Objectives: Patients with metabolic syndrome will be assessed to determine the effects of low carbohydrate diets on serum concentrations of inflammatory and metabolic factors, weight and body composition. Design: A randomized controlled trial with factorial design. Setting and conduct: 80 Subjects will be randomly divided into four groups. For each patient anthropometric measurement, general characteristics will be assessed and 15 cc fasting blood samples will be taken from each patient at the baseline and end of study. 24-h food record questionnaire and physical activity questionnaire will be completed every four week. Inclusion criteria: Age: 20-50 years old; meeting the NCEP-ATPIII criteria (Three or more of the following five criteria should be met: Waist circumference over 40 inches (men) or 35 inches (women); Blood pressure over 130/85 mmHg; Fasting triglyceride over 150 mg/dl; Fasting HDL-cholesterol less than 40 mg/dl (men) or 50 mg/dl (women) and fasting blood sugar over 100 mg/dl). Exclusion criteria: Alcohol and tobacco consumption; Pregnancy; Lactation, Menopause; History of acute or chronic liver failure; Gastrointestinal diseases; Cholestasis; Diabetes, Kidney disease, Seizure, Autoimmune diseases, Thyroid disorders; Using estrogen, Hormone replacement therapy; Routine consumption of oral contraceptives, Insulin therapy; Malignancy; Routine consumption of antioxidants and vitamin/mineral supplements; Following vegetarian diet or any other special diet in the last 3 months. Intervention: Subjects will randomly receive either type of low carbohydrate diets for 12 weeks. Main outcome measures (variables): Weight changes, Body composition, Serum CTRP1, FGF-21, Chemerin, Asprosin, plasma levels of EMPs, Appetite regulatory hormones before and after the intervention.