White kidney bean is a variety of the common bean (Phaseolus vulgaris), which contains a protein (α-amylase blocker) that purportedly blocks the breakdown and digestion of starch
In humans, this protein has been claimed to:
Act as a carbohydrate absorption blocker
Help burn fat reserves
Suppress appetite
Reduce blood sugar and insulin spikes after meals
Additionally, white kidney beans contain the lectin phytohemagglutinin. While high amounts of phytohemagglutinin are toxic to humans, lower concentrations can have appetite-suppressing effects
For these reasons, white kidney bean extract is sold under different brands as a weight loss supplement. The main white kidney bean extract supplements are :
Phase 2 (also known as Phaseolamin 2250, Phase 2 Starch Neutralizer, and Starch Lite), an α-amylase blocker
Beanblock, a combination of an α-amylase blocker and phytohemagglutinin