White Kidney Bean extract and weight loss information, how effective is this supplement, what does the research say

White Kidney Bean extract seems to have some benefit as a natural diet pill but not all studies have shown weight loss benefits.

Blocking carbohydrate absorption and weight loss: a clinical trial using a proprietary fractionated white bean extract.
Altern Ther Health Med. 2007; University of California, Los Angeles School of Medicine, USA.
A proprietary fractionated white bean extract has been shown in vitro to inhibit the digestive enzyme alpha-amylase. This may prevent or delay the digestion of complex carbohydrates, potentially resulting in weight loss. A 4-week randomized, double-blind, placebo-controlled study of 25 healthy subjects consuming 1000 mg of a proprietary fractioned White Kidney Bean extract or an identical placebo twice a day before meals in conjunction with a multi-component weight-loss program, including diet, exercise, and behavioral intervention, was conducted. Both groups reduced their weight and waist size significantly from baseline. The active group lost 6.0 lbs and 2.2 in, and the placebo group lost 4.7 lbs and 2.1. The differences between groups were not significant. Through subsequent exploratory analysis to investigate group findings further, subjects were stratified by total dietary carbohydrate intake. This probative analysis revealed that the tertile of subjects who had consumed the most carbohydrates demonstrated significant reductions in both weight and waist size compared with placebo subjects in the same tertile of carbohydrate intake. Subjects who adhere to a program including dietary modification, exercise, and behavioral intervention can significantly reduce their weight and waist size in a short period of time. In an exploratory analysis of data, the tertile of subjects who ate the most carbohydrates experienced a significant reduction in both weight and waist size with the addition of the White Kidney Bean extract compared to the placebo group of the same tertile of carbohydrate consumption. Longer studies with a larger pool of subjects are required to validate these findings.

A Dietary supplement containing standardized White Kidney Bean extract influences body composition of overweight men and women.
Int J Med Sci. 2007; Cosmetic Research Center, dell'Università Cattolica di Roma, Rome, Italy.
So-called "starch blockers" are listed among natural weight loss supplements. Theoretically, they may promote weight loss by interfering with the breakdown of complex carbohydrates thereby reducing, or at least slowing, the digestive availability of carbohydrate-derived calories and/or by providing resistant starches to the lower gastrointestinal tract. The present research study examines a dietary supplement containing 445 mg of White Kidney Bean extract derived from the white kidney bean, previously shown to inhibit the activity of the digestive enzyme alpha amylase, on body composition of overweight human subjects. A randomized, double-blinded, placebo-controlled study was conducted on 60 pre-selected, slightly overweight volunteers, whose weight had been essentially stable for at least six months. The volunteers were divided into two groups, homogeneous for age, gender, and body weight. The test product containing White Kidney Bean extract and the placebo were taken one tablet per day for 30 consecutive days before a main meal rich in carbohydrates. Each subject's body weight, fat and non-fat mass, skin fold thickness, and waist/hip/thigh circumferences were measured. After 30 days, subjects receiving White Kidney Bean extract with a carbohydrate-rich, 2000- to 2200-calorie diet had significantly greater reduction of body weight, BMI, fat mass, adipose tissue thickness, and waist,/hip/ thigh circumferences while maintaining lean body mass compared to subjects receiving placebo. The results indicate that White Kidney Bean extract produces significant decrements in body weight and suggest decrements in fat mass in the face of maintained lean body mass.

Osteoprotective effect of Phaseolus vulgaris in ovariectomy-induced osteopenia in rats.
Menopause. 2009.
Phytoestrogens and phytoestrogen-containing plants are currently being explored as potential candidates for the treatment of estrogen-related disorders. The aim of this study was to evaluate the anti-osteoporotic effect of the phytoestrogen-rich plant White Kidney Bean extract. Adult Sprague-Dawley rats were either bilaterally ovariectomized (OVX) or sham operated. OVX and sham control groups were administered vehicle, whereas the other two OVX groups were given 0.15 mg/kg estradiol and 1 g/kg methanolic extract of White Kidney Bean seeds orally for 10 weeks (10 rats per group). At autopsy, blood, urine, bones, and uteri of the animals were collected. Serum was evaluated for estradiol, calcium (Ca), phosphorus, alkaline phosphatase, tartarate resistant acid phosphatase, and urine for Ca. The bone density, ash density, mineral content, and mechanical strength of bones was evaluated. Treatment with extract of White Kidney Bean seeds prevented estrogen deficiency-induced osteopenia without affecting the uterine mass. The promising results of the study warrant further investigation of White Kidney Bean extract as a potential candidate for the treatment of postmenopausal osteoporosis.