White Kidney Bean Extract: A Quick Weight Loss Fix

After the rage ‘Fat makes you fat!’ was mellowed down, carbohydrates received their fair share of the blame game.

So the best advice given on this was to skip carbs to lose weight. (Read Atkins diet: Does It Really Help In Weight Loss?)

However there are some who just can’t live without carbohydrates like forsaking bread and pasta is indeed a tough job.Nevertheless scientists took this issue up as a challenge and came up with a dietary supplement ‘White Kidney Bean Extract’.

But before we get to what that is, let’s just refresh our knowledge about carbohydrates and weight gain.

How do carbohydrates cause weight gain?

white kidney bean image 1Firstly not all carbohydrates cause weight gain. Refined carbohydrates like refined grain products, sugar and added sugars cause weight gain and not healthy carbs like fruits and whole grains.

When you consume products rich in sugar or starch your blood sugar rises and to counteract that your insulin level rises. Part of this sugar is used as energy and excess is stored as fat.

Immediate rise in insulin levels causes blood sugar levels to drop. Your body is tricked to believe that you are hungry.
Also excess consumption of refined carbs makes your cells insensitive to insulin leading to increased fat deposition.

Also sugars are addictive and excess sugar does translate to high calories. However with complex carbohydrates like those in fruits this is not the case, the sugar is released very slowly and along with minerals and vitamins which does not cause insulin spikes.

Read more details about this in our article Carbs: Tipping The Scales Towards Weight Loss.

How does white kidney bean extract work for weight loss?

Carbohydrates are considered as the largest source of calories. Before being absorbed by the body, carbohydrates are broken down into their simplest structure- monosaccharide.

Two enzymes with the name amylase and glucosidase aid in breaking down carbs.

Initially breakdown begins in the mouth by amylase present in the saliva and then this breakdown is stopped in the stomach due to acidic conditions.  In the intestine, the conditions are neutralized and the borders of small intestine secrete glucosidase enzyme while the pancreas delivers amylase.

Amylase breaks down carbohydrates into oligosaccharides (multiple units of monosaccharide) while glucosidase further breaks it down to monosaccharide. These units are then taken to the liver where they are used as energy or stored as fat.

Many plant derived compounds have been identified as alpha-amylase inhibitors. Common bean (Phaseolus sp.) has 3 forms of alpha-amylase inhibitors: alpha-A1, alpha-A12, and alpha-AIL.

These bind to the enzyme and prevent it from digesting complex carbs. These carbs don’t get absorbed and this blocks the calories contributed from carbs.

Also since the absorption of carbs is slowed down, insulin spikes are avoided and fat accumulation is reduced.

Resistant starch are the type of carbohydrates that cannot be digested and they move unchanged to the large intestine where they serve as a probiotic and offer little or no energy.

By blocking the digestion of complex carbs, white kidney bean extract also makes the carbs undigestable and they to serve in reducing energy content like resistant starch.

What does this mean?
White kidney bean extract inhibits the activity of alpha-amylase enzyme that is necessary for breaking down carbs and absorbing them in the body. It does so by:

  • Preventing digestion of  complex carbs
  • Slowing down absorption of carbs and reducing insulin induced fat accumulation
  • Causing undigested carbs to serve as probiotic and ultimately reduce energy content of meal

white kidney bean featured image

What does science have to say about white kidney bean’s role in obesity?

White kidney bean extract’s ability to block carb absorption has been greatly researched upon and it is included in a number of dietary supplements.

Clinical trials show that white kidney bean extract causes weight loss

In a 4 week clinical trial , participants were given white kidney bean extract (1000mg) or placebo (a fake pill) twice a day. The active group lost 6 pounds and 2.2 inches while placeo group lost 4.7 pounds and 2.1 inches.

The differences between the groups were thought to be insignificant but when only participants consuming a large amount of carbohydrates in both groups were considered, significant reductions were observed (weight: 8.7 pounds vs. 1.7 pounds, waist: 3.3 inches vs. 1.3 inches)

Celleno et al demonstrated that 445 mg of white kidney bean extract taken for a month with carbohydrate rich diet leads to significant loss of fat mass while maintaining lean mass.

Phase 2 is the water extract of the white kidney bean that serves as alpha amylase inhibitor and is sold as a dietary supplement.

Phase 2 was earlier sold as Phaseolamin 2250, referring to 1 g of the product blocking 2,250 starch calories.

A clinical trial  investigating the effect of Phase 2 on body weight resulted in average weight loss of 0.47 pound per week in 8 weeks. A decrease in blood lipid levels was also observed.

A review  of clinical trials by Onakpoya et al reveals that white kidney bean extract favors fat loss significantly over placebo but better quality clinical trials are required to give a strong conclusion.

The famous review by Barret and Udani on the weight reducing effect of white kidney bean extract also suggests that white kidney bean has the potential to reduce weight and improve blood sugar control when taken with carbohydrate rich diet.

This review was sponsored by PharmaChem laboratories (manufacturers of Phase 2) but this paper  is a must read if you have any doubts regarding efficacy of white kidney bean extract on weight management for it covers a great number of studies on the same showing positive results.

What does this mean?
Results from clinical trials and review of clinical trials strongly suggest that white kidney bean extract can induce weight loss when taken with carbohydrate rich meal.

It controls appetite

In an animal study  it was found that administration of white kidney bean extract led to reduced weight gain, reduced food intake and improved blood sugar control.

Similar results were reported by another animal study  but here scientists suggested that in addition to inhibiting alpha amylase, the white kidney bean extract stimulated release of cholecystokinin from the intestinal cells.

Cholecystokinin is a hormone that digests fat and protein and also suppresses hunger.

What does this mean?
Animal studies show that white kidney bean extract has an appetite suppressing effect which can reduce your energy intake.

It reduces cravings

White kidney bean extract is proven to reduce food intake so scientists decided to investigate whether it reduces addiction towards highly palatable foods.

In this animal study , mice were provided access to regular food pellets and highly palatable foods like butter cookies, condensed milk beverage and chocolate milk beverage. They were treated with white kidney bean extract.

Decrease in appetite was observed in all groups. Additionally white kidney bean extract reduced the rewarding effect of highly palatable foods suggesting its use in treating overeating and food craving.

Similar results were reported in another study  where a 40% reduction in craving for chocolate flavoured beverage was brought about by white kidney bean extract.

What does this mean?
White kidney bean extract interferes with the mechanism involved in food addiction and overeating and there by reduces cravings for highly palatable foods.

It improves metabolic parameters

Animal study reports that white kidney bean extract leads to enhanced blood sugar control in diabetes.
Other studies show that white kidney bean extract reduces lipid or fat accumulation and the risk for developing heart diseases.

What does this mean?
White kidney bean extract can reduce parameters associated with metabolic syndrome and diabetes.


White kidney bean extract or Phase 2 is available as powder, tablets, capsules and chewables. The dosage  is 1-2 capsules containing 500mg which is taken 3 times a day prior each meal. That would be around 1500-3000g a day.

Doses upto 10 g a day are proven to be safe.


No serious side effects  have been reported due to consumption of white kidney bean extract. Slight gastrointestinal side effects such as bloating, flatulence, diarrhoea may occur but they are temporary.

Raw beans contain compound called phytohemagglutin which is toxic and cause clumping of red blood cells. However Phase 2 is a standardized extract which inactivates such compound.

Consult your health physician before taking any supplement.


White kidney bean extract induces weight loss by mimicking a way of creating calorie deficit by leaving carbs undigested and relatively unabsorbed from meals. However there are two things that you need to consider:

This would help in weight loss only if you come consume a high carb diet. It blocks digestion of complex carbs only and not sugars. In other words it won’t protect you from weight gain by consuming sugar and added sugar products.

Second thing the weight loss is only for short term. Taking any supplement for long time can pose risks.

Apart from that white kidney bean extract is protective against colon cancer and aids in better sugar control in diabetes.

As per scientific studies, white kidney bean extract shows good weight loss potential. You can expect modest weight loss outcomes when taking white kidney bean extract but then again the effect is temporary. If you stop taking it and eat a high refined carb diet you are likely to gain weight.

Initial weight loss by taking this supplement followed by a low calorie diet for the weight management phase would deliver better results.

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