High CGA Instant Coffee for High Potency Fat Loss: Visceral and Total Fat Loss Increase 6-9-fold 😮, But...

Truth is in the numbers... the absolute numbers, not the impressive relative visceral fat loss that doesn't show on either scale, measuring tape, or mirror... and yes, that means that Kao's high-octane CGA enhanced coffee is not going to make you lean out effortless- and visibly in 12 weeks in the absence of making the necessary but (by way too many) dreaded dietary / lifestyle changes.

"No", it's not #inMice, but "yes", it's sponsored research by the Kao Corporation about whose "High Octane Coffee" I've written last year, already. In their latest paper the Japanese authors of the paper (Watanabe 2019) investigated the effects of daily consumption of coffee enriched in chlorogenic acids (CGA) on abdominal fat area in a 12-wk randomized, double-blind, parallel controlled trial w/ healthy, overweight men and women (n = 150, body mass index (BMI) ≥25 to <30 kg/m²) who were randomly allocated to high-CGA (369 mg CGA/serving) or control (35 mg CGA/serving) coffee groups.

You can learn more about coffee and caffeine at the SuppVersity

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Quantifying the Benefits of Caffeine on Ex.

The subjects were recruited from among men and women (it's a bit suspicious that the authors don't report the sex-ratio in the FT, though) residing in the Hokkaido area in Japan.

• 

  Must read: "Buying, Roasting, Grinding, Brewing: Coffee 101 -- How to Do it to Get the Optimal Stimulant and/or Health Effects" | read the SuppVersity Classic

  The inclusion criteria were as follows: body mass index #BMI ≥ 25 to <30 kg/m² (=obesity class 1; often just labeled as 'overweight'); visceral fat area #VFA ≥ 80 cm² (rather high levels of pro-inflammatory organ fat); age 20 to <65 years. 
• The exclusion criteria were as follows: allergy to drugs or food; current disease or history of severe disease related to the liver, kidney, heart, lungs, or digestive system; systolic blood pressure <90 mmHg or ≥160 mmHg; heavy drinking (>30 g alcohol/day) or smoking; extremely irregular dietary habits; and shift work or late-night work. 

The scientists also (pre-)calculated the sample size based on data from the previously discussed paper assessing the effects of CGA-containing pre-packed coffee beverages on overweight subjects:

"The number of subjects (71 subjects/group) was calculated on the basis of the assumption of a change in VFA (ΔVFA) of 5 cm², standard deviation of 15 cm², significance level of α = 0.05, and power (1 − β) = 0.80. To account for the potential for dropouts, the target number of subjects was set at 150" (Watanabe 2019). 

Moreover, the trial was registered at www.umin.ac.jp/ctr/ as UMIN000036011. Now, none of these parameters guarantee that the study is unbiased, objective, practically relevant, etc. but trial registration, power calculations, inclusion of only "healthy" overweight subjects, a study duration of 12 weeks, dietary control that shows a lack of differences between the two study groups (see Table 1) are indicators of study quality and real-world relevance of a study you will certainly see being referred to in adds for the instant coffee I previously labeled as "high octane coffee".

Composition and nutritional content of test coffee. CGA—chlorogenic acid (from Watanabe 2019); note the difference in energy content (and carbs 😯 that would suggest weight loss advantages for the control coffee)

What's in the high octane coffee? From the Coffee 101 on SuppVersity.com you know that you can control the CGA content of your coffee by buying, roasting, grinding, and brewing your coffee 'the right way'. Even with your "greenest" roast and minimal processing, though, you're unlikely to squeeze out >300mg of chlorogenic acid #CGA as a "minimum guaranteed amount per serving" while simultaneously decreasing the oxidant components through a previously described and tested adsorptive treatment with activated carbon (Ochiai 2009; Kajikawa 2019 | both studies show benefits for CV health).

In general, the coffee doesn't differ much from your average instant coffee which is likewise prepared after spray-drying but contains less than 1/10th of the amount of CGA in Kao's 'high octane coffee' - it's thus quite credible that the scientists claim that their CGA coffee with 369 mg of CGA/serving and the 35 mg of CGA/serving control coffee were "indistinguishable".

Only a single serving did the trick! All instant coffee was consumed (only) once daily for 12 weeks, with four-week pre- and post-observation periods. Abdominal fat area and anthropometric measurements were analyzed at baseline and at four, eight, and 12 weeks, and 142 subjects completed the study - that's pretty much in line with what the power-analysis suggested to be necessary.

Table 1: Dietary intake at 0 and 12 weeks in control and CGA groups. Data are presented as mean ± SD. Control (n = 70), CGA (n = 72). Group represents p-value in effect of group. Time represents p-value in effect of time. Group × time represents p-value in effect of group × time interaction - all analyses by repeated-measures ANOVA (Watanabe 2019).

In conjunction with the absence of dietary changes illustrated in Table 1 (obviously the study wasn't as controlled as a metabolic ward study), the weight ... ah, I should say fat loss effects of the elevated CGA intake was quite impressive: The absolute values and changes from baseline in visceral (#VFA), subcutaneous (#SFA), and total (#TFA) fat area are shown in Table 2.
(Watanabe 2019)

Table 2: Changes in physical assessment parameters in control and CGA groups (

As the authors point out, "[t]he CGA group exhibited a significant decrease relative to the control group at 12 weeks by t-test in VFA (CGA group: −9.0 cm², control group: −1.0 cm², p = 0.025) and changes in VFA from baseline, i.e., ΔVFA (p < 0.001)" (Watanabe 2019). In plain English:

Even in the absence of a meaningful conscious (or at least detectable) reduction in energy intake, a single cup of the high octane coffee shed 9.0 cm² visceral, i.e. metabolically particularly unhealthy fat - that's 9x more than the obviously non-significant -1.0 cm² the subjects in the control group dropped on their 12-week journey.

Is there such a thing as an optimal caffeine:taurine ratio? Plus MORE!

How high should/can you probably go? You will remember the 25 cups a day study discussed in the SuppVersity News in early June. With those 25 cups you'd get 2-3 times the amount of CGA in the Kao Coffee - without, and that's what the coverage of the pertinent study by Fung et al. (2019) seems to suggest increasing your risk of heart disease... Bad news for coffee junkies, though, the statistical analysis compared self-reported coffee consumption habits between only three groups, ie ≤1, 1–3, >3 cups/day - with the lowest group used as the reference in the analyses, the actual study doesn't tell us anything about the health effects of drinking 25 cups of coffee per day (plus: subjects who consumed even mere were excluded from the analysis).

In contrast to what the FT of the study seems to suggest (there it says: "[t]he change in the TFA from baseline (ΔTFA) was significantly smaller [sic!] in the CGA group compared with the control group at 12 weeks" | Watanabe 2019), the significant group × time interaction (p = 0.001) and the group effect (p < 0.001) the scientists observed for the total body fat area (see Table 2 #TFA) clearly favored the CGA coffee of which I am not even sure that it's already on the market, as well.

Figure 1: My plot of the absolute visceral (#VFA) and subcutaneous (#SFA) development in Watanabe 2019 shows: inter-group comparisons as I present them in the headline and relative changes as presented in the arrow an easily mislead you to overestimate the practical (in mirror) significance of the results.

Against that background, it doesn't come as a surprise that the CGA subjects also lost more body weight, BMI, and inches off their waists (#BW, #BMI, #WC | p = 0.025, p = 0.015, p = 0.001, respectively); a result the authors provide some additional substance to, when they write...

"[...] Δweight, ΔBMI, and ΔWC in the CGA group had a significant group × time interaction compared with the control group by repeated-measures ANOVA (p = 0.010, p = 0.006, and p = 0.012, respectively). Moreover, a significant group effect was detected for ΔWC (p = 0.023); i.e., WC in the CGA group was significantly decreased (0.8 cm) relative to that in the control group at 12 weeks (p = 0.001, t-test). With respect to Δweight and ΔBMI, the CGA group showed a decreasing trend relative to the control group (p = 0.080 and p = 0.071, respectively)" (Watanabe 2019).

What may be surprising and certainly not irrelevant for the discussion of the results in terms of the number of holes the subjects had to tighten their belts. With an average reduction in waist circumference of only 0.7 cm = 0.28 inches, they went from a somewhat tight, to a marginally more comfortable fit in their 36" jeans, which should remind you of the "but" in the headline.

While the comparison to the control group in the study at hand suggests an added benefit of extra-CGA, observational studies show that merely drinking enough coffee is associated with less total and visceral body fat with statistically significant dose-effect trends; values in cm² difference vs non-coffee drinkers (Mure 2013).

Don't expect miracles, the results were relatively (%) huge... absolutely (cm²) tiny and practically (mirror) invisible. W/ a 'weight loss' of 200g and effectively no reduction in the circumference of their bellies, most of the subjects in the study at hand would probably argue that the high octane coffee from the Kao Corporation was as useless as the CGA supplements Dr. Oz promoted in his show; and let's be honest: Who wants to blame them, in the absence of reductions in unaesthetic subcutaneous fat and virtually identical readings on the scale and the measuring tape!? No one. And no one should, either, 'cause the actual take-home message of the study reads: CGA seems to improve the body fat distribution of healthy overweight-to-slightly-obese subjects in a large(r) scale randomized controlled 12-week study without showing on the scale, in the mirror or your waist.

I guess, now it's up to you decide if you will be willing to pay the CGA premium for Kao's 'high octane' instant coffee (when it's available wherever you may live), or if you simply go back to the #1 article about preparing coffee on the Internet (that's obviously my "Buying, Roasting, Grinding, Brewing 101") to remind yourselves that cold-brewing, choosing Robusta over the more-expensive and valued Arabica beans and consuming a dark(er) vs. medium roast may help you increase the CGA content of your morning, mid- + late-morning, lunch, and PM coffee(s) signif. while providing you with a good rationale to justify consuming way more than one pot of the pro-metabolic, anti-diabetic organ-fat burning brew of the Gods (Marventano 2016; Mure 2013) | Comment!

References:

• Fung, Kenneth, et al. "9 Effect of coffee consumption on arterial stiffness from UK biobank imaging study." (2019): A8-A10.
• Marventano, Stefano, et al. "Coffee and tea consumption in relation with non-alcoholic fatty liver and metabolic syndrome: A systematic review and meta-analysis of observational studies." Clinical nutrition 35.6 (2016): 1269-1281.
• Mure, Kanae, et al. "Habitual coffee consumption inversely associated with metabolic syndrome-related biomarkers involving adiponectin." Nutrition 29.7-8 (2013): 982-987.
• Kajikawa, Masato, et al. "Coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone improves postprandial endothelial dysfunction in patients with borderline and stage 1 hypertension." European journal of nutrition 58.3 (2019): 989-996.
• Ochiai, Ryuji, et al. "Effects of hydroxyhydroquinone-reduced coffee on vasoreactivity and blood pressure." Hypertension Research 32.11 (2009): 969.

Intermittent Fasting in Trained Women Adds Same Amount of Muscle, Strips Extra Body Fat (4-6%) | No Effect of HMB

HMB did matter, but not significantly; and fasted training was not involved in the extra-fat loss and improvement in body composition.

While it has long been discussed if serious gainz are even possible on time-restricted feeding regimen, such as classic 'intermittent fasting', SuppVersity readers have known for years that "New 'Lean Gains' Study Confirms: IF Gets Athletes Lean & Improves Insulin Sensitivity W/Out Impairing Their Gains" (➡article discussing Moro 2016) - that's in men, though, and that, in turn, is one of several factors that make the latest study by Tinsley et al. (2019) worth looking at.

In their latest study, the Texas Tech University researchers combined two research questions into one study: (a) Does time-restricted feeding affect the adaptive response to resistance training women? (b) Can this effect be augmented and/or modulated by supplementing the leucine-metabolite HMB during the fasting phases (and once in the PM)?

Learn more about fasting at the SuppVersity

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You're wondering why on earth someone would still do research on HMB? Well, the study was supported by MTI Biotech Inc. who sell HMB and there's nothing reprehensible about financial support from the supplement industry... as long as it does not lead to irreproducible (and, for many, hardly credible) results as it may have been the case of the notorious free-form HMB study by Wilson et al. The reason we should still keep the role of the sponsor of which the scientists write that neither this nor the other supporter, Dyamatize, "play[ed] a role in the overall design or execution of the study, the analysis, and interpretation of the data, or the presentation of the results found in this article" is that sponsorship can lead to an often unconscious reporting bias and/or a certain emphasis on pro-supplement conclusions in the discussion of the results.

But we will get to potential issues with the presentation and interpretation of the results later. Let's first take a look at the study design as it is described in the abstract:

"This study employed a randomized, placebo-controlled, reduced factorial design and was double-blind with respect to supplementation in TRF groups. Resistance-trained females were randomly assigned to a control diet (CD), TRF, or TRF plus 3 g/d HMB (TRFHMB).

Figure 1: Study timeline and assessments. RT, resistance training (Tinsley 2019).

TRF groups consumed all calories between 1200 h and 2000 h, whereas the CD group ate regularly from breakfast until the end of the day. All groups completed 8 wk of supervised RT and consumed supplemental whey protein. Body composition, muscular performance, dietary intake, physical activity, and physiological variables were assessed. Data were analyzed prior to unblinding using mixed models and both intention-to-treat (ITT) and per protocol (PP) frameworks" (Tinsley 2019).

A closer look at what exactly the 18 and 30 y-old women with significant training experience (≥1 y of RT at a frequency of 2 to 4 sessions per week w/ weekly training of major upper- and lower-body muscle groups), who were recruited via posters, e-mail announcements, and word of mouth, did in this prospectively registered (clinicaltrials.gov) experiment.

Starting to Have Breakfast is Worst New Year's Resolution ... Unless You Want to Gain Weight more

Habituation effects were addressed: From my article about the habituation effect of breakfast eating on the metabolic effects of breakfast skipping and the ill effects of changing this habit, you will remember that it can be an issue if you put subjects who are used/not used to eating first thing in the morning on a time-restricted feeding regimen. Against that background it's of particular importance that Tinsley et al. (2019) stratified participant based on not just on BF% at screening (15–21% or >21%) but also based on their habitual breakfast consumption (≥5 d/wk compared with <5 d/wk), before they then randomly assigned the women to one of the three study groups using sequences produced from a random sequence generator.

Also noteworthy: The way fasting and training were timed precludes interference effects of fasted training... I mean, not that we could assume that this would explain the extra fat loss, anyway.

Here's the gist as far as diet, supplementation, and, obviously, the ladies' training regimen are concerned:

• ⏲ the feeding window of the TRF and TRFHMB participants was set to 1200 h - 2000 h each day, while and CD participants were instructed to consume breakfast as soon as possible after waking and to continue to eat at self-selected intervals throughout the remainder of the day;
• 🍕 the only dietary advice the subjects received was to hit their protein intake goals of by consuming whey protein supplement (regular concentrate, nothing fancy 💲 "Elite 100% Whey", Dymatize Enterprises, LLC) on both training and non-training days in order to achieve a protein intake ≥1.4 g/kg/d; 
• 🍣 the target energy intake was prescribed by multiplying resting energy expenditure (REE), assessed via indirect calorimetry, by an activity factor of 1.5 and then subtracting 250 kcal; in that, "[t]he goal of the small caloric reduction was to promote fat loss while still providing adequate nutritional support for muscular hypertrophy"; effectively, the women thus ate more, though that pre-intervention 250, 162, and 90kcal/day for CD, TRF, and TRFHMB, respectively;
• 🍱 the macronutrients averaged out at 28/40/32 for proteins, carbs, and fats - with no inter-group differences and a de-facto protein intake of 1.6g/kg per day in all three groups
• 💊 on top of the whey all subjects consumed, they received either placebo (calcium lactate) or calcium 3x1g HMB supplements; both were identical in appearance and taste, and were matched for calcium (102 mg), phosphorus (26 mg), and potassium (49 mg) content;

• 

  Table 1: Overview of the ladies' workout regimen. Workouts were supervised and took place in the PM (12-18h, with fasting subjects consuming their first meal early if they came in between 12-13h); 25g whey were consumed right after every workout (Tinsley 2019).

  💊x⏲ participants were instructed to ingest 2 capsules on 3 occasions each day: upon waking, midmorning while still fasting, and prior to bed, for a total dose of 3 g/d;
• 💊 the women "were discouraged from consuming any additional sports supplements beyond those provided by study investigators, with the exception of common multivitamin/mineral supplements" (Tinsley 2019).
• 💪 the ladies trained for 8-weeks under supervision and on three non-consecutive days each week (i.e., Mondays, Wednesdays, and Fridays), and 2 different upper- and lower-body sessions were alternated (Table 1); the women trained to momentary failure
• 🍽 the training times were not set in stone, but nobody was allowed to train fasted; hence participants who came in early in the training window from 12-18h, had to break their fast early

In short: The researchers mimicked what a dedicated but not necessarily crazy gymrat could, in fact, be doing for 8 weeks or even longer to improve her physique. Speaking of which, as the scientists report as early as in the abstract, all subjects saw...

Figure 2: Body composition data (per protocol analysis | in the intention to treat analysis, which includes all subjects regardless of adherence, the fat loss advantage was visible but not sign.)

• comparable fat-free mass (FFM) accretion 💪 (+2% to 3% relative to baseline) and skeletal muscle hypertrophy 🤹‍♀️ occurred in all groups, but ...
• statistically different effects on fat mass 🤟 (CD: +2%; TRF: −2% to −4%; TRFHMB: −4% to −7%) were observed in the per-protocol analysis (meaning, when only those who actually adhered to their protocol were included - for all subjects, including those who didn't fast appropriately the effect was no longer significant).

Finally, it's worth mentioning that "[m]uscular performance improved without differences between groups"; and that "[n]o changes in physiological variables occurred in any group, and minimal side effects were reported" (Tinsley 2019).

This study and the latest meta-analysis show: athletes & experienced gymrats don't benefit from HMB supplements.

Did you notice something? Yes, HMB is even mentioned... at least not until the scientists conclude the abstract to their study by somewhat cumbersomely referring to the fact that

"[s]upplemental HMB during fasting periods of TRF did not definitively improve outcomes" (that's my emphasis in a quote from Tinsley 2019).

To me, this seems to be even a tad bit too unbiased; because, as non-significant as the difference may be, the increased fat loss with HMB the scientists observed (cf. Fig.1 FM dark vs. light grey bars) is a recurring theme in HMB research... one of which the previously discussed HMB ↔ body comp. meta-analysis shows that it is yet by no means observed in every study (see Figure 2 | here).

Hence, the take-home is: breakfast skipping works for both sexes and the combination of a small caloric deficit with plenty of high-quality protein will improve your body composition.

So simply stating that "non-significant benefits" have been observed, in the conclusion to the abstract would be perfectly ok, IMHO. The strange "not definitively", on the other hand, could also imply that there some women would indeed benefit and will rather confuse than enlighten the reader without full-text access, whose take away message should be: in the short run and at moderate deficits of only -250kcal/d, time-restricted feeding in the form of breakfast skipping helps women lose extra body fat without measurable effects on lean mass acquisition (let alone loss) when protein intakes are high and high EAA proteins (whey) are provided | Comment!

References:

• Moro, Tatiana, et al. "Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males." Journal of Translational Medicine 14.1 (2016): 290.
• Tinsley, Grant M., et al. "Time-restricted feeding plus resistance training in active females: a randomized trial." The American Journal of Clinical Nutrition (2019).

Stevia: What's New in 2019? Appetite, Food Intake, Fertility, Metabolism, Microbiome | Plus: Is Your Stevia 'Natural'?

Stevia is available in all forms and combinations... often you don't realize before you take a look at the label that it was literally diluted with fillers and other sweeteners such as erythritol etc. Moreover, no one can reliably tell you if the exclusion of the "bitter stuff" and reliance on Rebaudioside A, exclusively, doesn't nullify some of the previously described health benefits of the whole plant.

I was just about to simply add the results of a recent study to your daily dose of research news on "FB/SuppVersity", when it occurred to me that it has been suspiciously quiet on the sweetener front, lately - specifically when it comes to stevia, a sweetener of which many people claim that it was "natural"... But is that true, is what you can buy at the supermarket or online really still "natural"?

While the former is certainly a question of your definition of natural" (do you think a highly processed, isolated white powder is "natural"?).

You can learn more about sweeteners at the SuppVersity

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The Case Against Saccharin: Why it may be different.

Other Diet Soda Additives May be the Real Problem

There's one issue with the (often) Rebaudioside A based products from the shelves, no one can seriously question: Whether the results of studies that are done with the real thing, i.e. stevia leaves of which you could rightfully claim that they are "natural" sweetening agents, will almost certainly not translate 1:1 to the effects of consuming 'stevia' from commercial foods and beverages.

• So why is your "stevia" not the real deal? In view of the results of a recent study in the "Journal of Pharmaceutical and Biomedical Analysis" whose authors (Pacifico 2019) report fifty bioactive constituents in stevia leaves (UHPLC-ESI-QqTOF-MS/MS analysis), you cannot seriously expect that the white powder you call "stevia", which usually is water-extracted and chemical processed Rebaudioside A, the steviol with the least bitterness of all, plus all sorts of fillers and anti-caking agents, will have the same physiological effects on your body as this complex mix of phytochemicals.
  
  

  

  If you want to put that #chlorogenic acid that was lost when your "stevia" was produced back in, study my Coffee 101 it has all the details on how to maximize the CGA content of your home-brewed coffee.

  Speaking of compounds, among the fifty the study identified, non-phenol metabolites, such as benzyl primeveroside and roseoside, as well as a lignan polyphenol (5′), were reported for the first time as constituents of the Stevia leaf. Others, such as chlorogenic acid (the good stuff from coffee) have been detected before but few people are aware of their presence in the true natural sweetener, i.e. the stevia leaves.
  Practically speaking, this means: Your "stevia powder" must not boast any of the health-benefits studies ascribe to either stevia leaves or what scientists would call a 'crude extract'.
  
  This "real deal" forms of stevia have been found to blunt the digestion of carbohydrates, have potent anti-oxidant qualities, and can thus even help alleviate diabetes. With other recent studies showing that the whole leaves (including the bitter compounds) seem to prevent liver disease by modulating hepatic inflammation and fibrosis (Ramos‐Tovar 2018 & 2019), fibrosis and )

Ok, now that you've learned the news that you should have known all along: To call the white stuff from the supermarket a 'natural' sweetener is certainly questionable and unquestionably irrelevant...

Latest review confirms what you've read about sweeteners per se at the SuppVersity - Experimental evidence of ill effects = not convincing: If we widen the scope from Stevia to all non-nutritive sweeteners, it's worth  mentioning Ahmad et al. published in the July issue of "Current Opinion in Clinical Nutrition and Metabolic Care" (Ahmad 2019). The scientists pretty much agree with my previous assessment of the literature when they write that "[o]n the basis of the current evidence, we are still incapable of establishing a definite judgment on whether NNS use truly affects glycaemic control". The authors do however highlight the research on sucralose I analyzed in 2018.

...unless you're stupid enough to believe that everything that marketing people label "natural" is healthy. With that being said, you got to be careful not to (over)generalize the results of a recent review in Current Nutrition Reports which concludes:

"A growing body of evidence indicates that Stevia rebaudiana Bertoni is protective against malignant conversion by inhibition of DNA replication in human cancer cell growth in vitro. Consumption of Stevia has demonstrated to be generally safe in most reports. Further clinical studies are warranted to determine if regular consumption brings sustained benefits for human health" (Rojas 2018)

The same goes for another rave review from last year, in which Samuel et al. praise the promising research on stevia's effects on metabolism, its safety, impact on blood glucose and insulin concentrations, energy intake and weight management, blood pressure, dental caries, naturality and processing, taste and sensory properties (Samuel 2018), and obviously the research results from the last 12 months I've promised in the intro of this article:

• Artificial and sweeteners, obesity, and (in-)fertility revisited - Stevia sticks out: negatively - even compared to aspartame! You may remember from the good old days of short daily SuppVersity articles that there is evidence (from rodent studies) that stevia may impair female fertility... well, a new study (Cho 2018) that investigated the interaction between obesity, low-calorie sweeteners, and prebiotic oligofructose on reproductive parameters - once again in rats, obviously - reports that...
  
  ... stevia, when delivered at 2-3 mg/kg/d in the drinking water, reduces the rate of successful pregnancies by another -7% over the effects of obesity, alone!
  
  In this context, it will come as a relief to overweight human mothers to be who are already pregnant that those 53 percent of the rats who became pregnant had 100% pregnancy and delivery indexes - in other words: the effect must occur before the fertilized egg nests and starts to divide. With only a handful of studies on potential fertility effects of stevia, we are yet far from being able to say with certainty that a high/regular consumption of the "natural" (and, hence, in way too many people's minds "healthy") sweetener poses absolutely no threat to female fertility ... especially if the latter is already endangered by obesity!
• Do sweeteners just make you hungry? No... and for stevia the opposite may be the case! The former is at least what a recent study from the University of Manchester seems to suggest (Stamataki 2019).
  
  For said study, the authors tested in a randomised controlled double-blind crossover trial, how the energy intake of healthy participants (n = 20, 9 males, mean body mass index 21.8 kg/m²) was affected by having different beverages 30 minutes before an ad-libitum (have as much as you want) lunch condition. The test beverages included (C) 330 mL of water (control-no calories and no taste) and either 330 mL of water containing (1) 40 g glucose or (2) sucrose (sweet taste and calories), (3) maltodextrin (calories and no sweet taste), or (4) 240 ppm all-natural sweetener, stevia (Truvia RA-95-sweet taste and no calories).
  
  The additional questionnaires revealed that the stevia and glucose preloads were rated to have equal sweetness levels, while water and maltodextrin the lowest levels of sweetness. As you would expect, though, "only glucose, sucrose and maltodextrin elevated blood glucose" (Stamatki 2019) - interestingly, both the almost non-sweet maltodextrin and the similarly sweet calorie-containing glucose and sucrose, and the stevia treatment significantly suppressed the participants' (all compared to water). What's more important, though is that these observations also translated to the objective (and actually relevant) study outcome: food intake on the ad-libitum meal:

  "Compared to water preload, food intake was significantly lower after the consumption of each of the sweet or caloric preloads" (Stamatki 2019).

  What about stevia? Well, the conclusion of the study says that the study "found a beneficial effect of a stevia beverage consumed prior to a meal on appetite and subsequent energy intake" (Stamatki 2019) - so where's this benefit?
  
  

  

  Figure 1: The figure depicts the cumulative energy intake for all five intervention groups (Stamatki 2019)

  It appears only in the analysis of the subjects cumulative energy intake (preload and lunch), which showed that total energy intake was lower after the stevia preload compared to the water preload.
  
  The latter, i.e. a significant effect compared to water must yet not make us forget that this advantage did not persist when compared to the caloric preloads, which made up for the extra-calories they delivered by suppressing food intake more significantly.
  
  Needless to say, that 24h follow-ups, habituation effects, and - most importantly - studies in people whose natural ability to self-regulate their body weight seems to be impaired - are warranted before advising people to consume a stevia-sweetened beverage before a meal to reduce their overall energy intake... 'cause, after all, we all know that that is what really counts.
• Like everything you eat, stevia will affect your microbiome - the question is: For good or for bad? Further insights into stevia's effects on the microbiome come from University of Calgary (Nettleton 2019), where researchers conducted a rodent study the results of which are worth reporting despite the somewhat uncertain transferability to human beings.
  
  You've read about a putatively negative effect of stevia and "un-"natural sweeteners on the SuppVersity before. You are also well-informed about the under-researched and overhyped role of the gut microbiota as an "important environmental factor that can mediate metabolism and subsequent obesity and disease risk" (Nettleton 2019). To further our insights into what is a much more complex relationship than the NY Times article you may have read (and trusted) suggests, Nettleton et al. didn't just want to confirm and further analyze the stevia-mediated changes in gut microbiota, they also wanted to know if they could be prevented or reserved by the provision of pre-biotics, i.e. food for the allegedly good bacteria. To this ends, they conducted the following experiment:

  "Three-week old male Sprague-Dawley rats were randomized to consume: (1) Water (CTR); (2) Rebaudioside A (STV); (3) prebiotic (PRE); (4) Rebaudioside A + prebiotic (SP) (n = 8/group) for 9 weeks. Rebaudioside was added to drinking water and prebiotic oligofructose-enriched inulin added to control diet (10%). Body weight and feces were collected weekly and food and fluid intake biweekly. Oral glucose and insulin tolerance tests, gut permeability tests, dual X-ray absorptiometry, and tissue harvest were performed at age 12 weeks" (Nettleton 2019).

  With 2-3mg/kg Rebaudioside A, the rodents were fed the human equivalent of approximately 14-15mg which is way below the ADI set by the Health Canada (which is  4 mg/kg bw/day for adults). It is thus not 100% surprising that the study did not reproduce the weight loss effects some previous studies using 30-50-fold higher dosages observed. In a similar vein, the rodents glucose tolerance seemed to be pretty stable - and that's despite the fact that ...

  "[...] the administration of Rebaudioside A did, however, alter gut microbiota composition and reduce nucleus accumbens tyrosine hydroxylase and dopamine transporter mRNA levels compared to CTR" (Nettleton 2019).

  Now, while this may sound pretty bad, it's where the actual news comes in, as the scientists found that the ill effects on the microbiome was attenuated by the provision of prebiotics in the rodents' diet. Moreover, both the prebiotic, alone, as well as the prebiotic + Rebaudioside A group, had reduced fat mass, food intake, gut permeability and cecal SCFA concentration - all four well-known 'side effects' of probiotics.

While the changes in dopamine availability may suggest that the provision of stevia increases the risk of overeating, the rodents intake of the (albeit blatant) diet was unaffected (top); much in contrast to the composition of the microbiome (bottom).

Whut? Stevia reduces dopamine? This is exactly what the Nettleton study shows. If you scrutinize what the scientists analyzed, though, you will realize that their data relates exclusively to the dopamine production and uptake in the mesolimbic reward circuit, where RebA reduced tyrosine hydroxylase (TH | p = 0.044) and dopamine transporter (DAT | p = 0.044) mRNA levels in the nucleus accumbens. In previous studies, similar changes have been linked to food overconsumption - an effect that was, as the figure on the left goes to show you, yet not observed in the study at hand. In view of the fact that the rodents were fed a rather blatant diet the lack of dopamine (~reward) has been linked specifically to the overconsumption of highly palatable food, in particular, any form of definite all-clear signal seems to be unwarranted - especially in view of the fact that these (anti-)dopaminergic effects may well be a downstream effect of the "natural" sweetener on the microbiome (that would also explain its attenuation by prebiotics in the ventral tegmental area,  a group of neurons located close to the midline on the floor of the midbrain).

• What the study adds, though, is that these benefits were not abolished by the coadministration of Rebaudioside A ... well, ok, if you like to poop, you may complain that 'stevia' triggered a significant reduction in cecal weight.
  
  

  

  SIBO-sufferers beware of pre- and probiotics. While they may counter some of the potentially 'bad' effects of stevia, they may mess you up big time | more.

  If you're a stevia junkie it would thus seem prudent to make sure that you get your daily dose of probiotic fiber in your diet ... but wait: if you're already suffering from dysbiosis and or SIBO the 10% FODMAP diet (oligofructose-enriched inulin), the rodents in the study at hand received may actually do more harm than good - as an avid SuppVersity reader you knew that all along, though, right (learn more about SIBO and pro/prebiotics)? If you experience abdominal pain, bloating or the previously discussed brain fog in response to adding inulin rich foods to your diet, you're thus better off with stevia alone.

Suggested read from the SuppVersity Archives: "Can Stevia Help You Ward Off Type II Diabetes? A Review" | Read the full article and/or all posts tagged with stevia from the archives

Stevia, the microbiome and... your teeth! While I suppose that the previous elaborations already gave you more than enough input to think about, there's still one study from early 2019 I would like to mention as it (re-)emphasizes something we tend to overlook over all the hype about the intestinal microbiome: our digestive tract starts in our mouths. In fact, the mouth was the first place where we realized the (in-)direct effects of certain bacteria on our health - the effects of bacteria in the plaque on our teeth on our oral hygiene, the structure of our teeth and, as more recent studies suggest (Noble 2013; Tonsekar 2017; Maldonado 2018), downstream effects of ill oral hygiene and rotten teeth on our dementia (including Alzheimer's) risk.

Said study by Siraj et al. (2019) reports that rinsing for 1 minute with 0.2% aqueous solution of Stevia leaf extract at night reduces the number of acid-producing bacteria on the subjects' teeth to an extent that abolishes the pH decrease in response to the consumption of their favorite food: sugar. What is interesting here is that similar effects were observed for the full-spectrum stevia extract and a commercially available stevioside-based sweetener the scientists used as a comparison in their study ... Why's that interesting? Because it suggests that major microbial effects of stevia remain intact when the sweet compounds are isolated, packaged with fillers and sold as a sugar-alternative, exactly those products of which I initially warned you that they are not identical to the actually "natural" sweetener stevia rebaudiana | Comment!

References

• Ahmad, Samar Y., et al. "Recent evidence for the effects of nonnutritive sweeteners on glycaemic control." Current Opinion in Clinical Nutrition & Metabolic Care 22.4 (2019): 278-283.
• Cho, Nicole A., et al. "Impact of Food Ingredients (Aspartame, Stevia, Prebiotic Oligofructose) on Fertility and Reproductive Outcomes in Obese Rats." Obesity 26.11 (2018): 1692-1695.
• Nettleton, Jodi E., et al. "Low-Dose Stevia (Rebaudioside A) Consumption Perturbs Gut Microbiota and the Mesolimbic Dopamine Reward System." Nutrients 11.6 (2019): 1248.
• Noble, James M., Nikolaos Scarmeas, and Panos N. Papapanou. "Poor oral health as a chronic, potentially modifiable dementia risk factor: review of the literature." Current neurology and neuroscience reports 13.10 (2013): 384.
• Pacifico, Severina, et al. "New insights into phenol and polyphenol composition of Stevia rebaudiana leaves." Journal of pharmaceutical and biomedical analysis 163 (2019): 45-57.
• Ramos‐Tovar, Erika, et al. "Stevia rebaudiana tea prevents experimental cirrhosis via regulation of NF‐κB, Nrf2, transforming growth factor beta, Smad7, and hepatic stellate cell activation." Phytotherapy Research 32.12 (2018): 2568-2576.
• Ramos‐Tovar, Erika, et al. "Stevia prevents experimental cirrhosis by reducing hepatic myofibroblasts and modulating molecular profibrotic pathways." Hepatology Research 49.2 (2019): 212-223.
• Rojas, Edward, et al. "Stevia rebaudiana Bertoni and its effects in human disease: emphasizing its role in inflammation, atherosclerosis and metabolic syndrome." Current nutrition reports 7.3 (2018): 161-170. 
• Samuel, Priscilla, et al. "Stevia leaf to Stevia sweetener: Exploring its science, benefits, and future potential." The Journal of nutrition 148.7 (2018): 1186S-1205S.
• Siraj, E. Saira, K. Pushpanjali, and B. S. Manoranjitha. "Efficacy of Stevioside sweetener on pH of plaque among young adults." Dental research journal 16.2 (2019): 104.
• Stamataki, Nikoleta, et al. "Beneficial Effects of Consuming a Natural Zero Calorie Sweetener Preload Prior to Lunch on Energy Intake: A Double-blind Randomised Crossover Study (FS18-01-19)." (2019): nzz041-FS18.
• Tonsekar, Pallavi P., Shuying S. Jiang, and Gang Yue. "Periodontal disease, tooth loss and dementia: is there a link? A systematic review." Gerodontology 34.2 (2017): 151-163.

10%(+) Reduction in Testosterone After Glucose and Whey Protein Shakes - Is the Classic #BB Shake Anti-Anabolic?

We're talking about a cross-over study in adolescent subjects and acute changes but that's neither the only nor the most relevant reason you don't have to be afraid of the bodybuilding staple, now. In fact, a closer look at the data seems to suggest that we're talking about a 'protein-anabolic decrease in testosterone'... sounds odd? Well, here's how it may relate to your #androgenReceptors (AR) and eventually your gainz, irrespective of your age, by the way.

I have previously addressed the possible ill effects of very high protein intakes on your testosterone levels - in particular, when those intakes are combined with a caloric deficit and, accordingly, reduced intakes of glucose and fat (re-read "True or False - High or Low Protein Intakes Have Profound Influence on Testosterone, SHBG, Estrogen, Cortisol & Co?" | here)... Now, a new study in Clinical Endocrinology (Schwartz 2019) shows that testosterone ⇆ protein/carbohydrate interactions trigger significant acute decreases in serum testosterone levels in those whose testosterone levels should be soaring: adolescent males.

Read more about studies involving TRT/HRT & co on suppversity.com:

What to expect from normalizing Testosterone

Testosterone Gel Augments 'ur Gainz

PWO T-Increases Don't Determine Your Gainz

The Hormonal + Other Underpin-nings of Gainz

Impressive 12% T-Boost (+20% IGF1) W/ Tribulus

T +/- Exercise to Rejuvenate Old Muscle?!

Needless to say that this raises the question: Does that mean that a classic #bodybuilding staple, the high carb, high protein post-workout shake, will ruin your 'muscle building hormone' (learn more)?

The study Schwartz et al. conducted in twenty‐three adolescent males (12‐18 years old; only those with testosterone levels indicating mid-late puberty were included in the analysis) measured the levels testosterone, as well as luteinizing hormone (LH), GLP‐1 (active), ghrelin (acylated), glucose, insulin and subjective appetite prior (0) and at 20, 35 and 65 minutes after the consumption of a test-beverage; a test beverage that contained...

"...either 1 g of glucose monohydrate (BioShop Canada Inc, Burlington, Ontario, Canada) or 1 g of protein (plain whey protein isolate; BiPro USA) per kg of body weight [...] A noncalorie drink was used as control" (Schwartz 2019).

With a protein content of 90.4% (5.7% moisture, 2.2% ash, 1.18% fat and 0.6% carbohydrates), these test beverages were eventually only 'almost' isocaloric, though: 3.74 kcal/kg body weight for the protein and 4 kcal/kg body weight for the sugar shake is yet not far enough apart to invalidate the study results and the flavor was standardized:

"All beverages were flavoured with 1.5 mL of chocolate extract (Vanilla Food Company) to account for the flavour differences and mixed with 500 mL of water, similar to previous protocols.The whey protein and control beverages were sweetened with 0.2 g sucralose (Tate & Lyle) in order to match sweetness with the glucose beverage. Sucralose was chosen as it has been shown to have no effect on postprandial plasma glucose or insulin. Test beverages were prepared the evening before the study and refrigerated in order to be served chilled the following morning. Participants were served the drink in a large covered opaque cup through a straw" (Schwartz 2019).

In the 3xAM sessions that took place, each after a 12h fast, all participants of this cross over trial had to consume the randomly selected beverages (protein, glucose, control) within 5 minutes. In order to wash away any potential aftertaste, they topped that off with 50 mL of plain water.

Testosterone level changes from baseline to 60 min after ingesting the glucose/protein beverage in pre-early puberty (n = 8) and mid-late puberty (n = 13) | results of a previous study by Schwartz (2015).

Where does the idea of reduced T in adolescents even come from, anyway? Schwartz et al. actually did the study under review as a follow-up to their 2015 study in which they observed an acute decrease in serum testosterone after the consumption of a mixed glucose and protein beverage in order to identify whether glucose and protein, each on its own would have similar or the same ill effects on male adolescents postprandial testosterone levels as the researchers observed them in 2015. Reductions as high as -20% in male adolescents in the mid-late phase of puberty (see Figure on the left).

Since the scientists also speculated that these liquid snacks would have different effects on the subjects appetite and, more importantly, ad-libitum food intake, the boys/young men were fed an ad libitum pizza meal after the final blood draw. In that, the "[p]articipants were instructed to eat [pizza] during the next 20 minutes until comfortably full. Based on prescreening participant preferences" (Schwartz 2019 | Pepperoni pizza (87 g) contained 9 g protein, 6 g fat and 23 g carbohydrates for a total energy content of 180 kcal); three‐cheese pizza (81 g) contained 10 g protein, 6 g fat and 23 g carbohydrate for a total energy content of 180 kcal).

Significant differences in terms of the number of slices of pepperoni and/or three-cheese pizza were not observed. Neither in form of treatment nor baseline body weight. 

In other words, with ~1,300 kcal the pizza love (or rather food intake) of the boys was not influenced by either the beverage or the boys' weight status (F = 2.23, P = 0.14). That's in contrast to the testosterone levels which differed significantly when the scientists compared the testosterone response of overweight and normal-weight adolescents (Figure 1.B).

Figure 1: Differential effects of treatments by weight status (A), overall effect of weight status on plasma testosterone (B).

In that, Figure 1.B seems to suggest that lean individuals (mean BMI = 21.1 ± 0.9 kg/m²) are more susceptible to the detrimental effects of protein/carbohydrate shakes than overweight/obese ones (mean BMI = 29.8 ± 1.2 kg/m²). In fact, though, the differential effects of treatments by weight status that are plotted in Figure 1.A, as well as the lack of an asterisk below the open "normal weight" bar in Figure 1.B tell you that the ostensibly large changes in testosterone the scientists observed in the 12 normal-weight subjects were overall non-significant.

So, being overweight or obese seems in fact to modulate the effects of glucose and protein beverages on adolescents' ... as it is common for every extra pound you carry, negatively.

Table 1:  Baseline levels of appetite‐ and sex‐related hormones (Schwartz 2019); interestingly enough, the level of these metabolically relevant measures didn't change differently for normal- vs. overweight subjects in response to either PRO or GLU.

Does that mean that being fat sucks? Well, let's check if any of the metabolic parameters can explain the difference: At least based on the changes that were reported in the FT, that was not the case - while insulin, GLP1, and ghrelin increased, increased and decreased in response to the beverages, they did so to a similar extent in all adolescents. More importantly, though, ...

...there were no differences in the insulin, GLP1 and/or ghrelin response when comparing the protein vs. glucose beverages.

In the absence of treatment effects on the satiety and hunger hormones, it is no longer that surprising that the scientists didn't observe measurable (and significant) effects on the subjects' pizza intake (reported further towards the beginning of this article) - and that despite the fact that all participants' subjective appetite was decreased after the glucose (no, not the protein) beverage (p = 0.0198 for control and p = 0.0247 for protein).

So what's the main takeaway message, then? Is it "Boys love pizza, no matter what?" 

Well, that could be one takeaway, but I think that Schwartz et al. are right to point towards three other results when it comes to the takeaway messages:

• both, glucose and protein shakes acutely lower the testosterone levels of adolescent males, 
• but the effect is not mediated by the macronutrient composition of the liquid meals, 

Moreover, the levels of testosterone the scientists measured in their young subjects' blood or, rather, the changes that were induced by the protein and glucose beverages did not correlate with the regulation of appetite or food intake. The latter was, however, what the scientists had expected when they planned this follow-up to their previously mentioned 2015 study.

This is not an outlier study and similar effects can be expected in older men: The study at hand has by no means produced revolutionary new evidence. In fact, it rather adds to the results of previous research and the testosterone decline(s) that were observed in Caronia et al. 2013 in men who consumed 75g of glucose and Schwartz' previously referenced study in overweight/obese adolescents from 2015, for example (see previous infobox).

The underlying mechanisms of these effects, however, are still not clear. As the scientists from the University of Toronto point out, the changes may be initiated ....

Table 2: Relationships between testosterone and luteinizing hormone with dependent measures (Δ from baseline means).

"by the intake of glucose or amino acids, particularly leucine, which stimulates rapamycin (mTOR) signalling and subsequent protein synthesis" and/or their "inhibitory effect on adenosine monophosphate‐activated protein kinase (AMPK)," (Schwartz 2019)... 

which should - theoretically - have increased the androgen receptor (AR) mRNA expression (Shen et al. 2014 observed the opposite effect, i.e. AMPK up = AR down in prostate cancer cells and it's likely similar effects will occur in skeletal muscle).

Your androgen receptor status may not just determine how much muscle you gain - the data from Morton et al. seems to suggest that it even determines if you make visible muscle gains, at all (learn more in my August 2018 article with the title "If the Androgen Receptor Response to Training Determines Your Gainz, the Question is: How Can You Optimize 'ur AR Density? Training-, Diet-, and Supplement-Effects Reviewed".

So, does it all come back to androgen receptors? Unlike acute changes in testosterone, the androgen receptor density on your muscles has recently been shown to significantly affect the gains of resistance trained men. I discussed the corresponding study at length in a SuppVersity article from August 2018. What I may or may not have highlighted enough in that context is that...

...any increase in androgen receptor (AR) expression leads to greater testosterone uptake by the muscle tissue which lowers plasma testosterone levels... and that probably to an extent similar to what was observed in the study at hand!

This may also explain why neither glucose nor protein has ever been shown to have anti-anabolic effects. In fact, if their isolated and combined consumption in form of a beverage does indeed increase the AR receptor expression and lower the levels of circulating testosterone only by increasing the amount of T that's bound to receptors, that's even more evidence that, on the endocrine level, both nutrients exert pro- not anti-anabolic effects. Accordingly, the notion that the study at hand would support low-carb keto- vs. classic high protein + low-fat-diets for bodybuilders and anyone else striving for a muscular physique would be fundamentally flawed... but let's not jump to conclusions, here! It will be up to other, long(er)-term studies that include resistance training regimen and more relevant outcomes (=changes in body composition) to say which dietary pattern is best for your gainz - as of now, it seems to make less of a difference than people on either side of the nutritional divide want to make you believe - that is, assuming that the dietary protein and energy intake are equal in a low vs. high carb diet | Comment!

References:

• Caronia, Lisa M., et al. "Abrupt decrease in serum testosterone levels after an oral glucose load in men: implications for screening for hypogonadism." Clinical Endocrinology 78.2 (2013): 291-296.
• Schwartz, Alexander, et al. "Acute decrease in serum testosterone after a mixed glucose and protein beverage in obese peripubertal boys." Clinical Endocrinology 83.3 (2015): 332-338.
• Schwartz, Alexander, et al. "Acute decrease in plasma testosterone and appetite after either glucose or protein beverages in adolescent males." Clinical Endocrinology (2019).
• Shen, Min, et al. "The interplay of AMP‐activated protein kinase and androgen receptor in prostate cancer cells." Journal of cellular physiology 229.6 (2014): 688-695.