Green Coffee Extract–Weight Loss Truth or Myth?

It is no new news that overweight and obesity rates continue to increase not just in the U.S but also worldwide. With concern for good health and hope to achieve faster and better weight loss results, the use of dietary supplements has also increased among consumers. Current scientific research finds most of the supplements to be ineffective for many reasons. Some may not contain the adequate dosage to produce a positive effect on health, some may be poorly absorbed and others may become inactive in the presence of other substances. One “slimming” supplement worth discussing because of the gained popularity among dieters in the recent past years is the green coffee extract (GCE) dietary supplement. After being endorsed by celebrity health experts and extensively marketed by well-known manufactures, the sales of green coffee extract as a weight-loss aid have skyrocketed.

But what is green coffee extract?
Green coffee extract (GCE) is present in green raw coffee beans. It is also present in the roasted coffee but much of the GCE is destroyed. The major GCE constituent is cholorogenic acid (CGA). It is estimated that 100 grams of raw coffee can provide about 5 to 12 grams of CGA. Besides coffee, CGA can be found in many fruits and vegetables. Research indicates that CGA is highly absorbed and metabolized in humans; however, there is large variation among individuals on how much is absorbed in the body.

Green coffee extract has been marketed as a weight loss supplement in the capsule form under a wide variety of brands using the patented name Svetol. In the U.S market, Svetol – manufactured by the French company Naturex, is listed as an active ingredient on 25 dietary supplements. Svetol is also found in Norwegian Coffee Slender products such as instant coffee, decaffeinated tablets and mints, and chewing gum.

What are some of the suspected benefits of cholorogenic acid (CGA)?
The chlorogenic acid in the green coffee extract is believed to have antioxidant properties and in animal studies, it has been shown to inhibit fat accumulation. In humans, the consumption of caffeinated coffee can lead to long-term weight loss; this is believed to be a result of the effects of caffeine intake possibly working along with green coffee extract on metabolism.

The findings of current research indicate, but not convincing evidence, that intake of green coffee extract fortified with chlorogenic acid may promote weight loss. These results must be interpreted with caution, as the methodology in many studies is poor and further investigation is needed. More rigorous trials with larger sample size and longer duration are required to assess the effectiveness and safety of green coffee extract as a weight loss supplement.

As a consumer, you have the power of your purchasing decision. However, informed choices can prevent you from wasting your money on products that may not give the expected results and that may have long-term adverse effects on your health and body. The best approach to avoid weight gain or promote weight loss, one must use all the calories consumed on a daily basis. Researchers, physicians, registered dietitians and dietary supplement industry agree that eating a variety of whole foods, practicing portion control and exercising regularly is the foundation to maintaining a healthy weight.

Thank you I.I. UTHSCSA Dietetic Intern, March–2013

1. Onakpoya I, Terry R, Ernst E. Use of green coffee extract as a weight loss-supplement: A systematic review and meta-analysis of randomized clinical trials. Gastroenterol Res Pract. 2011; 2011:1-6.
2. Vison J, Burnham Bryan, Nagedran M. Randomized, double-blind, placebo-controlled, linear dose, crossover study to evaluate the efficacy and safety of a green coffee bean extract in overweight subject. Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy. 2012; 5:21-27.

Energy and Caffeine

You see the commercials every day: energy shots, drinks, and supplements are touted on the airwaves as the cure-all solution for low energy and poor concentration. They claim to enhance everything from mental alertness to increased performance and boosted metabolism. But what do they put in these products and do they really work?

It turns out that the jolt of energy promised is based on two main ingredients: sugar and caffeine. Energy drink companies are quick to highlight the added B-vitamins and other nutrients that are thrown into the mix – but these vitamins and nutrients will only affect your energy and metabolism if you have a nutrient deficiency; which, thanks in part to the fortification of foods in the United States, most Americans do not. On the other hand, the main ingredient of caffeine is a known central nervous system stimulant, and can therefore increase feelings of alertness and decrease the perception of effort. This effect can be traced to a compound that prepares the body for sleep, called adenosine. Adenosine is shut out of the brain in the presence of caffeine, as caffeine “hogs” the brain’s receptors that usually pick up adenosine. When caffeine is picked up by the brain, adrenaline is released, which ultimately increases the body’s perception of having more energy. Numerous studies suggest that caffeine can also improve athletic performance and endurance with as little as 2 cups of coffee one hour prior to exercise. However, every individual exhibits a different response to caffeine and may experience varying degrees of stimulation, or lack thereof.

Due to these physiological effects on the body, caffeine is considered a drug – albeit a naturally occurring one – and has been classified as a controlled substance by the National Collegiate Association of Athletics (NCAA). Until 2004, caffeine was even banned by the International Olympic Committee (IOC) and World Anti-Doping Agency. There is little evidence to support that caffeine use results in the physical and social consequences associated with serious drugs of abuse, but if caffeine intake is abruptly stopped or altered, sensitive individuals may experience headaches, drowsiness, irritability, and/or restlessness. These symptoms typically last for a short time-period of 2-3 days and can be avoided by gradually reducing caffeine consumption over several days.

In moderation, most people will not experience detrimental effects to the body from consuming the amount of caffeine in the average energy drink or energy shot. However, too much caffeine, which can stem from consuming just a few of these drinks, can produce unwelcome side effects such as anxiety, jitteriness, rapid heartbeat, gastrointestinal distress, insomnia, dehydration, and even decreased energy. Excess caffeine from energy drinks can be potentially dangerous in sports, especially in combination with alcohol and other stimulants. Side effects can also occur from the overconsumption of coffee, therefore, moderate caffeine consumption is recommended at 200-300 milligrams, or the equivalent of 2-3 cups of coffee and 3-4 cups of black tea.

If you have low energy and/or reduced concentration, consuming caffeine is not the ideal way to compensate. Rather, it is a temporary solution to lack of sleep and an imbalanced diet. Instead, the Academy of Nutrition and Dietetics recommends limiting screen time, setting and enforcing a regular bedtime, engaging in calming activities before bedtime, and following a well-balanced nutrition plan that includes plenty of water. You can also exercise or eat several smaller meals throughout the day rather than three larger ones. Finally, if you feel you are getting too much caffeine in your diet, the Academy recommends mixing half decaf and half regular coffee together, or substituting coffee with decaffeinated and herbal teas.

Thank you M.M., UTHSCSA Dietetic Intern


Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. J Am Diet Assoc. 2009;109:509-527.

Ellen Coleman, RD, Back to the Grind: The Return of Caffeine as an Ergogenic Aid
Today’s Dietitian. Vol. 11 No. 3 P. 8

Elizabeth Lee and Kathleen Zelman, RD: Energy Shots Review: Do They Work? Are They Safe?

Academy of Nutrition and Dietetics: Running Low on Energy? Catch Those Zzz’s

Academy of Nutrition and Dietetics: How Much Caffeine is Too Much?

How Do Energy Drinks Work?

Caffeine Fuels Most Energy Drinks

International Food Information Council Foundation: Everything You Need to Know About Caffeine

Sports dietitian Nancy Clark, M.S., R.D: The facts about caffeine and athletic performance