Listen to this article on Spotify, or watch it on YouTube.
White kidney bean extracts are often called a “carb blocker”. But how does it work, and how effective is it?
In this blog post, we’ll dive deep into the world of white kidney bean extract and explore its benefits, limitations, and tips for use.
What are White kidney beans?
White kidney beans fall under a group of closely related beans known as Phaseolus vulgaris. Phaseolus vulgaris actually refers to the common bean, and includes kidney beans, black beans, pinto beans, navy beans, and many others.
All these beans within the species Phaseolus vulgaris contain enzymes that might be useful in weight loss, however most research studies seem to use white kidney bean extracts. So dietary supplements of Phaseolus vulgaris are mostly extracted from the white kidney bean.
Phaseolus vulgaris
Phaseolus vulgaris, commonly known as the common bean or French bean, includes many popular varieties of beans that are widely cultivated and consumed around the world. Here are some common beans that fall under the species Phaseolus vulgaris and their nutritional differences:
- Black beans: Also known as turtle beans, black beans are small, dark, and have a slightly sweet flavor. They are commonly used in Latin American cuisine, as well as in vegetarian dishes. They are a good source of protein, fiber, and antioxidants.
- Pinto beans: Pinto beans are medium-sized and have a beige color with brown speckles. They have a creamy texture and a mild, slightly sweet flavor. They are commonly used in Tex-Mex cuisine, as well as in soups and stews. They are a good source of protein, fiber, and folate.
- Kidney beans: Kidney beans are large and kidney-shaped, with a reddish-brown color. They have a firm texture and a slightly sweet flavor. They are commonly used in chili, salads, and rice dishes. They are a good source of protein, fiber, and iron.
- Navy beans: Navy beans are small and oval-shaped, with a white color and a smooth texture. They have a delicate, mild flavor and are commonly used in soups and stews, as well as in baked bean dishes. They are a good source of protein, fiber, and folate.
- Lima beans: Also known as butter beans, lima beans are large and flat with a pale green color. They have a creamy texture and a mild, slightly sweet flavor. They are commonly used in stews, casseroles, and succotash. They are a good source of protein, fiber, and iron.
- White kidney beans: Also known as cannellini beans are medium to large in size and have a creamy white color. They have a slightly nutty flavor and a creamy texture when cooked. They are commonly used in Italian dishes such as pasta e fagioli and minestrone soup. They are a good source of protein, fiber, and iron.
Nutritional benefits
White kidney beans are a nutritious and versatile ingredient. Here are some of the nutritional benefits of white kidney beans:
- Protein: White kidney beans are a rich source of plant-based protein, with around 15 grams of protein per cooked cup (177 grams). Protein is essential for building and repairing tissues, and can also help promote feelings of fullness and satiety.
- Fiber: White kidney beans are an excellent source of dietary fiber, with around 12 grams of fiber per cooked cup (177 grams). Fiber can help regulate digestion, promote bowel regularity, and lower cholesterol levels.
- Vitamins and minerals: White kidney beans are a good source of various vitamins and minerals, such as folate, iron, potassium, and magnesium.
- Low in fat and calories: White kidney beans are naturally low in fat and calories, making them a great food for weight management and overall health.
Compared to other legumes
The beans in general have a pretty similar macronutrient profile to each other. Compared to other common legumes, they have a good amount of protein, but also a significant amount of carbohydrate, making them difficult to have on a low carb or keto diet.
Legume | Calories | Protein (g) | Fiber (g) | Fat (g) | Carbs (g) |
---|---|---|---|---|---|
Soybean | 446 | 36 | 9.3 | 20 | 30 |
Chickpeas | 364 | 19 | 10.6 | 6 | 60 |
Lentils | 353 | 25 | 7.9 | 1 | 63 |
Pinto Beans | 347 | 21 | 15.4 | 1 | 62 |
Black Beans | 341 | 21 | 16.6 | 1 | 63 |
White Kidney Beans | 338 | 22 | 10.5 | 1 | 63 |
Lima Beans | 338 | 21 | 7 | 0.9 | 63 |
Red Beans | 337 | 23 | 11.3 | 1 | 62 |
Navy Beans | 335 | 23 | 10.5 | 1 | 63 |
Kidney Beans | 333 | 24 | 8 | 1 | 60 |
Peas | 81 | 5 | 5.5 | 0.4 | 14 |
For weight loss
Including white kidney beans in your diet can potentially help with weight loss in a few ways.
- Firstly, white kidney beans are a good source of fiber, which can help you feel full and satisfied for longer periods of time. This can help to reduce overall calorie intake and prevent overeating.
- Secondly, white kidney beans have a low glycemic index, meaning that they can help to regulate blood sugar levels and prevent spikes and crashes that can lead to cravings and overeating.
- Finally, white kidney beans are a good source of protein, which can also help to promote feelings of fullness and support healthy muscle mass.
Overall, incorporating cooked white kidney beans into your diet can provide a range of nutritional benefits and support a healthy weight loss diet.
Phaseolamin (Carb blocker)
White kidney bean extracts, as well as other Phaseolus vulgaris beans, contain a compound called phaseolamin. This compound inhibits an enzyme in our body called alpha-amylase. Alpha-amylase is an enzyme normally produced by our bodies to help break down carbohydrates like starch.
By inhibiting this enzyme, phaseolamin blocks our bodies from breaking down carbs, and as a result absorbing some of the carbohydrate we eat. The more carbohydrates you block, the less overall calories you theoretically absorb.
We aren’t sure exactly how much carbohydrate is actually blocked from being absorbed, but most real life estimates are pretty small. So it’s also suggested that these extracts may also help reduce appetite, which might also explain its ability to help people lose weight.
Weight loss supplements that extract and concentrate phaseolamin typically use a proprietary extract of white kidney beans, which is standardized to contain a specific amount of phaseolamin. The extract is often marketed under various brand names such as Phase 2 (Pharmachem Labs; also marketed as Starchlite and Phaselite), Carb Intercept with Phase 2 (Natrol LLC), and Beanblock (Indena S.p.A).
Amount in food?
While regular kidney beans do contain the active compound phaseolamin, the concentration found in cooked beans are very low, too low to significantly inhibit carb absorption.
That being said, beans are quite high in fiber and protein. This makes them quite filling and nutritious, making them a good way to increase the fullness of any meal, and reduce snacking afterwards.
So while eating regular kidney beans is not a substitute for white kidney bean extracts that contain concentrated phaseolamin, like taking Phase 2 supplements, beans can still be incorporated into a weight loss diet in controlled portions, to help manage hunger and appetite.
Side effects
White kidney bean extracts are usually well tolerated. However, because it stops your body from absorbing some carbohydrate, the carbs might end up being eaten and fermented by your gut bacteria instead. This might result in some mild diarrhea or constipation, bloating, gas, and stomach pains.
Also, the alpha-amylase inhibitors from white kidney beans orally can cause several gastrointestinal side effects such as nausea, vomiting, diarrhea, flatulence, constipation, satiety, and stomach pains.
From dietary sources
People who consume raw kidney beans may experience some unpleasant side effects, since raw kidney beans contain another compound called phytohaemagglutinin. This toxic compound is found in high concentrations in raw kidney beans, and can cause strong nausea, vomiting, and diarrhea.
This is why you shouldn’t try eating raw kidney beans. Cooking destroys this compound, making cooked kidney beans safe to eat. Canned kidney beans have also been cooked, making them safe to eat straight from the can.
So if you do decide to try white kidney bean extracts, avoid raw or whole kidney bean powders, and look for standardized and properly purified extracts.
Kidney beans also contain complex carbohydrates like raffinose. These complex carbohydrates can be difficult for some people to break down, and instead of being absorbed by our body, are then eaten by gut bacteria, which then produce a bunch of gas as a byproduct. This is why some people experience gas and bloating from eating beans or lentils.
How effective is it for weight loss?
A meta-analysis of six small clinical studies has found that taking oral Phaseolus vulgaris extract daily for 4-12 weeks can lead to a reduction in body weight and waist circumference in overweight and obese adults.
The studies suggest that taking white kidney bean extract 800-1000 mg or cranberry bean extract 100 mg three times daily for 5-12 weeks can reduce body weight by 1.5-4 kg, body mass index by about 0.7 kg/m2, and waist circumference by about 1.5-5 cm when compared with a placebo or other control.
So research seems to suggest that white kidney bean extracts can indeed help some individuals lose weight, amounting to around 4 or 5 pounds over a few months. Most studies use 1 to 1.5 grams of a specific commercial extract, known as Phase 2, before each meal.
However, it only seems to help individuals who are eating a diet high in carbohydrates. This makes sense since it primarily works by reducing carb absorption. If your diet was low in carbohydrate to begin with, there’s not much to block.
White kidney bean extracts likely block only a small percentage of the total carbohydrate eaten, so if you’re not eating a whole lot of carbohydrate to begin with, the total amount of carbs blocked will be small, and it probably won’t have any effect on your weight.
How to use it for weight loss
If your diet is high in carbohydrate, white kidney bean extracts might help promote some modest weight loss.
I would first recommend simply trying to reduce the amounts of carbohydrate you eat, or even consider a low carb diet since those will be much more effective and reliable ways to lose weight.
But if you’re in the process of slowly reducing your carb intake from a high carb diet, it might help improve the effectiveness of that process by a little bit.
However, if your diet is already low in carbohydrate, white kidney bean extracts like Phase 2 might not be very useful for you at all.
If you do decide to try white kidney bean for weight loss, here are some tips:
- Take it with meals: White kidney bean extract is most effective when taken with meals that are high in carbohydrates. This allows the extract to inhibit the activity of alpha-amylase and reduce carbohydrate absorption.
- Use standardized extracts: When purchasing white kidney bean extract supplements, look for those that contain a standardized extract such as Phase 2. This ensures that the supplement contains a consistent amount of the active ingredient and can help to increase the effectiveness of the supplement.
- Try dietary sources: While white kidney beans used in cooking won’t have as much phaseolamin as extract supplements, they are still a nutritious food with plenty of fiber, protein, vitamins, and minerals, and can help to promote feelings of fullness and support healthy weight loss.
Top supplement choices
- White bean (Phase 2) – 2 to 6 caps w/ meals
Learn more about
Citations
Birketvedt GS, Travis A, Langbakk B, Florholmen JR. Dietary supplementation with bean extract improves lipid profile in overweight and obese subjects. Nutrition 2002;18:729-33.
Bo-Linn GW, Santa Ana CA, Morawski SG, Fordtran JS. Starch blockers–their effect on calorie absorption from a high-starch meal. N Engl J Med 1982;307:1413-6.
Boivin M, Flourie B, Rizza RA, Go VL, DiMagno EP. Gastrointestinal and metabolic effects of amylase inhibition in diabetics. Gastroenterology. 1988;94(2):387-94.
Celleno L, Tolaini MV, D’Amore A, et al. A dietary supplement containing standardized Phaseolus vulgaris extract influences body composition of overweight men and women. Int J Med Sci 2007;4:45-52.
Grube B, Chong WF, Chong PW, Riede L. Weight reduction and maintenance with IQP-PV-101: a 12-week randomized controlled study with a 24-week open label period. Obesity (Silver Spring). 2014;22(3):645-51.
Hollenbeck CB, Coulston AM, Quan R, Becker TR, et al. Effects of a commercial starch blocker preparation on carbohydrate digestion and absorption: in vivo and in vitro studies. Am J Clin Nutr 1983;38:498-503.
Layer P, Carlson GL, DiMagno EP (June 1985). “Partially purified white bean amylase inhibitor reduces starch digestion in vitro and inactivates intraduodenal amylase in humans”. Gastroenterology. 88 (6): 1895–902. doi:10.1016/0016-5085(85)90016-2. PMID 2581844
Luzzi R, Belcaro G, Hu S, et al. Beanblock® (standardized dry extract of Phaseolus vulgaris) in mildly overweight subjects: a pilot study. Eur Rev Med Pharmacol Sci. 2014;18(20):3120-3125.
Nchanji EB, Ageyo OC. Do Common Beans (Phaseolus vulgaris L.) Promote Good Health in Humans? A Systematic Review and Meta-Analysis of Clinical and Randomized Controlled Trials. Nutrients. 2021;13(11):3701. Published 2021 Oct 21. doi:10.3390/nu13113701
Onakpoya I, Aldaas S, Terry R, Ernst E. The efficacy of Phaseolus vulgaris as a weight-loss supplement: a systematic review and meta-analysis of randomised clinical trials. Br J Nutr 2011;106:196-202.
Osorio LV, Gamboa JAZ. Random multi-center evaluation to test the efficacy of Phaseolus vulgaris (Precarb) in obese and overweight individuals. 2010. Available at http://www.phase2info.com/wp-content/uploads/downloads/Phase-2-Science%20Dossier_4.2014-web.pdf.
Spadafranca A, Rinelli S, Riva A, et al. Phaseolus vulgaris extract affects glycometabolic and appetite control in healthy human subjects. Br J Nutr 2013;109(10):1789-95.
Udani J, Hardy M, Madsen DC. Blocking carbohydrate absorption and weight loss: A clinical trial using phase 2 brand proprietary fractionated white bean extract. Altern Med Rev 2004;9:63-9.
Udani J, Singh BB. Blocking carbohydrate absorption and weight loss: a clinical trial using a proprietary fractionated white bean extract. Altern Ther Health Med. 2007;13(4):32-37.
Wang S, Chen L, Yang H, Gu J, Wang J, Ren F. Regular intake of white kidney beans extract (Phaseolus vulgaris L.) induces weight loss compared to placebo in obese human subjects [published correction appears in Food Sci Nutr. 2020 Sep 30;8(10):5763]. Food Sci Nutr. 2020;8(3):1315-1324. Published 2020 Feb 5. doi:10.1002/fsn3.1299
Wu X, Xu X, Shen J, Perricone N, Preuss H. Enhanced weight loss from a dietary supplement containing standardized Phaseolus vulgaris extract in overweight men and women. Journal of Applied Research 2010;10:73-79.
Attributions
“Dried Beans” by dominik18s is licensed with CC BY 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/2.0/
“Heinz Beans” by bigoteetoe is licensed with CC BY-NC-SA 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by-nc-sa/2.0/
“red kidney bean curry (rajma)” by Thriving Vegetarian is licensed with CC BY 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/2.0/
See also
- The Benefits of MoringaMoringa may not have significant effects on diabetes or cholesterol. Its most well-researched benefit is likely supporting lactation.
- The Benefits of AshwaghandaAshwagandha is well-known for its benefits in reducing stress and anxiety, with most of the research coming from India and the Middle East.
- The Benefits of SchisandraThe clinical evidence supporting schisandra’s medicinal benefits is too weak. However, it shines as a nutritious functional food.
- Vitamin C for Radiant SkinVitamin C can help reduce wrinkles and protect against UV damage, but there isn’t much proof it works for dark spots or acne.
- Akkermansia Muciniphila for Weight LossAkkermansia Muciniphila may lower obesity risks and improve cardiovascular health, but evidence for weight loss is weak.