The body weight and body mass index ( BMI ) were significantly reduced by week 10 compared with baseline in the yeast group , and these differences were significantly greater than those in the control group : body weight 0.83 kg versus -2.60 k g ( P < 0.001 ) , BMI 0.29 kg/m ( 2 ) versus -0.90 kg/m ( 2 ) ( P < 0.001 ) .