This study investigated the potential role of dietary factors associated with obesity and metabolic syndrome (MetS) in Koreans. The scoping review method was used to evaluate the studies that utilized the secondary data sets comprising the Korean National Health and Nutrition Examination Survey (KNHANES) and the Korean Genome and Epidemiology Study (KoGES). Articles published between 2012 and 2022 were identified using RISS, KISS, DBpia, PubMed, and ScienceDirect databases. In all, there were 32 published articles on obesity and 119 on MetS. Obesity research included eight articles on nutrients, 12 on food items/food groups, two on dietary patterns, nine on dietary behavior/eating habits, and one on the dietary index. MetS studies comprised 34 articles on nutrients, 43 on food items/food groups, seven on dietary patterns, 25 on dietary behavior/eating habits, and 10 on the dietary index. Carbohydrates, alcohol, and coffee consumption were the most frequently studied dietary factors for obesity and MetS. The primary areas of study were largely focused on nutrients and food items/food groups. Thus, to overcome the paucity of information on the relationship of dietary patterns and dietary indexes with obesity and MetS, there is a need for further research using the KNHANES and KoGES data sets.