This study aimed to compare energy nutrient intake, health related factors, physical characteristics, blood biochemical indices, prevalence of metabolic syndrome and odds ratio (OR) of metabolic syndrome based on dietary fat energy ratio. Subjects were 1,205 men aged 40~64 years. The average fat intake was 52.8 g. Subjects were divided into three groups (deficient, normal, excess) based on dietary fat energy ratio. The dietary fat energy rations of the three groups were 36.9%, 42.9% and 20.2%, respectively. Energy and protein intake were increased significantly with dietary fat energy ratio (p<0.001), whereas carbohydrate intake decreased (p<0.001). In health related factors, amount of smoking alone showed increase based on dietary fat energy ratio (p<0.001). In comparing physical characteristics, blood pressure and blood biochemical indices, excepting diastolic blood pressure, increased significantly based on dietary fat energy ratio (p<0.01~p<0.001). The rate that exceeded criteria in risk factors for metabolic syndrome was higher in the serum triglyceride (41.2%) and was lower in the waist circumference (22.2%). Prevalence of metabolic syndrome was 37.9%, and showed significant correlation to dietary fat energy ratio (p<0.05). The OR of metabolic syndrome was higher in deficient and excess group than in normal group, but it had no relationship between fat energy ratio and metabolic syndrome. The results of this study provide basic data to establish fat intake guidelines for prevention of metabolic syndrome in middle-aged men.