Dukan Diet

If you want other to see your pump, you got to be ripped. If not, why care about reductions in BMR?

If you remember my posts about the first generation, arginine-based pre-workout products you will be aware that the only pump they produced was the word "pump" in their name or product description. The reason was and still is simple. The mere provision of l-arginine, which is a precursor to nitric oxide does not lead to an increase in nitric oxide production. Why? Well, think of a building a house: Just buying some concrete wont make you a proud home owner, either ;-)

The bad thing: Arginine didnt work. The good thing: This means it didnt decrease your BMR, either

Against that background its quite astonishing that arginine and citrulline based pre-workout products have dominated the top-seller lists of the big supplement vendors for decades. A fact thats probably partly due to other potential benefits of these amino acids, of which one - you as a SuppVersity reader know that - could be fat loss | learn more about the potential fat loss effects.
With more and more people openly declaring that they would no longer waste money on "good tasting, but expensive and disfunctional products", they industry was yet pressed to develop alternatives. Luckily, our body has two options it can chose from, when producing nitric oxide.

Fortunately, the industry has developed better alternatives...?

You know option #1, the arginine ➲ nitric oxide pathway, and - with all the hype and hyperbole that surrounded the introduction of the first nitrate supplements - I am pretty sure, you know the other one as well, the nitrate-nitrite ➲ nitric oxide pathway

Figure 1: The Arginine- and the Nitrate-Nitrite - NO pathway are the yin and yan of nitric oxide production (Lundberg. 2008).

As the illustration (Figure 1) I have "borrowed" from a comment by Jon. O. Lundberg et al. (2008) illustrates quite nicely, the arginine and nitrite nitric oxide pathway are the yin and yan of NO production.

With the "yan", i.e. the nitrate-nitrite ➲ nitric oxide pathway being a relatively "new kid on the NO block", that recycles (=reduces) inorganic anions nitrate and nitrite to form bioactive NO in blood and tissues during physiological hypoxia.

It goes without saying that there is a bottle neck to this process as well, but the rate limiting availablility of oxygen which hampers the argine-based NO generation by NOS becomes limited as oxygen levels fall is actually a signal for the nitrate–nitrite ➲ nitric oxide to really kick in.

There is more yin and yan, here

If you take a closer look at the results of a study in the America Journal of Clinical Nutrition (Figure 2), you will yet have to realize that there is "more yin and yan", here than youd probably hope for. According to the data scientists from the venerable Karolinska Institutet in Stockholm, Sweden, present in their paper, "[d]ietary inorganic nitrate reduces the RMR." (Larsen. 2014)

Figure 2: VO2 consumption (marker of fatty acid oxidation) and basal metabolic rate (BMR) relative to means (left), thyroid hormone (T3, T4) levels after 3-d dietary intervention with sodium nitrate (Larsen. 2014)

Whut? Yes, you read Larsen et al. right: In their randomized, double-blind, crossover study, in the course of which the Swedish scientists measured the resting metabolic rate (RMR) of 13 perfectly healthy 18–49 y olds (17 women) via indirect calorimetry after a 3-d dietary intervention with sodium nitrate (NaNO3 @ 0.1mmol/kg body weight) or a placebo (NaCl), Larsen, Schiffer, Ekblom et al. observed a statistically and (probably) physiologically significant reduction BMR reduction of 4.2% which correlated strongly to the degree of nitrate accumulation in saliva (r²= 0.71) and fits in nicely with the reduced O2 consumption of which Bailey et al. were the first to observe it in response to nitrate supplementation during exercise (Bailey. 2009).

Interestingly, these effects were not - as you may have been speculated - brought about by changes in thyroid hormone status. And the subjects insulin sensitivity, glucose uptake, plasma concentration of isoprostanes, as well as their total antioxidant capacity were unaffected, as well.
Reference:

• Bailey, Stephen J., et al. "Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans." Journal of Applied Physiology 107.4 (2009): 1144-1155.
• Hotta, Yuji, et al. "Oral l‐citrulline supplementation improves erectile function and penile structure in castrated rats." International Journal of Urology (2014).
• Larsen, Filip J., et al. "Dietary inorganic nitrate improves mitochondrial efficiency in humans." Cell metabolism 13.2 (2011): 149-159.
• Lundberg, Jon O., Eddie Weitzberg, and Mark T. Gladwin. "The nitrate–nitrite–nitric oxide pathway in physiology and therapeutics." Nature Reviews Drug Discovery 7.2 (2008): 156-167.
• Neuzillet, Y., et al. "A randomized, double‐blind, crossover, placebo‐controlled comparative clinical trial of arginine aspartate plus adenosine monophosphate for the intermittent treatment of male erectile dysfunction." Andrology 1.2 (2013): 223-228.

Is there something to the good vs. bad fat shenanigan, after all?

Only recently scientists from the Texas Tech University report that a PUFA-rich high-fat meal led to a greater diet-induced thermogenesis in normal-weight premenopausal women compared with SFA- or MUFA-rich high-fat meals.

Reason enough to take a closer look at this and previous studies investigating the diet-induced thermogenic effects of PUFA-, MUFA- and SFA-rich meals and to conduct a reality check wrt to the question whether these differences actually matter - I mean, will you get and stay lean by upping your PUFA intake? Lets take a look!
In the initially mentioned study, Hui C. Clevenger, Amanda L. Kozimor, Chad M. Paton and Jamie A. Cooper explored the effect of three HF meals enriched with different fatty acids (MUFAs, PUFAs or SFAs) on metabolism in premenopausal women of normal weight. In that, the metabolic parameters of interest included postprandial energy expenditure (EE), which is then used to calculate DIT, and substrate oxidation, which included respiratory exchange ratio (RER), fat oxidation and carbohydrate (CHO) oxidation.

Based on previous research in men of normal weight, the Texas Tech researchers hypothesized that the diet induced thermogenesis (DIT) and fat oxidation would be the highest after the PUFA- and MUFA-rich meals and lowest after the SFA-rich meal in premenopausal women - a result of which you already know that it was only partly confirmed.

Figure 1: Diet-induced thermogenesis and respiratory exchange rate (higher RER = lower fatty acid oxidation vs. higher CHO oxidation) in the 5h after the test meal (Clevenger. 2014)

The data in Figure 1 does after all tell you that the expected MUFA-induced increase in diet-induced thermogenesis did not occur. PUFAs, on the other hand did the job, Clevenger et al. expected them to do. They increased the DIT by an ostensibly whopping 14% over the DIT the scientists observed in response to the ingestion of the high MUFA and SFA liquid meals that had been prepared with the same base of 8 fl oz (237 ml) of chocolate Ensure(R) with soy lecithin and Nesquik (R, but contained different additional dietary fatty acids added depending on the treatment condition:

• Table 1: Liquid meal nutrient composition breakdown (Clevenger. 2014).

  The PUFA-rich meal was ‘base’ plus sunflower oil and flaxseed oil, with 42% of total energy coming from PUFA.
   
• The MUFA-rich meal was ‘base’ plus canola oil and extra virgin olive oil, with 42% of total energy coming from MUFA.
  
  
• Finally, the SFA-rich meal was ‘base’ plus butter, coconut oil and palm oil, with 40% of total energy coming from SFA. 

As the data in Table 1 indicates, the nutrient profiles didnt differ much. The fatty acid composition, on the other hand did, with the SFA meal being the only one with measurable amounts of Butyric, Caprioc, Caprylic, Capric, Lauric, Myristic and Hepatedic acid. Fatty acids of which previous research indicate that they induces an obesity-linked proinflammatory gene expression profile in adipose tissue of subjects at risk of metabolic syndrome (van Dijk. 2009).

High MUFA diets, on the other hand, have been shown to potentiate the effects of weight loss in obese NIDDM patients (Low. 1996). They are the major group of fatty acids in the one oil, everyone appears to agree that its health (Olive oil). And last but not least, even the allegedly unhealthy omega-6s have been shown in randomized controlled to reduce liver fat and modestly improve metabolic status, without weight loss, when compared to high saturated fat diets (Bjermo. 2012).

All of these effects / this evidence could potentially be more important than the increase postprandial thermogenesis in the study at hand - so the ultimate question is: Does DIT even matter?
References:

• Bjermo, Helena, et al. "Effects of n− 6 PUFAs compared with SFAs on liver fat, lipoproteins, and inflammation in abdominal obesity: a randomized controlled trial." The American journal of clinical nutrition 95.5 (2012): 1003-1012.
• Clevenger, Hui C., et al. "Acute effect of dietary fatty acid composition on postprandial metabolism in women." Experimental physiology (2014): expphysiol-2013.
• Westerterp, Klaas R., et al. "Dietary fat oxidation as a function of body fat." The American journal of clinical nutrition 87.1 (2008): 132-135.

Maximal protein synthesis requires protein, but how much exactly you need will depend on your age - the older you are the more PWO protein youll need.

Scientists from the University of Auckland were fed up with the lack of information about the differential response in protein synthesis in response to the ingestion of various amounts of protein. Accordingly, Randall F. D’Souza et al. conducted a study to characterize the changes in intramuscular levels of EAAs and BCAAs and the expression of the "protein pump" p70S6K at Thr389, a marker of protein synthesis, in response to resistance exercise and graded ingestion of whey protein in older men.

As a regular SuppVersity reader you will probably already think: "Where is the actual measurement of the fractional protein synthesis?" The unfortunate answer: Its not there.
Previous research had show that the ingestion of graded amounts of high-quality protein such as whey after resistance will maximize with "only" 20g of egg protein (Moore. 2009) or whey (Witard. 2014) in young men. Multiple studies in older adults (>60 years), on the other hand, suggest that they exhibit a lower anabolic signaling and MPS response to protein feeding, resistance exercise, and the combination of feeding and exercise when compared to young men (Cuthbertson. 2005; Fry. 2011; Burd. 2013). Scientists call this phenomenon age-related "anabolic resistance" (Yang. 2012b).

Figure 1: In contrast to the fractional protein synthesis in the elderly, which increases with increasing amounts of protein, the FSR of young men shows a ceiling effect at 20g+ whey protein (Yang. 2012a; Moore. 2009)

As you can see in Figure 1 from a 2012 study by Yang, the same 20g of extra-whey (total dose 40g) that was useless in young men, lead to a significant increase in protein anabolism in elderly men. Compared to young men, the MPS response to feeding 40 g of protein was yet still slightly lower in older vs. count men (Yang. 2012a; Churchward Venne. 2013b).

What is particularly relevant for the study at hand, and the previously criticized absence of actual MPS measurements is the fact that deficits in feeding induced p70S6K phosphorylation may at least partially underpin anabolic resistance in aged skeletal muscle (Cuthbertson. 2005), which is why measuring the p70S6K phosphorylation in older human subjects (mean age 71 years) in response to the graded ingestion of whey protein after a leg workout consisting of three sets of 8–10 repetitions of bilateral barbell smith rack squat, 45°leg press, and seated knee extensions at 80% of the subjects predetermined 1R is not as irrelevant at it may initially have seemed.

Workout + supplements, thats the "whey to go" ;-)

The exercises were performed in a circuit manner with 1 min rest between each exercise and 3 min rest between subsequent sets, the exercise protocol took approximately 20 min to complete. Following completion of the exercise protocol, subjects were immediately provided with a fixed-volume (350 mL) beverage, containing a flavored noncaloric placebo, or oneof the four doses of whey protein concentrate (10 g, 20 g, 30 g, or 40 g).

Figure 2: Intramuscular amino acids. This figure is a heat map which shows groups means fold changes from the resting fasted condition. Green represents a decrease in amino acid content, white represents no change, and red represents an increase in amino acid content (D’Souza. 2014)

Subjects were instructed to ingest the beverage within 2 min and were required to ingest the total volume provided. Following consumption of the supplements, subjects rested in a supine position throughout the 4 h of post-exercise recovery with additional muscle biopsy samples collected at 2 and 4 h post exercise.

Figure 3: Higher protein intake = higher increase in p70S6K phosphorylation (left graph). This increase is linearly associated with intramuscular leucine levels (right graph | both from D’Souza. 2014)

As you can see in Figure 3, there was a similar dose-dependent increase in p70S6K as it was observed previously for MPS in skeletal muscle of elderly subjects by Yang et al. (2012b). In fact, the fold change in the phosphorylation of p70S6K (Thr389) at 2 h post exercise was correlated with the dose of whey protein consumed (r =0.51,P<001) and was found to be significantly correlated with intramuscular leucine content (r =0.32,P=0.026).

Moreover, the intramuscular BCAAs, and leucine in particular, appear to be important regulators of anabolic signaling in aged human muscle during post-exercise recovery via reversal of exercise-induced declines in intramuscular BCAAs.
References:

• Burd, N. A., S. H. Gorissen, and L. J. van Loon. 2013.  Anabolic resistance of muscle protein synthesis with aging. Exerc. Sport Sci. Rev. 41:169–173.
• Churchward-Venne, T. A., N. A. Burd, C. J. Mitchell, D. W. West, A. Philp, G. R. Marcotte, et al. 2012. Supplementation of a suboptimal protein dose with leucine or essential amino acids: effects on myofibrillar protein synthesis at rest and following resistance exercise in men. J. Physiol. 590:2751–2765.
• DSouza, Randall F., et al. 2014. Dose‐dependent increases in p70S6K phosphorylation and intramuscular branched‐chain amino acids in older men following resistance exercise and protein intake. Physiological Reports 2.8: e12112.
• Churchward-Venne, T. A., L. Breen, and S. M. Phillips. 2013a. Alterations in human muscle protein metabolism with aging: protein and exercise as countermeasures to offset sarcopenia. BioFactors 40:199–205.
• Churchward-Venne, T. A., C. H. Murphy, T. M. Longland, and S. M. Phillips. 2013b. Role of protein and amino acids in promoting lean mass accretion with resistance exercise
  and attenuating lean mass loss during energy deficit in humans. Amino Acids 45:231–240.
• Churchward-Venne, T. A., L. Breen, D. M. Di Donato, A. J. Hector, C. J. Mitchell, D. R. Moore, et al. 2014. Leucine supplementation of a low-protein mixed macronutrient beverage enhances myofibrillar protein synthesis in young men: a double-blind, randomized trial.
  Am. J. Clin. Nutr. 99:276–286.
• Cuthbertson, D., K. Smith, J. Babraj, G. Leese, T. Waddell, P. Atherton, et al. 2005. Anabolic signaling deficits underlie amino acid resistance of wasting, aging muscle. FASEB J. 19:422–424.
• Moore, D. R., M. J. Robinson, J. L. Fry, J. E. Tang, E. I. Glover, S. B. Wilkinson, et al. 2009. Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Am. J. Clin. Nutr. 89:161–168.
• West, D. W., and K. Baar. 2013. May the Force move you: TSC-ing the mechanical activation of mTOR. J. Physiol. 591:4369–4370.
• West, D. W., N. A. Burd, J. E. Tang, D. R. Moore, A. W. Staples, A. M. Holwerda, et al. 2009a. Elevations in ostensibly anabolic hormones with resistance exercise enhance neither training-induced muscle hypertrophy nor strength of the elbow flexors. J. Appl. Physiol. 108:60–67 .
• West, D. W., G. W. Kujbida, D. R. Moore, P. Atherton, N. A. Burd, J. P. Padzik, et al. 2009b. Resistance exercise-induced increases in putative anabolic hormones do not enhance muscle protein synthesis or intracellular signalling in young men. J. Physiol. 587:5239–5247.
• Witard, O. C., S. R. Jackman, L. Breen, K. Smith, A. Selby, and K. D. Tipton. 2014. Myofibrillar muscle protein synthesis rates subsequent to a meal in response to increasing doses of whey protein at rest and after resistance exercise. Am. J. Clin. Nutr. 99:86–95
• Yang, Y., L. Breen, N. A. Burd, A. J. Hector, T. A. Churchward-Venne, A. R. Josse, et al. 2012a. Resistance exercise enhances myofibrillar protein synthesis with graded intakes of whey protein in older men. Br. J. Nutr. 108:1780–1788.
• Yang, Y., T. A. Churchward-Venne, N. A. Burd, L. Breen, M. A. Tarnopolsky, and S. M. Phillips. 2012b. Myofibrillar protein synthesis following ingestion of soy protein isolate at rest and after resistance exercise in elderly men. Nutr. Metab. 9:57.

You as a SuppVersity reader should know that there is no "instant gratification" with  "doing cardio" and that doing it "in the zone" is totally 90s... 1990s, even ;-)

For decades, the "Fat Burning Zone" has been one of the holy grails of exercise sciences. Then somebody realized that maximizing the ratio of fat : glucose thats are being used as fuel during a workout doesnt really have an effect on weight loss and all of a sudden papers with titles like "Changes in peak fat oxidation in response to different doses of endurance training" (Rosenkilde. 2013) have become a rarity... although, if you look closely, you will realize that this is actually not another investigation into the realms of the "Fat Burning Zone", but an afford to quantify the effect of regular "cardio training" on your bodies ability to oxidize fat, instead of glucose.

Dont worry its not really about the "fat burning zone"

Luckily Rosenkildes most recent paper, which happens to be the third spinoff of the high (600kcal/day) vs. medium (300kcal/day energy expenditure from "cardio") training volume that already taught us (you can read more about the exact exercise protocol in the previous SuppVersity articles, below) ...

• Learn more about the "Fallacy of Working Out To Burn Calories"

  how futile it is to work out like a maniac if fat loss is your goal ("Some HIIT For Life & Less LISS For More! How to Burn 27,300 Kcal Extra W/out Losing a Single Extra Pound of Fat!" | read more) and 
• how messed up the die hard belief that "exercise" just makes you hungry actually is and what the effects of endurance exercise on appetite and energy intake are ("Exercise: Does It Really Make You Hungry? The More You Train, The Less Hungry You Are." | read more)

In this second serving of the data, we can now learn whether regular endurance training increases peak fat oxidation in a dose-dependent fashion.

Figure 1: Pre & post respiratory exchange ratio (lower value = higher ratio of fatty acid : glucose oxidation) in sedentary control and 300kcal/day group, left; changes in the expression of mitochondrial enzymes (Rosenkilde. 2013)

As you can see in Figure 1 the outcomes of the experiment were not exactly surprising: While there was a persistent increase in fatty acid oxidation and the expression of the facilitative mitochondrial complexes, i.e. enzymes in the mitochondrial respiratory chain, the daily endurance training volume (MOD: 300kcal/day vs. HIGH: 600kcal/day energy expenditure during endurance training) had no effect on the effect size.

So, if its not the volume, what determines the increase in fatty acid oxidation?

Rosenkilde have probably asked themselves something similar to the above, when they realized that there were no meaningful differences between the subjects in the medium vs. high dose cardio groups. The statistical analyses the researcher conducted did yet reveal, that

• VO2peak, generally regarded as a marker of cardio-respiratory fitness,
• fat free mass, the weight of everything (incl. bones, organs, etc.) thats not fat, 
• cycling efficiency, the power output at a given VO2 peak, and the
• mitochondrial complexes II–V, enzymes that facilitate the oxidation of fatty acids,

were all associated with higher increases in fatty acid oxidation, while the observed changes in fasting plasma insulin, glucose, FFA, or glycerol had no prognostic value with respect to the increase in fatty acid oxidation.
References: 

• Crane, J. D., MacNeil, L. G., & Tarnopolsky, M. A. (2013). Long-term Aerobic Exercise Is Associated With Greater Muscle Strength Throughout the Life Span. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 68(6), 631-638.
• Harber, M. P., Konopka, A. R., Douglass, M. D., Minchev, K., Kaminsky, L. A., Trappe, T. A., & Trappe, S. (2009). Aerobic exercise training improves whole muscle and single myofiber size and function in older women. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 297(5), R1452-R1459.
• Ozaki, H., Loenneke, J. P., Thiebaud, R. S., Stager, J. M., & Abe, T. (2013). Possibility of leg muscle hypertrophy by ambulation in older adults: a brief review. Clinical interventions in aging, 8, 369.
• Rosenkilde, M., Reichkendler, M. H., Auerbach, P., Bonne, T. C., Sjödin, A., Ploug, T., & Stallknecht, B. M. (2014). Changes in peak fat oxidation in response to different doses of endurance training. Scandinavian Journal of Medicine & Science in Sports.