|In order to investigate the differences in nutrient intakes and eating habits between people living alone and people living together with family or others by age group, dietary survey data of the subjects aged 20 years or older from 2001 Korean National Health and Nutrition Survey were analyzed. Living status of the subjects was defined as 'single' when the subjects' household member was one person. Age, gender, income, education were adjusted during the comparative analysis. The subjects living alone had diets with lower score of nutritional adequacy ratio and lower quality, and drank more alcoholic beverages when compared with the subjects living together. Females were more greatly affected in dietary intakes by living alone situation than males. Of the four age groups, a group with ages from 30 to 39 years showed less nutrient intake patterns in persons living alone than in persons living together, but the rest three groups with ages from 20 to 29, from 50 to 64, and 65 or older did not show any significant differences. Eating habits of the subjects living alone, such as skipping meals, kinds of snacks, dining-out, were worse as a whole than the other. In conclusion, single living particularly of females or of 30 to 39 years of age group had negative influences on dietary intakes and behavior. There may be statistical errors if socioeconomic and demographic factors such as age, gender, income, and education are not controlled in the population study investigating the effect of living alone on dietary intakes. Further studies will be needed to know the age-specific reasons for the worse nutrient intakes of single living persons.