Showing posts with label does. Show all posts
Showing posts with label does. Show all posts
Tuesday, March 8, 2016
It Does Matter How You Spread Your Protein Intake 30 Higher 24h Protein Synthesis with 30g Protein per Meal
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| Todays SuppVersity News will provide you with "confirmation" rather than "innovation", I suppose |
"...Influences 24-h Muscle Protein Synthesis in Healthy Adults"
By now, you may feel reminded of a recent review by Alan Aragon and Brad Schoenfeld (Aragon. 2013), the results of which (learn more) are not refuted by the results of the study at hand.
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| Avoid protein wasting post workout. |
In other words: Dont cram all your protein into one meal!
I guess in view of past articles on related topics (e.g. "2x40g, 4x20g or 8x10g of Whey? Which Feeding Strategy Yields the Greatest Net Protein Retention?" | read more; or "Protein Timing Reloaded: A Reminder on the Importance of Repeated 20g Pulses for Optimal Protein Synthesis" | read more), this insight is not really going to surprise you.
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| Figure 1: Fractional protein synthesis at breakfast (left), when the difference was most pronounced (+30%) and rel. calculated 24h fractional protein synthesis (right) with EVEN vs. SKEWED protein distribution (Mamerow. 2014) |
With an average age of 37 years the 8 healthy, normal-weight adult men and women who participated in the study at hand were neither rodents, nor elderly individuals, and - contrary to what you may expect if you look at the italicized names of the Institutions the scientists who were involved in this study are working at - they were not in need of rehabilitation after an injury - they were average Joes (n = 5) and Janes (n= 3).
This is not about rodents, elderly people or injured athletes
As you can see in the overview in Table 1, the subjects consumed three square meals, i.e. breakfast, lunch and dinner in the course of the 7-day study period. The previous reference to intermittent fasting is thus obsolete - eating a minimal amount of protein in the morning and at noon is after all very different from eating nothing at all.
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| Table 1: Seven-day mean energy and macronutrient intake in healthy adults consuming diets with an EVEN or SKEW protein distribution (Mamerow. 2014) |
"Both diets exceeded the RDA for protein [0.8 g/(kg d)] by ~50%. The SKEW diet met the RDA for protein during the evening meal alone. In all versions of the EVEN and SKEW menus used in this study, the animal-to-vegetable protein ratio was ~2:1." (Mamerow. 2014)By using a 7-d crossover feeding design with a 30-d washout period, the scientists were thus able to measure the influence of protein timing, on the changes in muscle protein synthesis.
The latter was measured thrice, i.e. after each of the three meals, and used to calculate the twenty-four-hour mixed muscle protein fractional synthesis rates on days 1 and 7 after the ingestion of EVEN-ly or SKEW-edly distributed protein diets.
| "Fat Loss Principles That Work: 10g+ of EAA W/ Every Meal" | read more |
In view of the fact that I gather that youd expected a result like this, I dont feel inclined to repeat that I have been suggesting for years to consume 30g+ of quality protein ("quality" = 10g+ of EAAs per 30g serving) with every meal.
If you stick to this simple principle, its going to help you build muscle and lose fat (see "Fat Loss Principles That Work: 10g+ of EAA W/ Every Meal" | read more).
- Aragon, Alan Albert, and Brad Jon Schoenfeld. "Nutrient timing revisited: is there a post-exercise anabolic window?." Journal of the International Society of Sports Nutrition 10.1 (2013): 5.
- Mamerow, Madonna M., et al. "Dietary Protein Distribution Positively Influences 24-h Muscle Protein Synthesis in Healthy Adults". J. Nutr. January 29, 2014 jn.113.185280 [ahead of print].
Monday, February 15, 2016
Time Under Tension TUT Random Numbers or Forgotten Determinant of Training Success What Does Science Say
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| "Go slow, grow fast" - does it really work this way? |
The methodological issues are probably also part of the reason that it would be an exaggeration to say that there are only "few" studies that investigate the influence of the time under tension (TUT) on hypertrophy or strength gains - but alas, I have collected the science-crumps for you. So here you go (for a preliminary list):
Low load + slow movement = high TUT ? increased protein synthesis -- The 175% increase in muscle protein synthesis in response to leg extensions that were performed with a TUT of 6s in the concentric, and 6s in the eccentric phase of the movement Nicholas A. Burd et al. report in their a 2012 paper in the Journal of Physiology is one of the is one of the few very concrete results from studies that were designed to isolate the effect of the time under tension (Burd. 2012).
Figure 1: Myofibrillar fractional protein synthesis (%/h; Burd. 2012)
In view of the pathetic load (30% of the 1RM) and the matched volume, the practical relevance of these figures is yet highly questionable. For me personally, it is thus more surprising that the difference between ...- doing 12, 7 and 6 reps @ 30% of the 1 rep max to failure for 198±10 s 119±9 and 90±7s, respectively (SLOW condition w/ TUT of 606), and
- performing the same number of reps with the same weight, this time obviously not to failure, within 25±2s, 14±1s, and 11±1s, respectively,
- Longer TUT, greater anaerobic energy expenditure - Inspite of the fact that it appears logical that longer times under tension would be associated with increases in energy expenditure, you as a SuppVersity reader know very well that not all things that exercise and nutrition science is not necessarily logical.
In view of the overall scarcity of literature it is thus more than worth mentioning that Christopher B. Scotts 2012 study into the effects of time-under-tension and weight lifting cadence on aerobic, anaerobic, and recovery energy expenditures found that both, the anaerobic (=glyoclytic) energy expenditure and post energy oxygen consumption (EPOC) were significantly increased, when you train with a cadence of 4:1 or 1:4 and a corresponding TUT of 25s instead of 1.5:1 (TUT = 15s).
It is thus only logical (you see, sometimes there is logic in exercise science ;-) that the total energy expenditure in the 25s TUT trials was ~30% higher than in the 15s TUT trial with its 1.5s up : 1.5 down cadence (see Figure 2).
Figure 2: Anaerobic energy expenditure, post exercise oxgen consumption and total energy expenditure (all in kJ) in the low TUT (1.5:1.5; 15s) vs. high TUT trials (Scott. 2012)
In view of the fact that the majority of us are hopefully not hitting the gym to "burn calories" (learn why thats simply dumb), these findings are interesting, but of similarly irrelevant as the previously cited increases in protein synthesis in the Burd study. - Concentric tension time is key to muscle growth -- I know that broscience dictates otherwise, but the evidence from a human study by Gillies, Putman & Bell suggests just that: Its the concentric portion of the exercise that stimulates skeletal muscle hypertrophy in response to leg presses, parallel squats, knee extensions and knee flexions in 28 healthy young women with previous strength training experience (Gillies. 2006).
As you can see in Figure 3, the baseline fibre size(s) of the subjects were yet so different that the participants that had been randomized to the group with an emphasis on the concentric phase (4:1 cadence) had an unfair growth advantage compared to the ladies in the eccentric emphasis group.
Figure 3: Fiber area (µm²) of type I & II fibers before and after the 9-week training intervention (Gillies. 2006)
In view of the fact that the eccentric emphasis group did also record greater strength gains, it appears unwarranted to change your training regimen from explosive / fast concentric vs. slow eccentric movements to the "concentric emphasis" pattern with its 4s : 1s cadence that was used in the study at hand. - Heavy and fast or "slow" and long - it does not even matter -- In 2006 and thus 6 years before the previously discussed study by Burd et al., Michiya Tanimoto and Naokata Ishii, two scientists from the University of Tokio conducted a similar, yet more realistic study which compared
a low-intensity training regimen [ 50% of onerepetition maximum (1RM)] with slow movement and tonic force generation (3 s for eccentric and concentric actions, 1-s pause, and no relaxing phase; LST), to a
Figure 4: Cross-sectional area of the knee extensor before (open bars) and after (solid bars) LST, HN, and LN exercise training for 12 wk (Tanimoto. 2006) - a high-intensity training regimen ( 80% 1RM) with normal speed (1 s for concentric and eccentric actions, 1 s for relaxing; HN), and
- a low-intensity with normal speed training regimen (same intensity as for LST and same speed as for HN; LN)
Bottom line: As a seasoned SuppVersity reader you should not need me to tell you that the data does not allow for a conclusive decision if (a) time under tension matters at all, and if so, if it may (b) actually be the main determinant of muscle growth.
I know at first that may sound hilarious, but if you think about the average bro in your gym who complains about "no gains", he will either be making tons of reps at a velocity that generates a momentum that reduces the TUT of an already fast 1-s rep to 0.1s, or he will tell you that only hitting it hard counts and his three reps on the bench press which are over in 6 seconds should actually make him grow.
To elucidate if (a) or (a) and (b) was right, we would yet need at least a dozen of well-designed studies, where - just as it was the case in the Burd study - the time under tension is the primary variable and reps, sets and weights only a means to modulate it. Until this data is available, it does probably not matter that I didnt have to dig up each and every article on that matter that exists... and if it did, I will just write another article ;-)
References: | The green dots are satellite cells, muscle precursors as they are built with high volume leg training | more |
To elucidate if (a) or (a) and (b) was right, we would yet need at least a dozen of well-designed studies, where - just as it was the case in the Burd study - the time under tension is the primary variable and reps, sets and weights only a means to modulate it. Until this data is available, it does probably not matter that I didnt have to dig up each and every article on that matter that exists... and if it did, I will just write another article ;-)
- Burd, N. A., Andrews, R. J., West, D. W., Little, J. P., Cochran, A. J., Hector, A. J., ... & Phillips, S. M. (2012). Muscle time under tension during resistance exercise stimulates differential muscle protein sub?fractional synthetic responses in men. The Journal of physiology, 590(2), 351-362.
- Gillies, E. M., Putman, C. T., & Bell, G. J. (2006). The effect of varying the time of concentric and eccentric muscle actions during resistance training on skeletal muscle adaptations in women. European journal of applied physiology, 97(4), 443-453.
- Scott, C. B. (2012). The effect of time-under-tension and weight lifting cadence on aerobic, anaerobic, and recovery energy expenditures: 3 submaximal sets. Applied Physiology, Nutrition, and Metabolism, 37(2), 252-256.
- Tanimoto, M., & Ishii, N. (2006). Effects of low-intensity resistance exercise with slow movement and tonic force generation on muscular function in young men. Journal of Applied Physiology, 100(4), 1150-1157.
Thursday, January 21, 2016
Does Your Pre Workout Inhibit Fat Loss Study Shows Nitrate Supplements Decrease Metabolic Rate By 4 2
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| If you want other to see your pump, you got to be ripped. If not, why care about reductions in BMR? |
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.
On a side note: I am pretty sure the fact that the other potential benefit is an increase in sexual stamina didnt hamper the sales either (Neuzillet, 2013; Hotta. 2014 ;-)
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
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| Figure 1: The Arginine- and the Nitrate-Nitrite - NO pathway are the yin and yan of nitric oxide production (Lundberg. 2008). |
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 nitratenitrite ? 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)
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| 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) |
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.
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| Suppversity Suggested Read: " The Beat Your Personal Bests W/ Beets 101: How Much? 8.4 mmol Nitrate ~400-1300g Beets! When? 2.5h Pre Workout!" | read more |
The way things are, I will refrain from ranting and rather suggest you simply skip the supps and consume the spinach, beetroot, lettuce and other high nitrate veggies right away. Most of the human studies which support the ergogenic potential of nitrates have been conducted with beetroot juice instead of capped sodium-nitrate.
And lets be honest, the weight loss advantage of having green and not so green nitrate containing vegetables in your is eventually beyond doubt. So, if there was a similar reduction in RMR from your daily serving of spinach, you can be more or less certain that it was compensated by the beneficial weight loss effects of the whole spectrum of nutrients thats present in this edible flowering plant in the family of Amaranthacea.
- 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 nitratenitritenitric 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.
Tuesday, January 19, 2016
Maximal Protein Synthesis in the Elderly How Much Protein Does it Take Another Study to Suggest More is Better!
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| 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. |
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.
You can learn more about protein intake at the SuppVersity

Are You Protein Wheysting?

5x More Than the FDA Allows!

Protein requ. of athletes
High EAA protein for fat loss
Fast vs. slow protein

Less Fat, More Muscle!
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| 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) |
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 810 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).
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| 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 (DSouza. 2014) |
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| 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 DSouza. 2014) |
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.
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| Suggested Read: "Protein Timing Does Matter! Yet Only in Trained Men. More Than 2x Higher Relative Protein Retention W/ Immediate vs. 6h Post Whey Consumption in Bodybuilders vs. Rookies" | read more. |
As mentioned in other recent posts, there are yet still many confounding variables that would have to be controlled and modified as well to answer the important (?) question: "How much protein does it take to achieve maximal post-workout protein synthesis?" Which confounding factors that would be? Well, what about the training experience? The baseline muscle mass? The protein content of the diet? And so on and so forth || Comment on Facebook!
- Burd, N. A., S. H. Gorissen, and L. J. van Loon. 2013. Anabolic resistance of muscle protein synthesis with aging. Exerc. Sport Sci. Rev. 41:169173.
- 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. 590:27512765.
- 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 40:199205.
- 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 45:231240. - 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. 99:276286. - 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. 19:422424.
- 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. 89:161168.
- West, D. W., and K. Baar. 2013. May the Force move you: TSC-ing the mechanical activation of mTOR. J. Physiol. 591:43694370.
- 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. 108:6067 .
- 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. 587:52395247.
- 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. 99:8695
- 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. 108:17801788.
- 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.
Sunday, January 10, 2016
PUFA Increases Postprandial Thermogenesis in Healthy Premenopausal Women Beyond 14 Increase Over MUFA SFA Sounds Huge But Does it Matter
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| Is there something to the good vs. bad fat shenanigan, after all? |
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!
You can learn more about fat at the SuppVersity

Are Men Fat- & Women Sugar-Cravers?

Fat, not Fructose Cons. Increased in the US
Adding Fats to Carbs Does not Reduce Insulin
The Forgotten Pro-Insulinogenic Effects of SFAs
Margarine Not Butter Incr. EU Waists
Low Fat to Blame for Low Vitamin D Epidemic?
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.
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| 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 PUFA-rich meal was base plus sunflower oil and flaxseed oil, with 42% of total energy coming from PUFA.
Table 1: Liquid meal nutrient composition
breakdown (Clevenger. 2014).
- 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.
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?
Now, does this increase in DIT matter? Westerterpet et al. who found a negative correlation between body fat levels and the diet induced thermogenesis in their 2008 study (Westerterpet al. 2008), certainly believe it matters. If we look at the total extra diet-induced energy expenditure in 5h after the test-meal in the study at hand, on the other hand, I cannot but ask myself, whether those 1.4kcal can actually make a difference.
I am not sure what you think, but considering the fact that you can burn those 1.4 extra calories in less than one minute in the gym, its hard to believe that the increased thermogenesis alone warrants the laymans conclusion that the study at hand would provide evidence for the superiority ot PUFAs over MUFAs and saturated fats ... what do you think?
References:I am not sure what you think, but considering the fact that you can burn those 1.4 extra calories in less than one minute in the gym, its hard to believe that the increased thermogenesis alone warrants the laymans conclusion that the study at hand would provide evidence for the superiority ot PUFAs over MUFAs and saturated fats ... what do you think?
- 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.
Monday, January 4, 2016
L Tryptophan is Reduced While Dieting Does This Make the Essential Amino Acid a Key to Succesfull Weight Loss
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| Trp and its metabolite 5-HTP may be particularly useful for female sugar cravings and binges. |
Honestly, fasting and eating / skipping breakfast may be more promising weight loss tools
Breakfast and Circadian Rhythm
Does Meal Timing Matter?
Breakfast & Glucose Metab.

Breaking the Fast, Cardio & the Brain

Does the Break- Fast-Myth Break?

Fasting = Muscle- Loss - Always?
"[...] has been shown to improve or prevent many of the aforementioned conditions. Bariatric surgical intervention in patients with adiposity was found not to improve tryptophan breakdown rates and other signs of immune activation and inflammation [4], whereas caloric restriction is known to be a strong activator of protective metabolic pathways, thereby leading to lower blood pressure, improved blood lipids, and reduced inflammatory markers, including CRP [9]. Still, little is known about the effects of an extreme short-term hypocaloric diet on Trp metabolism and changes in inflammatory biomarkers" (Strasser. 2014).The study Barbara Strasser, Ken Berger and Dietmar Fuchs conducted was thus designed to assess the effect of a 2-week caloric restriction weight loss diet on Trp breakdown, leptin, and inflammatory biomarkers in over weight adults.
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| Taking tons of BCAAs can deplete your brain Trp and serotonin and leave you tired and depressed. |
- a very low kcal diet group (VLCD; Ø 600 kcal/ day) and
- a low kcal diet group (LCD; Ø 1,200 kcal/day).
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| Figure 1: Changes in body composition pre- vs. post (Strasser. 2015). |
In contrast to what the researchers expected, both the Trp and Kyn concentrations decreased significantly by 21 and 16 % for VLCD and by 15 and 17 % for the LCD group, respectively, with no significant difference between groups. Practically speaking, this means that the ratio of Kyn/Trp concentrations did not change significantly in both groups."Data for biologic markers are shown in Table [1]. Fasting blood glucose declined significantly (P < 0.05) in the LCD group with no significant changes in insulin sensitivity in both groups after 2 weeks of caloric restriction. Weight loss diet lowered leptin levels in both groups, although not reaching the level of significance. Inflammatory biomarkers were not significantly altered during the trial, although there was a tendency toward an increase in IL-6 and TNF-a in the LCD group" (Strasser. 2015).
Table 1: Biologic markers before and after a 2-week very low kcal diet (VLCD) or low kcal die (LCD) in 38 overweight subjects (mean ± SD)
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| Adding 900mg 5-HTP to the diet of obese women helps them to reduce their energy intake significantly (Cangiano. 1992). |
"Trp concentrations decreased significantly with a caloric restriction weight loss diet, and lowest Trp concentrations were observed in the group of individuals with the lowest calorie intake." (Strasser. 2015)This reduction in Trp levels may well induce a disturbance in the biosynthesis of neurotransmitter 5-hydroxytryptamine (5-HT | Anderson. 1990), and appears to be associated with an increased susceptibility for depression (Widnet. 2002; Raison. 2009). Strasser et al. highlight:
Experiments in which Trp was acutely depleted (in many studies by administering BCAAs | see red boy) support this assumption. Young et al. (2013), for example, confirmed that the acute depletion of tryptophan will lead to low serotonin and subsequently lower mood and increased aggression, although results vary somewhat between studies with similar participants."Because Trp is precursor in various biochemical pathways, e.g., it is hydroxylated by tryptophan-5-hydroxylase (T5H) into the intermediate product 5-hydroxy-tryptophan, which by decarboxylation is further converted to neurotransmitter 5-HT (serotonin), and because substrate saturation of T5H is only about 50 % (Dantzer. 2011), changes in plasma Trp levels may have an immediate impact on brain serotonin levels" (Strasser. 2014).
Figure 2: The consumption of tryptophan-free amino acid supplements leads to highly significant increases in hunger ratings in healthy female subjects (Rieber. 2010).
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| Figure 3: Correlations between changes in tryp:LNAA ratio and appetite ratings (Gendall. 2000). |
Ah, and in case you are asking yourself why carbohydrate / sugar binges are a common consequence of low tryptophane:LNAA ratios, its important to know that increases in glucose and insulin in response to high carbohydrate meals will trigger an increase in brain tryptophan and serotonin synthesis (Benton. 2002). This is why the effects of low tryptophan or high LNAA (BCAA, tyrosine, phenylalanine) levels are more pronounced if you avoid dietary carbohydrates.
There is evidence of direct effects of serotonine on metabolic rate, but there is no evidence that the administration of Trp will induce similar increases in fatty acid oxidation and thermogenesis as serotonin (Le Feuvre. 1991; Cui. 1993). It does therefore remain speculative whether the use of tryptophan supplements will have beneficial effects on the success of your next diet that go beyond an increased ability to stick to your predetermined caloric deficit due to reduced hunger and (CHO) cravings. Furthermore its not 100% clear whether taking 5-HTP which is significantly closer to serotonin would have different and/or more pronounced beneficial effects compared to its precursor Trp.
This raises the question: Does supplementation help? Its one thing to observe correlations, its another thing to have scientific evidence from controlled trials which support a causative link between higher tryptophan intakes and/or supplementation and increased adherence to calorically restricted diets and/or reduced cravings and binges.
Lets take the study by Rieber et al. (2010 | Figure 2), for example, in their study a tryptophan-free amino acid supplement like the ones people sell as muscle builders lead to significant increases in hunger scores in healthy young women. Only recently, scientists from the University of Barcelona were able to show that chronic treatment with a tryptophan-rich protein hydrolysate improves emotional processing, mental energy levels and reaction time in middle-aged women. A result that suggests that chronic vs. acute treatments may have different effects, as well.
Direct evidence that tryptophan will also affect the reduction in energy expenditure, when dieting is yet not available from human trials. As of now, its thus the reduction in appetite and cravings that is furthermore particularly pronounced in women that may considered among the scientifically warranted benefits of tryptophan supplementation and the avoidance of tryptophan depleting Trp-free amino acid supplements containing BCAAs, phenylalanine and tyrosine | Comment on Facebook!
Lets take the study by Rieber et al. (2010 | Figure 2), for example, in their study a tryptophan-free amino acid supplement like the ones people sell as muscle builders lead to significant increases in hunger scores in healthy young women. Only recently, scientists from the University of Barcelona were able to show that chronic treatment with a tryptophan-rich protein hydrolysate improves emotional processing, mental energy levels and reaction time in middle-aged women. A result that suggests that chronic vs. acute treatments may have different effects, as well.
Direct evidence that tryptophan will also affect the reduction in energy expenditure, when dieting is yet not available from human trials. As of now, its thus the reduction in appetite and cravings that is furthermore particularly pronounced in women that may considered among the scientifically warranted benefits of tryptophan supplementation and the avoidance of tryptophan depleting Trp-free amino acid supplements containing BCAAs, phenylalanine and tyrosine | Comment on Facebook!
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