Carb Blockers

Carb blockers are a common form of diet pills that are marketed as being able to help dieters to overcome their obesity and excess fat by delaying or preventing the carbohydrates consumed in foods from being absorbed into the body.

The claim regarding carb blockers is that they are, in essence, enzyme inhibitors. They function by reducing the production or presence of the enzymes that are required for the breakdown of carbohydrates by the body, such as amylase and alpha-glucosidases. The majority of these products use a type of protein extract from white kidney beans as their primary active ingredient. Though there are other ingredients used, this is by far the one that is most commonly found in this type of product.

There have been some studies that support the claims regarding carb blockers based on white bean extract. For example, one report in the Journal of the American College of Nutrition detailed the research performed in a physiology study from the Georgetown Medical School, which said that it does have some practical use in a clinical sense, and they found that in people and animals, the ingredient does work.

However, at the same time, the U.S. Food and Drug Administration, and other highly respected health authorities, such as the Mayo Clinic, make statements in the opposite direction. Those who do not believe that these ingredients are beneficial to dieters have stated that the claims made by many of these products simply aren’t true. The reason isn’t that the ingredient doesn’t block the enzymes – which it does – but that the body simply produces far more than the capacity of the products to block them in any meaningful way. So while the ingredient may function as promised, its effects are weak enough that no measurable benefit will result.

According to research from the Mayo Clinic, to have any beneficial effect, approximately 4000mg to 6000mg of the phaseolamin (the substance in the white bean extract that blocks the enzymes) would be required to effectively inhibit enough starch digestion to produce measurable results. Unfortunately, the average carb blockers contain 500mg or less of white kidney bean extract, meaning that the results they produce would be statistically insignificant. Moreover, the study also showed that even if dieters are given enough of the substance to reduce carbohydrate digestion, the result did not produce weight loss.

The FDA has been sending warning letters to the manufacturers and marketers several carb blockers, cautioning them that their claims are false or misleading and that they have not been supported by reliable scientific evidence. One of the most widely publicized incidences was in 2004, when the now-discontinued TrimSpa Carb Blocker makers received such a warning letter.