Pure White Kidney Bean Extract This can be Mother Nature’s answer to weight loss. 3 studies incontestable important loss of weight with Phase two compared to a placebo management in those who are overweight or corpulent. The doses ranged from four5 mg for 4 weeks to 3000 mg for eight to twelve weeks. A placebo controlled study by showed a comparative loss in weight only if subjects were stratified by dietary saccharide intake.