It is generally accepted that diet modification provides beneficial effects on the management of diabetes. In the present study, we evaluated the effects of diet modification on nutrient intake and quality of life in a large sample of diabetic patients. This study was conducted using data from the Korea National Health and Nutrition Examination Survey IV and V (2007-2010). A total of 2,484 of diabetic patients were included in the analysis. Then, we compared the overall quality of dietary intake between diabetic patients with diet modification and those without dietary modification. The result showed that subjects on diabetic diet (DDG) showed lower levels of total cholesterol, triglyceride, and AST before and after the adjustment for covariates (all p < 0.05). The results of nutrient assessment showed that DDG had lower intakes of total energy, fat, and carbohydrate (all p < 0.05), but higher intakes of energy from protein, vitamin B1, vitamin B2, niacin and vitamin C than NDG. (all p < 0.05). In addition, nutritional adequacy ratio of calcium and vitamin B2 were significantly higher in DDG than those in normal diet group (NDG) (p < 0.05). However, we observed no significant differences in quality of life between two groups. In conclusion, diet modification in diabetic patients seemed to be effective to improve blood lipid profile and the adequacy of nutrient intake without sacrificing the quality of life.