Diet products are common in most pharmacies. Consumer demand is one factor, with obesity proliferating to the point where the majority of Canadian adults are now overweight or obese. Compounded with the reality that there are no easy solutions when it comes to weight loss, the weight loss industry is working overtime developing new products. Some healthy skepticism is called for, on the part of both consumers and pharmacists. Given the prevalence and accessibility of pharmacies, pharmacists are well positioned to play an important role in helping the overweight and obese.
Let’s review one product advertised widely in Canada: Chili Burn from the manufacturer New Nordic. The ad has the headline “I hated the extra pounds on my body!” “I’m am really surprised how well the Chili Burn tablets worked!” The ad then makes the following claim:
The product increases the amount of calories your body uses in a day, without any needed dietary changes or added exercises. As your body burns and wastes more calories, you steadily but surely, lose weight.
It sounds too good to be true. Is this product supported by good science? According to the manufacturer’s website, Chili Burn tablets contain the following ingredients:
- green tea leaves 486 mg
- dill 150 mg
- ginger root 50 mg
- chili pepper 12 mg
- peppermint 4.50 mg
It’s the green tea, right?
There’s a substantial body of research that’s looked at green tea and its effects on weight. Green tea contains a number of biologically active ingredients called catechins, which are believed (though not established) to have beneficial effects on weight, inflammation, cardiovascular disease, cancer, and other illnesses. There are about 70-100mg of catechins in each gram of tea, and this varies by tea variety and processing effects. Epigallocatechin gallate (EGCG) is thought to be the most active cachetin. (New Nordic states Chili Burn contains 145mg EGCG per tablet.)
In observational trials, it’s difficult to separate out the effects of drinking tea from other lifestyle behaviours that might also lead to lower weight. So the gold standard to isolate out the effects is a clinical trial – preferably randomized and double-blind, to reduce biases. Interpreting the different green tea trials is complicated by not controlling for cachetins, small study size, and the variety of endpoints (what they measured). A systematic review asks a specific question, collects all the relevant evidence, picks the highest quality trials, and summarizes the data. It’s a tool and process that avoids cherry-picking data, and and summarizes what best evidence says. Conveniently, one was just published.
Phung et al, recently published “Effect of green tea catechins with or without caffeine on anthromopometric measures: a systematic review and meta-analysis.” (Since green tea naturally contains caffeine, and caffeine is also believed to have some effects on weight, it’s thought the combination of green tea plus additional caffeine may have additional effects.) In this paper, the authors searched the medical literature for all trials that studied green tea (with or without caffeine), were randomized, and measured at least one of: body mass index (BMI), body weight, waist circumference, or waist-to-hip ratio. Out of 341 studies originally identified, most (215) didn’t measure catechins, some (58) were not randomized and a few (22) didn’t study humans. After excluding an additional 26 that didn’t measure relevant outcomes, 15 were judged to be of sufficient quality, and included. The median duration of the trials was 12 weeks.
In the pooled analyses, the results were as follows:
- Green tea plus caffeine reduced BMI slightly (0.55), body weight (-1.38kg) and waist circumference (-1.93cm), when compared to caffeine alone. All were statistically significantly, but hardly relevant. Green tea plus caffeine also reduced body weight (-0.44kg) compared to green tea without additional caffeine.
- Green tea without additional caffeine showed no benefit.
The comparison was complicated by the generally weak study designs, and the variety of patients studied. Overall, the green tea, with or without caffeine, was well tolerated. The authors concluded that green tea plus caffeine offer only modest clinical benefits. (It is important to note that patients taking drug-based weight loss products are considered to have failed if they do not lose 2kg after 4 weeks of treatment – which is higher than the benefit observed with the green tea and caffeine. By this standard, green tea would be considered a failed intervention.)
New Nordic Chili Burn contains green tea, but no additional caffeine. Based on the systematic review, we can conclude there is no persuasive evidence to support the use of green tea as a weight loss product. What about the 12mg chili pepper? Unfortunately there’s no credible evidence to demonstrate it has any meaningful effect on weight, either.  And the 150mg of dill? No published evidence of benefit at all.  Ginger? Peppermint? Ditto. 
The bottom line with respect to the ingredients in Chili Burn is there’s no persuasive published evidence to demonstrate that they will have any meaningful effects on weight, either alone or in combination.
So now let’s take a look at some of the claims on the manufacturer’s website, and look at the evidence behind them:
Chili Burn is a 100% natural fat burner, made from safe plants and extracts. The product has been developed based on recent obesity studies that clearly show which natural ingredients burn fat most effectively. There’s no published evidence to suggest that this combination of ingredients can “burn” fat. The second statement is puzzling: “most effectively” compared to what? Based on the published evidence, and even the references cited on New Nordic’s web site, there is no persuasive evidence to suggest the ingredients have any meaningful effects. However, the wording is sufficiently vague that it could be legitimately true, as no claim is made that Chili Burn actually contains the “most effective” natural products.
Chili Burn will increase your body’s calorie expenditure, so calories consumed are used for heat production or for energy, instead of being stored as fat.There is no published medical evidence to suggest this is the mechanism of action. It appears the manufacturer is trying to imply the product will independently change the heat production in your body.
Does Green Tea burn fat? Yes! Recent clinical human studies have clearly shown that consumption of especially green tea extracts reduces body weight, mainly body fat, by increasing thermogenesis and fat oxidation. The active ingredient, responsible for the fat loss, is EGCG. As we’ve learned, there’s no conclusive evidence that green tea has these effects. The Natural Medicines Comprehensive Database, an evidence-based reference on natural products, states, “There is conflicting evidence about the effectiveness of green tea for obesity and weight loss,” and rates it as “Insufficient Reliable Evidence to Rate”. 
Why is Chili used? Chili peppers have a natural ability to burn fat, since they use up calories to produce heat. No evidence was found to support this claim. Chili peppers contain capsaicinoids which, when consumed, bind to pain receptors and give the sensation of heat. That is, they do not produce heat. They give the sensation of heat. No published evidence was identified to suggest chili pepers “burn fat”. Besides, the tablets contain only 12 mg of chili pepper, almost a trace amount.
How much weight can I expect to lose with Chili Burn? Clinical studies have shown that when subjects take between 170 – 300 mg of EGCG (Chili Burn contains 145 mg per tablet), the reduction in body fat over a 12-week period will be between 7-10%. No persuasive published evidence was identified to support this claim with green tea, with or without chili pepper. As the Phung systematic review noted, green tea alone (without additional caffeine, as is the case with Chili Burn) was not associated with any benefit, on any measure of weight loss.
And let’s take a look at one of the claims in the print advertisements:
Clinical studies published in the scientific paper “Obesity” show how this exact amount of chili and green tea reduce body fat.Let’s look at the journal Obesity for this evidence. If we search the term ‘green tea‘, we find 31 results. None study a combination of green tea and chili pepper. If we search the term ‘chili’, we find seven results, with no papers of any relevance. There appears to be no published evidence to support this claim. A check of New Nordic’s own website under the section “Research” also makes no reference to any studies that relate to this specific claim. (A second advertisement from New Nordic points to this paper as the evidence supporting this claim. Unfortunately, that product studied in that clinical trial was a combination of green tea with caffeine, in liquid form. The data from that trial is not relevant to Chili Burn, as Chili Burn is a different formula, without added caffeine.)
Dill is used for its properties on cellulite fat deposits. No published medical evidence was identified that support this statement. 
Is it a case of buyer beware with Chili Burn?
Green tea is a common product targeted to consumers, usually with claims that it produces weight loss. A quick skim of the Federal Trade Commission’s website on green tea illustrates how companies continue to be prosecuted for making inappropriate efficacy claims. Importantly, Chili Burn, at the time of writing, has NOT been approved by Canada’s Natural Health Products Directorate (check here). This means a formal evaluation of its safety and efficacy has not been completed. This also means that based on the recent guidance issued to pharmacies by Canada’s pharmacy regulators, Chili Burn should not be sold in Canadian pharmacies.
If you like drinking green tea, and want to lose weight, great. Green tea is probably a much better substitute for calorie-laden beverages. Based on the published evidence, however, there isn’t any compelling data to suggest green tea supplements, like Chili Burn, will have any independent effects on any obesity measure.
Obesity is the second-most preventable cause of death in the world. Pharmacists are ideally positioned to play meaningful roles in assessing overweight and obese patients, referring when appropriate, providing science-based information, and supporting patients that take action. Supplement manufacturers, exploiting the low standards for safety and efficacy for natural health products and supplements, have created a weight loss mirage that seems to be gaining prominence on pharmacy shelves.
There is no published evidence that examines the specific combination of ingredients in New Nordic Chili Burn. Looking at the individual ingredients, there is no persuasive scientific evidence to suggest that any component will cause any meaningful weight loss. In fact, there’s no evidence to suggest any supplement will cause weight loss without dietary changes and/or exercise.
Fundamentally, weight loss can only result from long-term changes to caloric balance. The biggest barrier for many is not the initial weight loss – the challenge maintaining that weight loss on a long-term basis. There is no cure for obesity. Permanent weight loss requires permanent lifestyle changes. There are no quick fixes found in bottles on pharmacy shelves. These products are an oasis that distract from the science-based reality of obesity management.
Interested in learning about the science of weight and obesity? These blogs and resources are highly recommended:
 Natural Medicines Comprehensive Database [Internet Database]. Stockton, CA. Therapeutic Research Facility. (Updated periodically). Accessed 2009-04-05.
 Phung, O., Baker, W., Matthews, L., Lanosa, M., Thorne, A., & Coleman, C. (2009). Effect of green tea catechins with or without caffeine on anthropometric measures: a systematic review and meta-analysis American Journal of Clinical Nutrition, 91 (1), 73-81 DOI: 10.3945/ajcn.2009.28157