To examine the association between diet quality and osteosarcopenic obesity (OSO), low bone and muscle mass with concurrent high fat mass, in middle-aged and older adults.Data were from a cross-sectional study of 2579 men and 3550 women aged 50 years and older who completed the Korea National Health and Nutritional Examination Survey from 2008 to 2010.Data were collected using 24-h dietary recall, and diet quality was determined by the Diet Quality Index-International (DQI-I), on which higher scores denote better quality. Body composition was evaluated by dual-energy x-ray absorptiometry. The association between dietary quality and the number of body composition abnormalities (including OSO) was analyzed by multinomial logistic regression, adjusting for covariates.In women, after controlling for covariates, higher scores on the DQI-I were associated with a significantly lower number of phenotypes associated with adverse body composition. Those in the highest tertile group of DQI-I were less likely to have OSO compared with those in the lowest tertile (odds ratio=0.54, 95% confidence interval: 0.32-0.92). In men, DQI-I scores were not associated with the number of body composition abnormalities.Middle-aged and older women who eat a healthier diet, as determined by a high DQI-I score, are less likely to have multiple body composition abnormalities.