today's SuppVersity Science Round Up on Super Human Radio.

Other things I hope Carl Lanore and I will be able to squeeze into today's show, which airs, just as every Thursday live at 1PM EST and will also be available as a podcast later today, either right from the nav-bar on the right ("Physical Culture for Your Ears") or at, are ...
  • the latest news on natural nitrate supplementation with beet root juice, 
  • how stress and laziness increase breast cancer risk more than hormonal imbalances, and
  • how you can prepare your own powerful stevia-based wound ointment  
There is obviously more to the list, but I have learned from past mistakes and won't announce all I have piled up, when I know that's simply not possible to squeeze all of them into a single 1h show ;-)
A note for those of you who are looking for Adelfo Cerame's weekly contest prep blog: Don't worry it's still alive! You must have over-read that he has switched to a bi-monthly format!
Ok, ok... but NOW tell me hod do I have to spread my protein across the day"

While we know already that more is not necessarily better, when it comes to protein intake and that timing plays a significant role with respect to the returns in protein synthesis, and more importantly net protein retention you get for each gram of additional protein you consume, the question how you best spread your roughly 1.5-2.0g of protein per kg body weight across the day is still a matter of contemporary research and bro-scientific debate.

Suggested read: Protein Synthesis "Beyond the 20g Limit: Study Shows Exercise Facilitates 32% Greater Increases in Fractional Protein Synthesis With 40g vs. of 20g of Whey PWO" (click here to read)
What appears to be widely accepted, though, is the notion that both, the ingestion of a slow digesting protein before, and the intake of a fast digesting protein after a workout can effectively increase protein synthesis and net protein retention. If we assume that the combination of both strategies will yield further benefits (this has to my knowledge not been shown yet and is certainly not necessarly the case!), and regard the peri-workout supplementation as a "stand alone" that's not part of the 1.5g-2.0g /kg body weight baseline protein intake, we still end up with at least 80g of high quality protein (for the real light-weights or ladies ;-) we would have to spread in one way or another across the rest of the day.

8 x 10g, 4 x 20g or 2 x 40g? What's "optimal"?

Now, Moore et al. obviously won't have had my allegedly botchy "real-world" scenario on their minds, when they came up with the exact experimental design of their latest study. Still, if we forget about the 20g+ of protein post-workout, I believe none of you will be willing to abandon, their experimental setup fits the framework pretty nicely. After all, the scientists deliberately picked the 12h period after a workout "to standardise and take advantage of the accentuated protein synthesis in the exercised muscle over this period" and investigate three archetypal means of spreading a total amount of 80g of protein across the day: In 2 x 40g servings, 4x 20g servings or 8x 10g serving (Moore. 2012).

Suggested read: "3.2kg of Lean Mass Over Night W/ 40g of Slow Digesting Protein 30min Before Bed!?" (click here to read more)
The 24 male subjects who were advanced trainees working out 4–6 times per week in what the researchers call a "high intensity resistance training regimen" (note: I don't think this denotes a classic low volume HIT regimen) had to
"[...] follow standardized diet for the 72h prior to the trial that provided an energy availability of 45 kcal/kg fat-free mass with a macronutrient contribution 1.5 g protein/kg/d and 4 g carbohydrate/kg/d, respectively. [Moreover, s]ubjects were instructed to refrain from training and other vigorous physical activity during the 72h period."
When the men reported to the laboratory on the testing day, they had refrained from training or performing any other vigorous activity during the 72h period leading to the intervention and had been fasting 10h (over night). In absence of any other information I assume they remained in the fasted state for the subsequent standardized acute bilateral leg extension exercise session (4x10 sets at 80% 1-RM with 3 min recovery between sets), after which they were randomly allocated to receive their 80g of protein from whey as
  • pulsed feeding (PULSE), 8x10g every 1.5h; 
  • intermediate feeding (INT), 4x20g every 3h ; or 
  • bolus feeding (BOLUS), 2x40g every 6h. 
The supplementation regimen was started right after the workout and the protein synthesis, breakdown and net balance were determined based on previously tested and verified procedures (Hartmann. 2006).
Figure 1: Comparison of effect sizes, p-values (remember only p < 0.05 would be a statistical significant difference) and the scientists qualitative inference's based on the effect of feeding pattern on whole body net protein balance (left) and a detailed breakdown of the feeding specific effects on 12h protein synthesis expressed relative to the bolus group (based on data from Moore. 2012)
As the data in figure 1 goes to show you, the results clearly confirm that the pattern according to which you consume your daily allotment of protein does matter, what it does yet not really tell us is how this will translate into a real-world scenario, in which, as I have pointed out before, not having at least 20g of whey / other protein sources after a workout appears almost negligent. The provision of a 20g whey + 10g casein mix right after a workout could, for example, have undone the minimal (and statistically non-significant) advantage in net protein retention of the intermediate feeding group. And that may still have been the case if the latter had been "upgraded"  to a 4x25g whey pattern.

On the other hand, if we wanted to pick on the study design, the "workout" (leg extension) and the absence of other nutrients (or the lack of information about those in the paper?), which could easily have reduced the amino acid breakdown that nullified the advantage the pulse feeding had with respect to its ability to trigger and sustain (over 12h) protein synthesis, would be more relevant points of critique, anyway. That said the "study" at hand is actually only a "short communication", and I am pretty sure there is more to come in the future (it stands to reason that the SuppVersity is the place to go to read about that, right?)

Note: I still maintain that overnight fasting is healthy, and IF probably one of the best, r at least a very effective way to shed body fat, but that does not mean that it should be the only diet strategy in your "nutritional toolbox", in which other tools are probably better suited to pack on slabs of muscle!
(Preliminary) bottom line: The results Moore et al. present certainly don't provide a definitive answer on "the very best" way to time your protein intake (and even if there was an "optimal" way, no single study will ever be able to elucidate it). They do however make one thing pretty clear: My gut feeling that intermittent fasting and here especially those varieties with very long fasting and very short feeding windows, is probably not the best way of dieting to gain muscle. After all, there is no debating that the bolus regimen (2x40g 6h apart!) is trailing behind.

You can certainly tweak and thus optimize it by (a) adding a third meal in between and (b) cleverly using / combining fast and slow acting proteins (cf. "Whey and Casein Work Hand in Hand for Protein Anabolism"), but if you want level playing fields you would have to apply similar tweaks to the more frequent 4 x 20g and 8x 10g regimen as well... and I that would probably restore, if not magnify the difference.
Update on the real world significance of the advantage: I know that SuppVersity readers are smart and therefore was not suprised that only minutes after I posted this article, Steven Arcera objected that long-term studies don't show this advantage. Now, while Steven is right the implicit assumption that this implies that there is no advantage of spreading your protein across meals is false. If we simply take the exact figures from the study, which would be an added ~0.02g/kg body weight in protein retention over 12h, assume (which is obviously not valid) that the protein retention would be identical over the other 12h of the day in all groups and do the math for the study participants who weighed 80kg, this would be an additional 1.6g of protein retention for the whole body (remember this is whole body protein retention) and therfore even in a long-term study of 12 weeks only 134.4g! This would still be 134.4g more than with bolus feeding but would NEVER make a statistical significant difference in any study. And even the 584g "advantage" you would accumulate over a whole year would make it past the p < 0.05 line! So much about "optimal feeding strategies" and the real world outcomes of the latter :-)

  • Hartman JW, Moore DR, Phillips SM. Resistance training reduces whole-body protein turnover and improves net protein retention in untrained young males. Appl Physiol Nutr Metab. 2006 Oct;31(5):557-64.
  • Moore DR, Areta J, Coffey VG, Stellingwerff T, Phillips SM, Burke LM, ClĂ©roux M, Godin JP, Hawley JA. Daytime pattern of post-exercise protein intake affects whole-body protein turnover in resistance-trained males. Nutr Metab (Lond). 2012 Oct 16;9(1):91.