The mean concentration of leptin was significantly decreased in all groups after the dietary intervention , but the mean changes in leptin level in the PLCD group was more prominent compared to the other two groups ( -2.38 , p < 0.001 [ PLCD ] vs -1.75 , p = 0.002 [ RLCD ] and -0.55 ng/mL , p = 0.12 [ PWLCD ] ) .