The purpose of this study was to investigate the effect of medical nutrition therapy (MNT) on anthropometric measurements, quality of diets, and blood parameters through the weight loss program in over weight or obese women. The subjects (n=76, $age;31.1{pm}8.4y,;weight;70.3{pm}7.9kg,;BMI;27.2{pm}2.4kg/m^2$) without medical disease were treated with MNT 5 times for 12 weeks by dietitian. Anthropometric measurements included height, weight, fat mass, lean body mass, triceps and thigh skin-fold thickness, mid-arm, waist, hip and thigh circumference. Dietary assessments were accomplished using 3-days food records, diet quality index (DQI), and dietary pattern. The dietary pattern was assessed by daily energy intakes from breakfast, lunch, dinner, and snacks of calorie density, and numbers of eating. Blood levels of leptin, lipid profiles (total lipids, total cholesterol, LDL-cholesterol, HDL-cholesterol), and insulin were analyzed. Anthropometric measurements decreased significantly after MNT (p<0.001). Waist circumference was reduced most rapidly and tricep skin-fold thickness was reduced most effectively after 12 weeks of MNT. Daily energy intake, calorie density and numbers of eating incidence decreased significantly $0796.4{pm}395.5;vs;1402.9{pm}217.8;kcal/day,;162.3{pm}56.5;vs;113.4{pm}30.1,;5.0{pm}1.4;vs;3.8{pm}0.4$, respectively, p<0.05). The daily energy intake from breakfast and snacks significantly decreased (p<0.001). Calories from snack, calorie density of snack and numbers of snacking also decreased (p<0.05). The mean scores of DQI significantly increased ($7.6{pm}2.1;vs;6.5{pm}1.6$, p<0.05). The plasma levels of total lipid, triglyceride (TG), total cholesterol, LDL-cholesterol and leptin decreased significantly after MNT ($489.8{pm}100.4;vs;447.0{pm}87.3mg/dL,;187.7{pm}34.0;vs;175.9{pm}31.5mg/dL,;115.2{pm}29.2;vs;109.2{pm}26.7mg/dL,;15.7{pm}7.6;vs;12.4{pm}5.9ng/mL$, respectively, p<0.05). These results indicate that MNT efficiently reduced the body weight through the changes in dietary intake, dietary patterns and dietary quality. MNT also changed body composition and reduced the levels of plasma lipid, cholesterol and leptin.