Showing posts with label weight loss. Show all posts
Showing posts with label weight loss. Show all posts

Tuesday, April 12, 2011

Calorie Restriction vs. Exercise for Optimal Body Composition? Exercise Preserves Muscle Tissue and Prevents Metabolic Downregulation.

Those of you who listened to my comments on set points and reasonable weight loss on Super Human Radio, will already know that - other than Gary Taubes, for example - I am a huge advocate of exercise, when it comes to weight loss, -maintenance and overall improvements in body composition. Data from a recently published study (Soare. 2011), despite being evaluated from an anti-aging perspective, confirms the adequacy of approaching your body composition goals, by dietary modifications and exercise induced increases in energy expenditure, instead of just "eating less calories".

In their study, Soare et al compared 24 subjects who had been on a calorically restricted diet (CR, 1769±348 kcal/d) for an average of 6 years to 24 age- and sex-matched sedentary individuals (control, WD, 2302±668 kcal/d) and 24 body fat-matched exercise-trained (EX, 2798±760 kcal/d) volunteers, who were eating Western diets.
Figure 1: Total body weight, lean mass & fat mass in sendentary control, calorie restricted (CR) and exercise (EX) group. (Data adapted from Soare. 2011)

Although the researchers found that both, "the CR and EX groups were significantly leaner than the control (WD) group" both the greater amount of lean body mass (cf. figure 1) as well as their finding that...
Mean 24-hour, day-time and night-time core body temperatures were all significantly lower in the CR group than in the WD and EX groups (P≤0.01).
...underline the futility of every effort to achieve improved body composition, i.e, to maximize muscle (lean mass), while shedding as much body fat, as possible via (even moderate) caloric restriction.

Two other things are noteworthy, as well. Firstly, the reduction in body temperature, which is indicative of a downregulation of the metabolic rate, may be favorable for a longer, but that does not equate into more livable life. And secondly, the "Taubes-Hypothesis" that exercise is "useless", because "it makes you hungry" (the subjects in the EX group in fact consumed more calories) and you would compensate by eating more, anyway, would be relevant, only, if in fact "a calorie was a calorie" and "only calories" counted; the superior body composition of the exercise group, on the other hand, speaks for itself and does suggest that even Garry himself may benefit from one or another training session in the gym ;-)

Edit: As I hear in an anonymous comment Taubes is supposed to do resistance training. When he was talking to doctor Oz, he did however propose the hypothesis I refer to above and this really bothered me.

Wednesday, March 30, 2011

An Old Dog Learns New Tricks: "Fatloss Fat" Tetradecylthioacetic Acid (TTA) Cardioprotective in Diabetic Rats

Do you remember the acronym TTA? Tetradecylthioacetic Acid? No. Well, I guess then you were not into fat burners in the early 2000s. TTA, a thia-fatty acid, was all the rage back in the day: Supplement producers claimed it would literally melt fat away and it actually turned out that some users had outstanding results megadosing respective supplements. Others, however, got bloated and/or started cramping. In view of these nasty side effects, most companies decided to reformulate their products and - with the exception of a few so-called "non-thermogenic" fat burners - TTA has almost disappeared from the market.

An international team of scientists from Norway and Canada (Khalid. 2011) has now discovered that the artificial fatty acid tetradecylthioacetic acid, which was originally intended as a drug for the treatment of the metabolic syndrome, might have the potential to protect type II diabetics from heart attacks.
In a previous study (Hafstad. 2009) the scientists had already shown that TTA does increase myocardial fatty acid oxidation in normal mice, a finding that would generally suggest impaired cardiac efficiency and thus be considered detrimental. In the current study on hyperlipidemic [high blood lipid levels] type 2 diabetic mice, however, TTA-treatment (0.5%, 8 days) had almost opposite effects on on cardiac metabolism and function
We found that TTA treatment increased myocardial FA oxidation, not only in non-diabetic (db/+) mice, but also in diabetic (db/db) mice, despite a clear lipid-lowering effect. While TTA had deleterious effects in hearts from non-diabetic mice (decreased efficiency and impaired mitochondrial respiratory capacity), these effects were not observed in db/db hearts. In db/db hearts TTA improved ischemic tolerance, an effect that is most likely related to TTA's antioxidant property.
Being a specifically designed (Pan-)PPAR-ligand [TTA seems to activate all PPAR-receptors] the lipid lowering effect of TTA was to be expected. The differential effect on heart function in healthy and diabetic rats, however, comes as a surprise and reminds us, again, that not all that has been shown to help sick people is beneficial - and sometimes its not even safe! - for the healthy part of the population.
Figure 1: Myocardial fatty acid and glucose oxidation in hearts of db/+ (white  545
bars) and db/db (gray bars) mice. Results are mean of 8-9 hearts in each group. (Khalid. 2011)
So, regardless how promising the shift in substrate metabolism from carbohydrates to fats, as it is visualized in figure 1 may appear, if you just want to shed a few pounds of unaesthetic, but healthy subcutaneous body fat, stay away from tetradecylthioacetic acid - for your heart's sake!

Tuesday, March 29, 2011

ProfDrAndro @ Super Human Radio: Set to Be Obese? Of Set & Settle Points on Your Way to a Super Human Physique

Just in case you got nothing else to do: Tune in live and listen to some more (probably Carl) or less (probably me ;-) intelligent Supp-Talk on Carl Lenore's Super Human Radio!

Topic: Set & settle points and how contemporary science
may contribute & explain your personal weight loss success


Listen live @ 9:00AM AM/12:00PM ET

Tuesday, March 22, 2011

Protein's Effects on Gene Expression: Higher Protein Lower Carbohydrate Diet Spares Gylcogen, Lowers Insulin and Reduces Lipogenesis

High protein diets have become the "gold standard" within the fitness community. On the countless bodybuilding, fitness and weight loss related bulletin boards on the Internet, athletes, gymrats and even overweight house-wives report outstanding benefits of a higher than normal protein intake on weight gain and/or fat loss. French scientists (Stepien. 2011) have now taken a closer look at the mechanism behind these success stories and found a strong (epi)genetic component (for an introduction to epigenetics, I recommend listening to Dr Rouse's interview series on Carl Lenore's Super Human Radio).
 Figure 1: Effect of high protein diet on genes regulating lipogenesis [lipo = fat; genesis = production] in the liver (Stepien. 2011)
Stepien et al. fed 80 male winstar rats either a normal or a high protein (50% protein) diet for 1,3,6 or 14 days and evaluated the mRNA levels [indicators of how active these genes are] of genes "involved in carbohydrate and lipid metabolism", energy expenditure (EE) and substrate oxidation, as well as liver glycogen, plasma glucose and hormones. What they observed stands in line with the positive anecdotal evidence you will find if you google muscle gain or fat loss "success stories":
    In liver, HP feeding 1) decreased mRNA encoding glycolysis enzymes (GK, L-PK) and lipogenesis enzymes(ACC, FAS), 2) increased mRNA encoding gluconeogenesis enzymes (PEPCK), 3) first lowered, then restored mRNA encoding glycogen synthesis enzyme (GS), 4) did not change mRNA encoding b-oxidation enzymes (CPT1, ACOX1, bHAD).
So, interestingly, with the exception of the 1st day of the experiment (where the increase in protein intake resulted in a short-term increase in fat oxidation), fat oxidation was stable (cf. 4) The "fat burning" effect, which is often ascribed to high protein diets, thus is not existent - or let's say its not a direct one, but a result of the synergy of other genetic and metabolic adaptations and the calorie restriction all weight loss regimens have in common.
Figure 2: Postprandial macronutrient balance as assessed during a 4 h period after the intake of a calibrated meal consisting of 4 g of an adequate diet.  (Stepien. 2011)
Here is where the insulin lowering effect, the reduced hepatic glucose uptake and the reduction in lipogenesis (cf. fig. 1) come into play. Combined with an overall increase in postprandial energy expenditure (observed only under long term high protein feeding conditions, cf. fig 2, HP14) and a slight but significant increase in the percentage of fat (LOX, fig. 2) that is used to fuel these demands, these genetic and metabolic adaption (most prominently the lower insulin levels and the reduction in lipogenesis) are the most probable mechanisms to explain the reduced fat gains and increases in fat loss on high protein weight gain and weight loss diets, respectively.

Sunday, March 20, 2011

Supplemental (!) Coconut Diet Reduces Waist Circumference in Men more Than in Women While Leaving Lipid Profiles Unchanged

I take the recent New York Times Article on coconut oil as clear evidence of the fact that the health benefit of tropical oils is getting more and more public attention. Studies that establish the many anecdotal reports you can find all over the Internet may even speed up this process and thus I am happy to report the findings of a Malasian study (Liau. 2011) that clearly underlines that the "bad" saturated fat cannot be so "bad" after all.

The scientists had a group of 20 healthy, but obese Malay volunteers consume an additional 30 mL of coconut oil (approx 2 tablespoons) per day taken in three divided doses, half an hour before each meal (as far as digestive side effects are concerned, this was the best tolerated dose as assessed before the actual study) and found...
that only waist circumference [WC] was significantly reduced after one month of VCO with a mean reduction of 2.87 +/-4.95 cm.
The high standard deviation of this data may well be attributed to the fact that there was no additional control of the dietary habits of the volunteers. The study says subjects "continued their weight loss efforts", but you probably know these "efforts" often turn out to be hardly comparable. I also feel that the real-world significance of the scientists statistical assessment "WC reduction was only seen in males" must be reevaluated, especially in view of the fact that "the reduction [meaning in cm WC] was larger in females" and the reduction in females with BMI <30 (4.8 +/-6.1 cm), other than in females with BMI >30 2.61 +/-2.17) was statistically significant (for more data cf. figure 1).
Figure 1: Comparison of mean differences in anthropometric measurements and lipid profile values in 7 males and 13 females after VCO consumption. (Liau. 2011)
I refrain from commenting on the reasons and invite readers to come up with their own theories, why someone who has gotten to a BMI of >30 (!!) may have problems losing weight on an uncontrolled intervention. What this should tell you, however, is that you may safely assume that 2 x tablespoons of coconut oil (~30ml) à day may be a worthwhile addition to your well-planned diet & exercise regimen.

On a side note: Who knows how much centimeters the volunteers had lost if the had just replaced some of the "good" seed oils in their diets? Well, I guess in view of the fact that the scientists seemed surprised that the bad saturated fats in coconut oil did not ruin their volunteers fatty acid profiles, they probably considered it unethical to ask their participants to completely replace corn with coconut oil ;-)

Tuesday, March 15, 2011

Energy Drinks Increase Resting Metabolic Rate, But Do Not Influence Energy Expenditure During Exercise

Ever wondered, whether the drink that was once rumored to contain "taurine from bull sperm" and similar fashionable "energy drinks" are of any use? Well, a recent study (Nienhuesser. 2011) coming from an international team of scientists showed that the consumption of each and every of the three energy drinks used in this study lead to a statistically significant increase in resting metabolic rate (RMR).
[...] in a randomly assigned cross-over design, the subjects consumed 473 ml of one of three commercially available energy drinks or a placebo and then RMR and RER [respiratory exchange ratio; i.e. a measure of the relative amount of fat/carbs that is used as fuel] were measured 1 hour later.  The subjects then engaged in 15 minutes of treadmill exercise at 50% of V02max, during which RER and oxygen consumption (VO2) were measured. RMR was not changed by placebo, but increased (P<0.05, means ± se) above baseline by 10 ± 2.5%, 15.0 ± 2.9%, and 15.3 ± 2.9%, following Energy Drink One, Energy Drink Two, and Energy Drink Three (respectively) [...]
In view of the stimulating effect, some of the ingredients (cf. Table 1) of these chemical containing beverages exhibit, these results do not come as a surprise.
Table 1: Listing of ingredients according to Nienhuesser. 2011
What may be surprising, however, is that the study results suggest that - at least from a "calorie expenditure" point of view - the consumption of an energy drink before exercise appears to be less effective than drinking it after exercise or at your desk at the office...

Saturday, March 12, 2011

Carbohydrate Restriction Reduces Liver Triglycerides More Effectively Than Calorie Restriction - With Equal Weight Loss Outcomes.

A calorie is not a calorie, I hope you knew that even before Garry Taubes published his famous NY Times best-seller. Yet, in case you are still looking for respective studies to show to medially indoctrinated family members or friends, who still believe that - even if fat is not the enemy - half ratios would be the key to health & longevity, you might be interested in the results of a very recent investigation by Browning et al. (Browning. 2011).

The scientists put a group 18 non-alcoholic-fatty-liver patients on either a carbohydrate-restricted (<20g/day) or a calorie restricted (1200-1500kcal/day) diet - just to make sure you get this right: the carb-restricted group ate as much calories as they wanted! - and measured hepatic triglyceride levels before and after the 2 week dietary intervention. Probably to the surprise of many members of the medical orthodoxy, both groups lost about the same amount of weight (in fact the low-carb group lost -4.6kg, while the low-calorie group lost only -4.0kg!), yet the low-carb group had a much greater reduction in hepatic triglyceride levels:
Liver triglycerides decreased significantly with weight loss (P , 0.001) but decreased significantly more (P = 0.008) in carbohydrate-restricted subjects (-55.6%) than in calorie-restricted subjects (-28.6%).
So, even if you are not particularly interested in your liver health, the fact that by eating to satiety and just dropping your carb intake to <20g/day you can lose the same ~4.5kg you would lose if you starved yourself for 14 days should prick your ears.

Wednesday, February 23, 2011

High MUFA Diets are (Heart-)Healthy and Probably Superior to High PUFA Diets

Ever since the "Mediterranean Diet" was/is the talk of the town, more and more people become aware of the potential benefits of the formerly largely ignored mono-unsaturated fatty acids (MUFAs). In spite of that, the majority of consumers (probably due to the misinformation coming from the marketing machinery of the food industry) still focuses on avoiding the "bad" saturated fats and consuming as much "healthy" polyunsaturated fats (PUFAs) as possible in order not to fall victim to an obesity epidemic which is inseparably intertwined with these kind of black-and-white approaches to nutrition.

In an extensive review (Jones. 2011) scientists from the Department of Human Nutritional Sciences at the Richardson Centre for Functional Foods and Nutraceuticals (University of Manitoba, Canada) evaluated data from over 50 years of research to come to the conclusion:
Consumption of dietary MUFA promotes healthy blood lipid profiles, mediates blood pressure, improves insulin sensitivity and regulates glucose levels. Moreover, provocative newer data suggest a role for preferential oxidation and metabolism of dietary MUFA, influencing body composition and ameliorating the risk of obesity. Mounting epidemiological and human clinical trial data continue to demonstrate the cardioprotective activity of the MUFA content of dietary fat.
In fact, they found MUFA rich diets to be superior even to diets enriched in PUFAs, which have lately oftentimes been hailed as the saviors of the fat and unhealthy:
When PUFA and MUFA rich diets were compared for replacement of dietary SFA in healthy adult subjects, those consuming MUFA rich diets demonstrated a preservation of HDL-C levels to a greater extent with only a 4% decrease in HDL-C levels compared to those consuming PUFA rich diets, which decreased HDL-C levels by 14%.
What is interesting, however, is that there still seems to be an initial bias against saturated fatty acids. This can also be seen from the fact that the general questions the authors pose throughout their review always come back to the idea of replacing saturated fatty acids by either carbs or MUFA, PUFA or MUFA etc. I would be interested to see a study or a review without this initial bias against saturated fats - the results could be very interesting... what do you think?

Sunday, February 20, 2011

Want to Stay Lean on a High-Fat Diet? Consume Whey Protein Everyday.

Listeners of Carl Lenore's Super Human Radio already know: Dr. Paul Arciero of Skidmore College is going to publish a study the results of which confirm that obese individuals can lose weight and improve markers of metabolic health by just adding a 20g shake of whey protein 3x a day.

While you still have to wait for the detailed results of this study to be published, another group of scientists (Shertzer. 2011) derived similar results from a study on mice. Despite being on a high fat diet, mice who received 100mg of whey protein isolate (WPI) per liter of their drinking water (WPI group) ...
had lower rates of body weight gain and percent body fat and greater lean body mass, although energy consumption was unchanged. These results were consistent with WPI mice having higher basal metabolic rates, respiratory quotients, and hepatic mitochondrial respiration. [...] Livers from WPI mice had significantly fewer hepatic lipid droplet numbers and less deposition of nonpolar lipids. Furthermore, WPI improved glucose tolerance and insulin sensitivity.
While you are waiting for the human study to be published (the SuppVersity will have it first ;-), get yourself some tasty whey protein and listen to Dr Arciero on Super Human Radio!

Thursday, February 17, 2011

Burn Additional 27 kcal with 6mg/kg Caffeine Pre-Workout

Caffeine is the cornerstone of almost each and every fat-burner on the market. But how effective is it in raising your energy expenditure? A study (Astorino. 2011) conducted at the Department of Kinesiology of the California State University provides an answer: Not very effective.

Astorino et al. had 14 strength-trained men who were regular caffeine consumers perform a strength workout with either 6mg/kg (thanks to Ezhan who pointed me to a type here. It's 6mg not 0.6 as it said before) caffeine or placebo supplement pre-workout. What they found was that
Caffeine intake increased total energy expenditure by 15% (P<0.05), but the additional calories burned was minimal (+27 kcal).
Well, I suppose this is about the amount of calories of a small carrot and not really what you would expect from a fat burner.

Wednesday, February 16, 2011

Lose More than 2 Pounds of Fat-Mass in Less than 30 Minutes: The Illusiveness of Bioelectrical Impedance Analysis

Wouldn't it be nice to burn more than 2 pounds of body-fat within 30 minutes of exercise? Well, according to your body impedance scale this is easily possible! You would even gain 1 pound of solid muscle...

In a recent study Selma Civar Yavuz (Yavuz. 2011) had 52 healthy volunteers perform an exhaustive treadmill exercise (Bruce test) and evaluated the body composition changes by the means of bioelectrical impedance analysis. The results summarized in Table 1 are amazing:
Table 1: Comparison of the body mass index (BMI), fat mass (FTM), fat free mass (FFM), total body water (TBW) and bioelectrical impedance measurements taken before and after the exercises.
What is amazing about these results is yet not the amount of fat the subjects burned in <30 min of running. Its rather the inaccuracy of the impedance analysis. In view of the results of this study you better throw your expensive body-fat scale out of the window and revert to using an old fashioned tape measure to evaluate your dieting / exercise success.

Sunday, February 13, 2011

Glycogen-Depleted Athletes may Benefit from 0.3g/kg BCAA Supplementation: Improved Endurance & Lipid Oxidation

If you have ever read up on the general recommendations concerning "cardio on an empty stomach" you will most likely have encountered the advice to supplement with branched-chained amino acids (BCAA) before or in the course of the workout. I have always considered this to be a solid advice, up to now, I had yet not seen a study underpinning the common sense reasoning behind the suggestion.

Now, Gualano et al. (Gualano. 2011) published a study that investigated the effect of BCAA supplementation on exercise performance and energy metabolism in glycogen-depleted athletes (let's assume by now that an athlete following a low carb diet is in fact glycogen-depleted when he wakes up). In a double-blind placebo controlled fashion the scientists provided their subjects with either 0.3g/kg BCAA or placebo for 3 days...
On the second day, subjects were submitted to an exercise-induced glycogen depletion protocol. They then performed an exhaustive exercise test on the third day, after which time to exhaustion, respiratory exchange ratio (RER), plasma glucose, free fatty acids (FFA), blood ketones and lactate were determined. BCAA supplementation promoted a greater resistance to fatigue when compared to the placebo (+17.2%). Moreover, subjects supplemented with BCAA showed reduced RER and higher plasma glucose levels during the exhaustive exercise test.
For all of you who are now asking themselves, what validates the claim of increased fatty acid oxidation, its the reduced respiratory exchange ratio. Although its arguable how reliable a measure the ratio between O2 in and CO2 out is in terms of fatty acid metabolism, these results support the hypothesis and real world observation that BCAA-supplemented cardio on an empty stomach reliably promotes fat loss.

Sunday, January 30, 2011

Resveratrol Increases Lipolysis and Reduces Lipogenesis in Mature Adipocytes

If you are (as I hope) an avid reader and daily visitor of the SuppVersity, you probably remember Friday's news on the "Side Effects of Polyphenol Supplementation". I just hope you did not throw away all your supplements immediately, because eventually the question of side effects is always relative. If, for example, you are a sumo competitor and in dire need of gaining mass, no matter what. It would be an unwelcome side-effect of resveratrol supplementation not to gain or even to lose body fat...

A report (Baile. 2011), recently published in the Annals of the New York Academy of Sciences does now confirm, what supplement companies have been promising all along: the right dose of supplemental resveratrol will limit fat gain and improve lipolysis in a mouse model:
Treatment of mice with resveratrol alone was shown to improve resistance to weight gain caused by a high-fat diet. Moreover, dietary supplementation of aged ovariectomized rats with a combination of resveratrol and vitamin D, quercetin, and genistein not only decreased weight gain but also inhibited bone loss.
The human equivalent dose to that used in the cited study would be about 35mg/kg (= 2.800mg for a 80kg human being), which, unfortunately, is much more than your average resveratrol product contains. So, what does this tell you? Either you spend a fortune for minor improvements in your resistance to an unhealthy diet OR you just consume a healthy diet in the first place - I bet you will end up leaner and healthier using the second option.

Saturday, January 15, 2011

Calcium + Vitamin D for Breakfast Increase Dietarily Induced Thermogenesis and Fatty Acid Oxidation

Ever since the first studies suggested beneficial effects of dairy on weight loss, there have been a lot of trials that investigated the role of (supplemental) calcium in these contexts (mostly with discouraging results). A very recent study by Wendy and Soares (Wendy. 2011) took a very similar approach, but added vitamin D to the equation.

In their study, the scientists fed their 11 subjects (aged (mean ± SEM) 54 ± 1.2 y and BMI 31 ± 2.4 kg/m) a meal that was either high (HCT) or low (LCT) in vitamin D and calcium and measured diet induced thermogenesis (DIT), fat oxidation rates (FOR), serum leptin, subjective feelings of hunger/satiety hourly over a period of 8 hours. The results were far from earth-shattering; they could however solve the mystery of why most people find it easier to lose weight on a diet that is generally rich in dairy and calcium + vitamin D rich foods:
HCT resulted in lesser suppression of ΔFOR (p=0.02) and a significantly greater DIT (p=0.01). Further, the buffet to dinner interval was prolonged (p=0. 083) and reported 24h energy intake following this trial was significantly reduced (p=0.017). ∆leptin following HCT but not LCT was negatively related to 24 h fat intake (r = - 0.81, p=0.016).
So, the underlying mechanism is actually threefold and much different from the commonly heard hypothesis that dietary caclium would "bind fat in the intestine" and thus reduce caloric intake:
  1. greater postprandial fat oxidation
  2. significantly greater thermogenesis
  3. beneficial effect on leptin and thus decrease in hunger
What else would you want? If there was not the issue with lactose intolerance, eating as much dairy as possible could actually become a general recommendation for everyone who intends to lose weight and/or improve body composition

Friday, January 14, 2011

6 Weeks of 400mcg Chromium per Day Improve Insulin Sensitivity and Lean Body Mass in Obese Children over Lifestyle Intervention Alone

Chromium, once hyped as a next generation anti-diabetes and lean mass agent, has disappeared from the best-selling lists of supplement vendors. Too few studies were able to confirm the encouraging results from rodent experiments. Possible toxicity issues put the icing on the cake and people just stopped buying it.

A very recent study published in the Journal of Nutritional Biochemistry (Kim .2010) took another look at whether chromium, which irrefutably is a vital co-factor in insulin production and secretion, may not yet be beneficial for patients with pre-diabetes. The scientists supplemented a group of 25 obese children (age 9-12y) who participated in a 6-week diet and lifestyle intervention with 400mcg chromium chlorid a day and monitored changes in body mass index (BMI; kg/m2), BMI Z-score, waist circumference, body composition and fasting plasma glucose. The results were positive- body composition and insulin sensitivity improved:
[...] children who received chromium chloride demonstrated more positive changes versus the placebo group in HOMA (−1.84±1.07 vs. 0.05±0.42, P=.05), QUICKI (0.02±0.01 vs. −0.002±0.01, P=.05), lean body mass (2.43±0.68kg vs. 1.36±1.61kg, P=.02) and percentage body fat (−3.32±1.29% vs. 0.65±1.05%, P=.04)
Once again, chromium did not prove to be the panacea of the age of obesity, but supplemental chromium can be a beneficial co-factor in the treatment of metabolic disorders in general and diabetic complications in particular. Without appropriate life-style interventions it will however prove similarly useless as many other supplements which have been "proven in clinical studies to do XYZ"...

Sunday, January 9, 2011

Tired of Being Obese? Walk Like a Bodybuilder! Study Confirms Effectivity of Incline Treadmill-Walking

Are you obese or just generally concerned about your joint health? Forget jogging and ramp up your treadmill. According to the results of a study published in the latest issue of the Journal of the American College of Sports Medicine (MSSE. 2011) slow walking on an incline produces a similar metabolic workload as running while concomitantly reducing loading rates on lower extremities:
Metabolic rates were similar across trials and were moderate intensity (48.5-59.8% of VO2max). Walking slower uphill significantly reduced loading rates and lower extremity net muscle moments compared to faster level walking. Peak knee extension and adduction moments were reduced by ~ 19% and 26%, respectively, when subjects walked up a 6[degrees] incline at 0.75m/s vs. level walking at 1.50m/s.
So, ramp up your incline and walk, but please do me a favor and do not hold on to the handle in front of you, like some of the overweight mamas at my gym do. This will not only reduce the work-intensity and thus diminish the metabolic effect, it may as well ruin your back.

Edit: Dr. Rouse was kind enough to remind me that there is a world beyond the gym (cf. my Facebook page) and that just walking outside would be a better alternative - thanks Peter ;-)

Saturday, January 8, 2011

L-Carnitine Works! At Least if it's L-Carnitine L-Tartrate.

Initially, carnitine was considered the super-supplement for both, the athlete seeking the ergogenic edge, as well as for the obese trying to shed unhealthy body fat. Surprisingly, however, study after study showed no to little effect on exercise performance and/or fat loss. Ultimately, it became clear that, even at very high doses, only very little of the orally delivered l-carnitine actually makes it to the muscle. Consequently, its effects on performance and body composition where negligible. Now, a very recent study by Wall et. al. (Wall. 2011) found that adding a transporter, in this case l-tartrate, to the molecule does not only help to increase muscle carnitine levels, it eventually produces exactly those effects on exercise performance and substrate metabolism one would have expected from l-carnitine supplementation in the first place.

The scientists had their 14 healthy male volunteers ingest either 80 g of CHO (Control) or 2 g of L-carnitine L-tartrate and 80 g of CHO (Carnitine) twice daily for 24 weeks in a randomised, double blind manner. Other than in previous studies with plain l-carnitine (minus the l-tartrate) there was a significant increase of muscle carnitine content with all the downstream metabolic benefits on exercise performance one would expect:
Muscle TC increased from basal by 21% in Carnitine (P<0.05), and was unchanged in Control. At 50% VO2max, the Carnitine group utilised 55% less muscle glycogen compared to Control (P<0.05) and 31% less pyruvate dehydrogenase complex activation (PDCa) compared to before supplementation (P<0.05). Conversely, at 80% VO2max, muscle PDCa was 38% higher (P<0.05), acetylcarnitine content showed a trend to be 16% greater (P<0.10), muscle lactate content was 44% lower (P<0.05) and the muscle PCr/ATP ratio was better maintained (P<0.05) in Carnitine compared to Control. The Carnitine group increased work output 11% from baseline in the performance trial, while Control showed no change.
So, after all, it was not the wrong the substance previous investigations used, but rather the wrong form - l-carnitine l-tartrate - though expensive - is the way to go to burn fat and increase athletic performance. If you do not want to buy it in bulk, I suggest you at least buy a product like MAN Sports Body Octane, where you actually know how much (here 1g) of the carnitine you're getting per serving.

Sunday, January 2, 2011

Even Individuals on a "Healthy" Diet May Benefit from Supplemental Fiber

Fiber has been advertised for years as a universal health promoter. It curves appetite, reduces cholesterol and improves digestion - but is it really necessary to supplement with additional fiber, if your intake in fibrous veggies etc. is already high? A recent study by scientists from Australia (Pal. 2010) suggests that it may not be necessary, yet beneficial.
Figure 1: Changes in body weight (A); BMI (B); % body fat (C) and waist circumference (D).
From left to right: Control, FIB, HLT, HLT-FIB

Studying a cohort of 72 overweight and obese individuals with a BMI between 25 and 40 kg/m2 and age between 18 and 65 years, the researchers found that over a time period of 12 weeks in which the subjects either practiced their "normal" eating habits or changed to a healthy food diet (HFT), supplemented with fiber (FIB) or switched to a healthy food diet that was supplemented with fiber (HFT-FIB)...
[...] weight, BMI and % total body fat were significantly reduced in FIB and HLT–FIB groups, with weight and BMI significantly reduced in the HLT group compared with control at 12 weeks. HLT–FIB and HLT groups had significant reductions in TAG and insulin compared with control at 6 and 12 weeks, and in insulin compared with the FIB group at 12 weeks. The HLT–FIB, HLT and FIB groups all had significant reductions in total cholesterol and LDL-cholesterol compared with control after 6 and 12 weeks.
As can be seen from figure 1 (above) the addition of fiber to an already healthy diet did in fact improve the overall beneficial results of the change in dietary habits. Bottom line: Firstly, eat healthy! Secondly, consider using a fiber supplement only if your diet is already in check.

Friday, December 31, 2010

Fish, but not Fish Oil Supplements Reduce Breast Cancer & All-Cause Mortality Risk in Women

This is another piece of information which came up in the course of my recent research into the latest studies on fish oil supplementation: Capped fish oil, obviously, is very different from the "real deal" fish... you know that stuff that is swimming in the ocean and does not come in convenient 1 gram caps; that stuff that stinks like fish and is not molecularly distilled or filtered, ...

Researchers from the University of California (Petterson. 2010) recently found that...
Women with higher intakes of EPA and DHA from food had an approximate 25% reduced risk of additional breast cancer events [tertile 2: HR = 0.74 (95% CI = 0.58-0.94); tertile 3: HR = 0.72 (95% CI = 0.57-0.90)] compared with the lowest tertile of intake. Women with higher intakes of EPA and DHA from food had a dose-dependent reduced risk of all-cause mortality [tertile 2: HR = 0.75 (95% CI = 0.55-1.04); tertile 3: HR = 0.59 (95% CI = 0.43-0.82)]. EPA and DHA intake from fish oil supplements was not associated with breast cancer outcomes. The investigation indicates that marine fatty acids from food are associated with reduced risk of additional breast cancer events and all-cause mortality.
Of course, this again is one of those epidemiological studies, I, myself tend to criticize from time to time. Nevertheless, I find it very intriguing that, whenever we switch from natural to artificial versions of foodstuff, good things lose their value - or even become detrimental for your health.

Wednesday, December 29, 2010

Exercise at the Anaerobic Threshold Increases GH Release and Burns Fat in Obese Patients with Type 2 Diabetes

Scientists still argue about the most important contributing factor to the ever increasing obesity epidemic in the Western World: Is it bad dietary habits or our sedentary lifestyle - honestly, I don't care... you got to work on both if you want to stay healthy.

The results of a recent study published by scientists from the Toho University Sakura Medical Center (Yamaguchi. 2010) do yet underline the importance of exercise (and I mean exercise, as in sweating and panting, not just walking to your car!) in the "health equation", i.e. "diet + exercise = health". The scientists had their 19 obese type 2 diabetics either keep their sedentary lifestyle or performed 2× 30-min bouts of exercise (treadmill walking) everyday in the morning and evening during the 4-week study period. What is of particular importance is that the exercise intensity was determined by pretesting the exercise capacity of each participant, so that all patients exercised at their individual anaerobic threshold. The results of this regimen (cf. table 1) were quite remarkable:
Table 1: Baseline characteristics and changes in clinical and biochemical variables.BMI: body mass index, VFA: visceral fat area, SFA: subcutaneous fat area, BP: blood pressure, FPG: fasting plasma glucose, HbA1C: hemoglobin A1C, HOMA-IR: homeostasis model assessment of insulin resistance, TC: total cholesterol, TG: triglyceride, HDL-C: HDL-cholesterol, LDL-C: LDL-cholesterol, IGF-1: insulin-like growth factor-1, LPL mass: LPL mass in preheparin serum.
In view of recent research findings about the relation of visceral fat (VFA) and metabolic derangements, the remarkable reduction of VFA by -21.7% vs. -5.5% in the control group is of paramount importance for the subjects' health. The researchers attribute this success mainly increases in growth hormone which were elicited by the exercise intervention. In that, it is important to note that we are talking about a 100% increase in growth hormone after a 30-min bout of exercise.

Although this is just speculation on my part, I think it is questionable whether walking for more than 30 minutes, but at a lower intensity would have provided similar results. Or in other words: If the key is to trigger metabolic changes (via natural hormonal pathways) intensity (not overexerting oneself, though) is key.