AbstractThe Developmental Origins of Health and Disease (DOHaD) approach supports that nutritional exposures in early life affect an individual’s later health and risk of disease. Dietary exposure during the preconception period may also influence individual, and inter- and transgenerational health and disease risk, in both men and women. This study aimed to describe knowledge of the DOHaD approach (DOHaD_KNOWLEDGE) and diet quality in preconception young adults in Norway, to assess associations between DOHaD_KNOWLEDGE and a Diet Quality Score (DQS), and to assess gender differences in those above. Data from 1362 preconception young adults was obtained from the PREPARED study baseline dataset. The sample had 88% women participants, a mean age of 27 years, 36% had overweight or obesity, and 77% had higher level of education. DOHaD_KNOWLEDGE was assessed by the participants’ agreement to five statements using a Likert scale. Diet quality was assessed using aspects of diet quality and a DQS derived from a dietary screener. We found moderate level of both DOHaD_KNOWLEDGE (12/20 points) and diet quality (DQS: 60/100 points), indicating potential for improvements. Specifically, the greatest potential for diet quality improvements were observed for sugary foods, red and processed meats, legumes, and unsalted nuts and seeds. Gender differences were observed for both DOHaD_KNOWLEDGE and diet quality. DOHaD_KNOWLEDGE was positively associated with DQS, adjusted for sociodemographic factors, with little evidence of an interaction effect by gender. This study indicates that knowledge of the DOHaD approach is positively associated with diet quality in preconception young men and women. Future studies should consider incorporating pregnancy intentions, relationship status, and health literacy.