Saturday, August 31, 2013

Leucine + B6: 82% More Weight + Twice As Much Body Fat Loss in First 12 of 24 Weeks on -500kcal/day Diet W/ 2.25g Leucine + 30mg Pyridoxine - To Good to Be True?

Check your nutrition labels, I bet you get 2.25g+ leucine and 30mg of B6 from one of your supps already
I am sorry to say that and actually this is usually something that goes into the bottom line, but I do have serious doubts whether the results reported in this study can be replicated in any of you. Yes, it is a human study, but (a) the subjects, 12 men and 12 women, were obese (34.76 ± 2.57) and (b) if the mere addition of 2.25 g leucine and 30 mg vitamin B6 would have such profound effects, everyone who has ever taken a commercial BCAA product would have noticed a doubling in fat loss, already, as almost all of them contain 2.25g+ of leucine and tons of pyridoxine (B6).

So what are you saying here? Is this study a fraud?

I have no evidence that the study was a fraud and I am certainly not implying this, but you must wonder about the magnitude of the weight loss and fat loss difference between the regular and the NuShape supplemented dieters (-500kcal from baseline energy demands calculated simplistically by  1.3× result of the WHO formula for basal metabolic rate), who ingested 2x 1.125 g leucine and 15 mg pyridoxine per day (whether that's on empty is not disclosed in the paper).
Figure 1: Changes in insulin (μU/ml), HOMA-IR, waist circumference (cm), body weight (kg), fat weight (kg) after 12 (blue) and 24 weeks (orange), relative change from 12-24 weeks is indicated in % below the bars (Zemel. 2013)
According to the researchers, who have published corresponding data for rodents and an analysis of the effects of the same combination of leucine + pyridoxine on total fat oxidation (>30g increase per day in a randomized controlled study; Zemel. 2012), the specific effects on visceral obesity could be a result of the
"reductions of oxidative and inflammatory stress biomarkers, such as plasma malondialdehyde (MDA), 8- isoprostane F-2α, tumor necrosis factor-α, and C-reactive protein, as well as an increase in the anti-inflammatory marker adiponectin" (Zemel. 2013)
they observed in a previous trial after 4 weeks, even in the absence of weight loss (Zemel. 2012). This would certainly be beneficial for both the lean and the fat individual, but with already low levels of CRP, MDA and TNF-alpha as you, as a healthy follower of physical culture should have them, these changes will be so small that they are unlikely to have any visible effects on you.

There decreased weight / waist / fat loss within the 2nd two weeks in the supplement group (see figure 1, yellow arrow for the discussion of waist circumference as an example) does actually provide evidence that the effect size will decrease the learner you are... even "worse", but rather hypothetical: The effect could also be diminishing, because the human body get's used to the new steady influx of leucine and B6 and their beneficial effects on the mitochondria, Sirt-1 and AMPK expression (learn more; note: as stated in this older article of mine, it works also without resveratrol)

Learn more about leucine, HMB, B6, mitochondrial health and weight / fat loss in a previous post (read more)
Bottom line: You are probably already doing what 50% of the subjects in this (sponsored) study have been randomly assigned to, i.e. consuming an extra 2.25g of leucine and 30mg of vitamin B6 (this is ~3800% of the RDA) per day if you consume either a "sports multi", a "high potency B-vitamin" or simply the next best BCAA or other amino acid / protein product with added B6. So, let me ask you a question, then. Did you get ripped to the shreds from this practice? No? Well, in that case you will probably share my doubts about the relevance of the data and the usefulness of the said supplement.

  • Zemel MB, Bruckbauer A. Effects of a leucine and pyridoxine- containing nutraceutical on fat oxidation, and oxidative and inflammatory stress in overweight and obese subjects. Nutrients. 2012;4:529–541
  • Zemel MB, Bruckbauer A. Effects of a leucine and pyridoxine-containing nutraceutical on body weight and composition in obese subjects. Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy. 22 August 2013.