Product Tests Select a Review CL Answers  Warnings  Encyclopedia Where to Buy News

ConsumerLab.com Answers  

Question:
Can white kidney bean extract really help me lose weight?

Answer:
Supplements containing extracts made from white kidney bean (Phaseolus vulgaris) are promoted for weight loss because they are thought to act as "starch blockers" by inhibiting the starch-digesting enzyme amylase which otherwise turns the starch you eat into absorbable sugar. However, as discussed in the article on ConsumerLab.com, the effectiveness of this approach is questionable. Benefits have only been shown in short-term studies.

Clinical Evidence:
A review of six clinical trials of white kidney bean extract with no other weight loss ingredient in daily doses of between 445 mg and 1,500 mg per day found a statistically significant reduction in body fat (averaging about 4 pounds) when compared to placebo, although there was insufficient evidence to demonstrate weight loss (Onakpoya, Br J Nutr 2011). Three of the studies used the branded extract Phase 2 (Pharmachem Labs). Most were funded by the makers of the extracts, were short in duration (about one to two months) and included lifestyle interventions such changes in diet or exercise.

A review (funded by Pharmachem Labs) of ten clinical studies using Phase 2 (including the studies mentioned above) at doses between 445 mg and 3,000 mg per day concluded that the extract "promotes weight loss when taken concurrently with meals containing carbohydrates." (Barrett, Nutr J 2011). Most of the studies were randomized, double-blind and placebo controlled and ranged in duration from one to three months; however, most of the studies also incorporated diet and/or exercise changes, and several included products which contained additional weight loss ingredients, such as chromium picolinate, inulin, or Garcinia cambogia. Several small, preliminary studies in this review also suggest Phase 2 may help to lessen increases in blood sugar after meals. A more recent, company-funded study among 123 overweight men and women found those who took 1,000 mg of Phase 2 white kidney bean extract three times daily with meals (on a reduced-calorie diet) for 3 months lost significantly more weight compared to those who took a placebo (an average loss of 6.5 lbs. vs. 2 lbs., respectively) (Grube, Obesity 2014). During a 5 ½ month follow-up period after the initial study, 36 of 49 participants who chose to continue to taking the same daily dose of extract without dietary restrictions maintained their weight, but did not lose more weight. The researchers noted that adverse events reported during the study were not severe, serious, nor related to the use of the extract. 

In the U.S., Phase 2 makes the following claims (which the FDA has not objected to):

"May assist in weight control when used in conjunction with a sensible diet and exercise program,"

"May reduce the enzymatic digestion of dietary starches."

Canada allows the following claims for Phase 2 Carb Controller:

"At 6 capsules (3000 mg) per day: Assists in weight management when used with a program of reduced intake of dietary calories and increased physical activity."

"At 4-6 capsules (2000-3000 mg) per day: Provides support for healthy glucose metabolism following a carbohydrate rich meal."

The European Food Safety Authority (EFSA) concluded there was insufficient evidence "to establish a cause and effect relationship between the consumption of the standardized aqueous extract from white kidney bean (Phaseolus vulgaris L.) and reduction of body weight." (EFSA 2014).

Safety and Side-Effects:
White kidney bean extracts have been shown to be safe in short-term studies - the most common side effects being mild gastrointestinal symptoms such as gas and bloating, which tends to occur early on. Phase 2 is FDA GRAS (Generally Recognized As Safe). However, people who are diabetic, or who have kidney or liver disease should consult their physician before using. It should not be taken by women who are pregnant or breastfeeding (Health Canada 2013).

Dosage:
In clinical studies, Phase 2 has been taken in doses of up to 3,000 mg per day, typically in divided doses before meals, for up to 8 months for weight and/or fat loss or weight maintenance. A single dose of 2,000 to 3,000 mg taken with a meal may lessen increases in blood sugar after the meal. Dosage should not exceed 10 grams per day.

The bottom line:
Taking white kidney bean extract before meals may help fat loss (particularly if you eat a high starch diet) and, if combined with a sensible diet and exercise, with modest weight loss. Other than some initial gassiness, it is likely to be safe. Long-term efficacy and safety, however, have not been evaluated.

You can find information about other popular weight loss ingredients in ConsumerLab.com's  Weight Loss Supplement Review, Garcinia Cambogia Supplements Review, Green Coffee Bean Extract Supplements Review, CLA Supplements Review, and Green Tea Supplements Review.



See other recent and popular questions >>
COMMENTS


Share your thoughts and comments about this topic in the space below. Please abide by the following rules:
  • If you make a statement of fact, such as whether a type of treatment does or does not work, state your basis -- such as personal experience or a published study.
  • If you make a positive or negative comment about a product, note whether or not you have a financial interest in the product or in a competing product.
  • Please be respectful in your tone.
  • Please do not submit any type of HTML markup or scripting as it will not be accepted, nor will comments that exceed 2,500 characters.
Comment:

Share your thoughts and comments about this topic in the space below. Please abide by the following rules:
  • If you make a statement of fact, such as whether a type of treatment does or does not work, state your basis -- such as personal experience or a published study.
  • If you make a positive or negative comment about a product, note whether or not you have a financial interest in the product or in a competing product.
  • Please be respectful in your tone.
  • Please do not submit any type of HTML markup or scripting as it will not be accepted, nor will comments that exceed 2,500 characters.
Comment:

You can modify your comment below. Please be aware the comment will have to approve the changes before they will be shown:
Comment:

Your edit has been submitted and is being reviewed by ConsumerLab.com prior to publication.
This CL Answer initially posted on 3/23/2014. Last updated 8/8/2017.
ConsumerLab.com members may submit questions to CLAnswers@ConsumerLab.com. We read all questions and try to answer those of popular interest.

 
Popular Reviews
CoQ10 and Ubiquinol Supplements
CoQ10 and Ubiquinol Differ in Quality, Absorption & Cost
Turmeric and Curcumin Supplements and Spices
31% of Turmeric/Curcumin Products Fail CL's Tests
Green Tea Supplements and Drinks
Check the Strength and Purity of Green Tea Supplements, Teas, and Drinks


ConsumerLab.com Encyclopedia

In addition to our product reviews our encyclopedia covers the following:

Follow us on...

 
 
Join |  Sign In
   
Join Us on Facebook! Join Us on Instagram! Join Us on Twitter! Join Us on Google+! Join Us on YouTube! 
Product Tests
Brands Tested
Health Conditions
Encyclopedia
CL Answers
Clinical Updates
News
Recalls & Warnings
RDAs
Where to Buy Products
Raw Materials Tests
Testing Program
Join CL Today
Testimonials
Join Free Newsletter
Group Subscriptions
Gift Membership
About Us
The CL Seal
CL Survey
Privacy Policy
Sitemap
Contact Us/Help

©2017 ConsumerLab.com, LLC. All rights reserved. A single copy of a report may be printed for personal use by the subscriber. It is otherwise unlawful to print, download, store or distribute content from this site without permission.
ConsumerLab.com name and flask logo are both registered trademarks of ConsumerLab.com, LLC. This site is intended for informational purposes only and not to provide medical advice.