The principal objective of this study was to assess the effects of low-calorie diets(LCD) for 8 weeks of medical nutrition therapy in individuals with BMI in excess of $23;kg/m^2$. 41 over-weight or obese individuals (male=14, female=27, age $28.6{pm}8.9;yrs$), none of whom were diagnosed with a medical disease, were administered MNT 4 times over the study period. Approximately $1,100{sim}1,300;kcal/day$ were prescribed by a dietitian, via individualized counseling. Anthropometric parameters, daily nutrient intake, and blood levels of leptin, insulin, and lipid profiles were measured prior to and after the 8 weeks of the intervention period. We noted significant reductions in body weight, body mass index (BMI), fat mass (FM), visceral adipose tissue (VAT), abdominal skin-fold thickness, and waist circumference in both men and women. The mean body weight losses in men and women were $3.2{pm}0.6;kg$/8 weeks and $2.8{pm}0.6;kg$/8 weeks, respectively. However, the % of lean body mass (LBM) in men and women was shown to increase significantly (p<0.05). The daily intake of calorie, fat, protein, vitamin E, folate, and iron were significantly reduced during the LCD period. Blood levels of lipids and glucose were in normal range, and evidenced no changes after LCD. However, the serum levels of leptin in female subjects were significantly reduced (p<0.00l) from $8.9{pm}4.8;ng/mL$ to $6.9{pm}4.8;ng/mL$. In conclusion, 8 weeks of LCD with individualized counseling by a dietitian effectively reduced body fat and visceral fat in both men and women with BMI in excess of $23;kg/m^2$.