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Kidney Bean Powder

Also known as: Kidney bean powder, White kidney bean extract, Phaseolus vulgaris L.

Overview

Kidney bean powder, derived from the common bean Phaseolus vulgaris, particularly white kidney beans, is a dietary supplement primarily used as a starch blocker and weight management aid. It contains α-amylase inhibitors, which reduce the digestion and absorption of dietary starch, leading to a decrease in caloric intake. This mechanism can also help modulate blood glucose levels. The supplement is available in various forms, including capsules and powders, and is often marketed for its potential to promote weight loss and improve body composition. Research on kidney bean powder is moderately mature, with several randomized controlled trials and meta-analyses available, although some studies have methodological limitations. It is generally considered safe for most adults, with mild gastrointestinal side effects being the most commonly reported adverse effects. Optimal dosing typically ranges from 1,000 to 3,000 mg daily, taken before meals containing starch.

Benefits

White kidney bean extract has demonstrated potential benefits in weight management and glycemic control. It promotes modest weight loss by inhibiting starch digestion, leading to reduced calorie absorption. A recent RCT demonstrated statistically significant greater weight loss compared to placebo when supplemented with white kidney bean extract. Some evidence suggests improvements in body fat percentage and waist circumference, though effect sizes vary. The extract may also modulate blood glucose levels by altering gut microbiota composition, which is linked to improved metabolism and glucose regulation. Overweight and obese adults appear to benefit most from supplementation. Meta-analyses report small to moderate effects on weight loss, but some individual trials have methodological flaws limiting confidence. Benefits typically emerge over weeks to months of supplementation.

How it works

Kidney bean powder primarily works by inhibiting the α-amylase enzyme, which is responsible for breaking down dietary starch into glucose. By inhibiting this enzyme, the digestion and absorption of starch are reduced, leading to a decrease in caloric intake. This process also results in decreased postprandial blood glucose spikes. Additionally, the extract may modulate gut microbiota, contributing to metabolic improvements. The extract's effects are primarily localized in the gastrointestinal tract, as it is minimally absorbed into the bloodstream.

Side effects

Kidney bean powder is generally considered safe, with few reported adverse effects. The most common side effects are mild gastrointestinal symptoms such as bloating, gas, or diarrhea. No serious adverse events have been reported in high-quality trials. However, caution is advised when combined with antidiabetic medications due to potential additive effects, which could lead to hypoglycemia. It is contraindicated for individuals with legume allergies. Safety in pregnancy, lactation, and children is not well established, and use in these populations should be avoided. Individuals should start with a low dose to assess tolerance and gradually increase as needed. If severe gastrointestinal symptoms occur, discontinue use.

Dosage

The recommended dosage of white kidney bean extract typically ranges from 1,000 mg to 3,000 mg per day, divided into multiple doses taken before meals. Studies often use doses ranging from 500 mg to 3,000 mg daily. It is best taken shortly before carbohydrate-rich meals to maximize its starch-blocking effects. Standardized extracts with verified α-amylase inhibitory activity are preferred. While there is no established upper limit, doses above 3,000 mg have not shown additional benefits and may increase gastrointestinal side effects. Effectiveness depends on timing relative to meals and carbohydrate content. No specific cofactors are required for its activity.

FAQs

Is kidney bean powder effective for weight loss?

Evidence supports modest weight loss benefits when combined with diet and exercise.

Are there any safety concerns?

It is generally safe with minor gastrointestinal side effects like bloating and gas.

When should it be taken?

Take it before meals containing starch for optimal starch-blocking effect.

How soon will results appear?

Typically, noticeable effects appear within weeks to a few months of consistent use.

Does it block all carbohydrates?

It primarily inhibits starch digestion; sugars are generally unaffected by this supplement.

Research Sources

https://examine.com/research-feed/study/9kjMw0/ – A randomized controlled trial found that white kidney bean extract led to statistically significant weight loss compared to a placebo group in overweight adults. The study was limited by its sample size and short duration, but it was well-controlled, indicating moderate quality evidence supporting the supplement's efficacy for weight loss.
https://www.crd.york.ac.uk/PROSPERO/view/CRD42022355744 – A systematic review and meta-analysis of multiple RCTs, totaling over 300 participants, found small to moderate weight loss effects associated with kidney bean extract. The review noted heterogeneity and methodological flaws in some of the included trials, suggesting a need for more rigorous studies to confirm these findings.
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0007114511001516 – A meta-analysis of 6 RCTs showed non-significant weight loss effects overall, highlighting methodological flaws in the included studies. The review indicated that the small number of high-quality trials and inconsistent results contributed to the low to moderate quality of the evidence, suggesting that early evidence was inconclusive.
https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2021.664976/full – This research explores the impact of white kidney bean extract on gut microbiota composition and its potential link to improved metabolism and glucose regulation. The study suggests that the extract's modulation of gut microbiota may contribute to its beneficial effects on glycemic control, providing insights into the underlying mechanisms of action.
https://www.verywellfit.com/white-bean-extract-90059 – This article provides a general overview of white bean extract, discussing its potential benefits for weight loss and blood sugar control. It highlights the mechanism of action, dosage recommendations, and potential side effects, offering a comprehensive summary for consumers interested in using the supplement.