According to ScienceDaily, UCLA researchers reported that an extract in white kidney beans may stop carbohydrates from breaking down into sugars. Normally, a digestive enzyme in the body metabolizes starches into little pieces of sugars. White kidney bean extract is suggested to stop this process so the starches remain in the form of fibers. Fibers cannot be absorbed and therefore do not become body fat.
According to the HealthGuidance website, some people suffer from various minor side effects and discomforts such bloating, gas, nausea, vomiting and diarrhea. Usually the gastrointestinal symptoms are short-lived and mild. Also, white kidney bean extract may lower blood sugar, and therefore close monitoring of blood sugar is important for patients with diabetes or those who have just undergone surgeries. Not enough is known about the use of white kidney bean extract during pregnancy and breastfeeding, so it is recommended to avoid use during these times.