Today, the most sought after goal in the fitness industry is to “lose fat”. Just refer to the countless upon countless magazines or advertisements boasting “revolutionary new ways to absolutely melt off fat forever”! Fitness industry professionals have been peddling pills and secret solutions for a very long time. And it works. These diet pill fads have grown to a billion dollar industry marketed at beginners and the uninformed. Watch this clip promoting the use of “metabolic boosting pills” by Dr. Oz and ask yourself if it doesn’t sound enticing, considering this man’s impeccable Ivy-League credentials.
These unsubstantiated claims and several more actually caught Dr. Oz a lot of flack in the scientific community, leading to a Senate Commerce subcommittee hearing on June 18, 2014. He agreed to the Senators that many of these weight loss supplements were unrealistic and since 2014 his influential show dialed down on miracle pill pushing.
Even though the worst offender backed down, it doesn’t take very long to find countless miracle pill ads across the internet. A culture of blindly following scientific-sounding pseudoscience has only exacerbated this issue further. One only needs to see the plethora of ads claiming “Doctors HATE him: Lose 20 pounds in JUST A WEEK”, to prove that the fitness industry actively tries to reject scientific truth. It’s hard to blame them too… after all, who would want to WORK for a great body, PAY for a gym membership, and DIET, when you could just binge watch Netflix and “shed fat forever”.
The truth hurts, yes, but lies could hurt even more. Some diet pills marketed in the past have reported to cause severe damage to the human body. One diet pill fad of the early 2000’s- Ephedra- lead to severe blood pressure, cardiovascular, and kidney issues in users. While this case is well documented, and Ephedra products have since been banned, the risks of taking over-the-counter diet supplements remains the same. the FDA does not test all weight loss products for safety, so there’s no guarantee that each new “miracle” ingredient in the supplement is safe. This is because those herbal supplements are just that– supplements. Not, I repeat NOT, medically approved medicine. There exist medically prescribable prescription medicines for weight control, but these must be taken with the prescription and observation of a medical doctor.
No amount of weight loss pills or powders will make you look like a Baywatch extra. If fat loss is the goal, pill popping, even to excess, is not going to be enough. There just aren’t any safe, natural “fat burning” compounds powerful enough to, on their own, cause meaningful weight reduction. But it would be a lie to say that all supplements are basically useless and unsubstantiated WITHOUT analyzing the scientific evidence. The fitness community needs a scientific detox, so I examined the scientific literature on some of the most popular natural fat loss supplements: Caffeine, Green Tea Extract, Yohimbine, Garcinia Cambogia, ALA, CLA, and L-Carnitine. The evidence found in this article was gathered through the use of the reputable nutritional science aggregator Examine.com.
Of all the supplements in this list, the effects of caffeine have been the most well documented. Research suggests that caffeine antagonizes adenosine receptors. Adenosine causes sedation and relaxation when it attaches to its receptors. Its inhibition by caffeine results in a clear boost in alertness and energy. Scientific study has proven that caffeine ingestion does indeed provide for a slight increase of fat oxidation and a thermogenic response (AKA “fat burning response”). A study by Belza et al., suggests that Caffeine induced a thermogenic response of 6% above baseline value compared to placebo, meaning that caffeine did minorly increase resting fat metabolism to a measurable degree. While there remain uncertainties about the precise function of caffeine, a paper by LeBlanc et al. suggests that “caffeine ingestion is related to an enhanced lipid mobilization, possibly produced by a greater epinephrine secretion and by subsequent increased lipid oxidation”. To put it simply, caffeine can lead to increases in fat loss, but the effects are still considerably minor. Furthermore, caffeine usage in humans test subjects is prone to tolerance. This means the effects of caffeine will be diminished, often to the point where the only benefit a user experiences is caffeine’s anti-sleep effect rather than its fat loss effects. The exact metabolic reasons for the formation of a caffeine tolerance is not certain, however you can be cetain that while it might offer some help with fat burning and energy, it is not a miracle supplemenrt by a long shot.
Green Tea Extract
Green tea extracts is a controversial supplement, largely due to its seemingly large variability in responses in test subjects. Green Tea itself lends most of its benefits through water-soluble polyphenols (frequently referred to as catechins) present in the leaves. A regular cup of green tea contains an inconsequential amount of catechins, however through extraction, higher concentrations can be sold as supplements. A study by Dean et al. suggests that the Green tea catechin EGCG at a concentration of 270 mg does not provide any noticeable difference in male subjects. However, at much higher concentrations, green tea does prove effective towards fat oxidation. A study by Venables et al. showed evidence that green tea extractions at about 1256 mg provide an “average fat oxidation rates of 17% higher after ingestion of GTE than after ingestion of placebo. Moreover, the contribution of fat oxidation to total energy expenditure was also significantly higher, by a similar percentage, after GTE supplementation”. So not only did the green tea extraction provide significant supplementation, but it also resulted in higher energy output during a workout. To give some perspective, the average number of catechins in a cup of Lipton Green Tea is 30 mg, so this supplementation is approximately equivalent to 42 cups of green tea. So there is evidence that this supplement is not complete nonsense, however, the major issue with over the counter products is that you can really NEVER be certain of how much of the supplement is in one pill. The FDA does not regulate this industry very diligently, so even if a product markets 1000 mg of green tea extract, it is very difficult to be certain of the product’s consistency. More often than not, these pills are adulterated and might not deliver their intended intensities.
Green tea extract also is prone to tolerance and can cause severe liver damage when abused. The exact mechanisms of tolerance building are not completely understood, but the takeaway is that the effects of green tea extract supplementation is not long term and definitely not the miracle supplement that it is marketed as. At high dosages of catechins and EGCG, a study by Sarma et al, 2008 suggests that at very high doses EGCG and the other catechins in green tea act as pro-oxidant redox cyclers, depleting liver reduced glutathione with similar consequences as acetaminophen overdoses. In simpler words, overdosing on TYLENOL is similar to over consuming high amounts of GTE! Is such a minor kick start really worth potential liver toxicity?
Yohimbine is a compound derived from the bark of the central African tree, Yohimbe. Companies selling the product claim that the compound is used to promote fat loss during short term fasting. It has been noted however that any perceived interactions caused by Yohimbine are negated by food consumption. Therefore, there is very little if any evidence that this compound provides any sort of fat loss. The one source that many companies pushing the product cite is a study by Ostojic SM from 2006 that measured the effect of 20 mg of yohimbine on “elite male soccer players”. The study had a control group of 10 players and a test group of 10 players – so it was clearly extremely thorough. The study produced statistically questionable data that showed a drop of about 2% in body fat among the test group. Another more thorough study on the compound by Sax L in 1991 produced evidence that there was absolutely no evidence of fat loss for obese males. A group of 47 obese men participated in the study, and orally consumed 43 mg of yohimbine, yet did not see any noticeable fat loss whatsoever. At a concentration nearly double to the questionable article often cited promoting yohimbine, there is no noticeable difference through its usage. Even if you could get 43 mg of yohimbine, since most yohimbine supplements sold are adulterated, it would not produce any noticeable difference at all.
Not only that, but yohimbine might also be linked to an exacerbation of depression or mania in mentally ill users. Because the compound inhibits alpha-2 receptors, yohimbine usage also causes an increase in blood pressure, insomnia and puts an unhealthy strain on the heart muscles. This is the truth of the fitness industry: peddling potentially dangerous compounds that promise unsubstantiated claims to the buyer.
Garcinia might be the most popular of the diet pill fads, thanks in part to its promotion by Dr. Oz. After he promoted it on his show, people began eating commercial extracts of this Indonesian fruit like candy. The fiasco that this craze caused was a big reason for Dr. Oz’s Senate hearing, as there is very little evidence that even remotely suggests the extract of this plant has fat loss benefits. The reason that this fruit is suggested to be effective at losing fat, is because it contains the chemical hydroxycitric acid, which has been shown to reduce weight gain during periods of overfeeding…in rats. The study famously cited by Oz by Rao N. et al. provides evidence that the compound does in fact result in weight loss for the tested mice. While animal research is valuable for exploring possibilities and uncovering potentially fruitful areas to explore further, our bodies respond very differently to various types of molecules. A meta-analysis of human usage of Garcinia Cambogia by Onakpoya et al. demonstrated very unreliable evidence towards any sort of fat loss results. Of the 23 studies selected over 11 were reported as unreliable sources, and the 12 that were statistically relevant, small sample sizes provided for varied and inconclusive results. Some tests suggested garcinia cambogia use was inconsequential while others showed a tiny amount of fat loss than compared to the control group.
Another spark of controversy surrounding this plant is that it causes liver toxicity when concentrated and consumed at high levels. In supplements marketed with Garcinia Cambogia concentrate, users reported liver toxicity and health complications resulting in hospitalizations. Unsurprisingly, this miracle supplement is also complete bogus.
CLA, or Conjugated Linoleic Acid, is a term that refers to fatty acids that have the general structure of linoleic acid. This Omega- 6 fatty acid commonly found in dairy and meat products, is often marketed in weight loss pills. There exists virtually no statistically replicable data that suggests fat loss can occur through the use of CLA. Most of the weight loss or fat loss studies that study the fatty acid contradict one another. One study by Chen et al. showed evidence of an average of .69 kg of weight loss for an experimental group of chinese males over a 12 week period. However, another study by Joseph SV et al. suggested no change in body composition or fat metabolism in overweight men by consuming CLA. This is despite the fact that the study that was “successful” used 1.7 g of CLA, while the “unsuccessful” study used 2.7 grams of CLA. The discrepancies and inconsistencies published regarding CLA are among its only consistencies, therefore it is highly unlikely that it will aid in fat loss. Nevertheless, that doesn’t deter Dr. Oz and other fitness gurus to peddle the fatty acid as a weight loss supplement.
ALA, or Alpha-lipoic Acid, is a mitochondrial fatty acid that is useful for energy production within the cell. A healthy human body naturally produces ALA, and enough of it for its intended metabolic function. Supplementing high doses of the fatty acid have proven no definitive results for fat loss in moderately overweight or healthy subjects, and like CLA, studies often contradict each other. The antioxidant is usually marketed as a metabolic booster, fat burner, and energy booster and there is some substantiation to this claim. A popular study by Koh EH et. al. demonstrated that there was a higher average weight drop of about 1 kg higher for a sample of 120 obese individuals who orally consumed 1800 mg of ALA as compared with an obese control group. However, this minor result is hugely misleading. A study by Butler et al. points out that the reduction in weight caused by such a high dosage of ALA had more to do with its minor appetite suppressing effects than with increased fat metabolism. There of course exist more efficient appetite suppressants, however, this does not help Dr. Oz or Bodybuilding.com sell more capsules of ALA. Ultimately misinformation and profit chasing wins out in the fitness industry.
It is not difficult to find scientific data debunking the use of the L-Carnitine as a fat loss product. The compound is found in high concentrations within muscle fibers and is important in the metabolic processes of the mitochondria. However, it is already synthesized in high concentrations by the human body and is therefore extra supplementation is unnecessary and useless for fat loss. A study by Villani et. al. demonstrates that L- Carnitine supplementation in moderately obese women does not promote weight loss at all. Despite this, companies across the internet promote the product for its unsubstantiated weight loss and muscle building potential.
Altogether, these seven commonly marketed “fat burners” sound too good to be true, and are. Apart from losing maybe a pound of fat from high doses of green tea extract and caffeine, no amount of supplementation will reliably lose fat for you. Losing fat is only possible through hard work and dedication, and nothing but proper nutrition and exercise will really show measurable results. The extravagant promises of these supplements are more driven by profit hunger rather than the well being of the buyer – and this has previously lead to dangerous complications from diet pills. So before dropping 60 dollars on FAT–OBLITERATOR–INSTASHRED MAX 9000, maybe just grab a coffee or tea instead.