This study aimed to investigate whether dietary quantity and/or quality differ according to food security levels in the Korean adult population. Dietary adequacy and quality were evaluated by the Korean Dietary Reference Intake and the Korean Healthy Eating Index (KHEI) for adults, respectively, according to three food security levels, i.e., food security, low food security, and very low food security. A total of 7144 Korean adults (aged 19 to 64 years) were selected from cross-sectional data from the 2013-2015 Korean National Health and Nutrition Examination Surveys. The risk of inadequate nutrient intakes of protein (p trend = 0.021) and phosphorus (p trend = 0.002) increased according to food insecurity levels after adjustment for putative risk factors. The total KHEI scores (p < 0.001) as well as scores of having breakfast (p < 0.001) were lowest in the very low food security group. Among KHEI components, adults with food insecurity were less likely to get full scores from intakes of mixed grains (p trend = 0.016), total fruit (p trend = 0.039), fresh fruit (p trend = 0.043), and breakfast (p trend < 0.001). In addition, food-insecure adults were more likely to get zero score from intakes of fresh fruit (p trend = 0.020), milk and dairy products (p trend = 0.049), breakfast (p trend < 0.001), % of energy from sweets and beverages (p trend = 0.002), and total energy (p trend = 0.033). In conclusion, food security levels were associated with how much they ate, as well what they ate, in adults in South Korea. These results implied that the diet adequacy as well as moderation and balance could be carefully treated with food assistance or nutrition intervention once nutritional adequacy has mostly been met. In addition, targeted intervention programs tailored to diverse contexts for improving food insecurity may prevent unintended consequences due to easy access to inexpensive obesogenic foods in adults with food insecurity.
Keywords: adults; dietary adequacy; dietary quality; food insecurity; healthy eating index.