OBJECTIVES: Food price is a determining factor in food choice which affect diet quality accordingly. However, the association between food price and diet quality has not been thoroughly discussed among Chinese adults. This study aimed to analyze the association of daily energy-adjusted dietary costs (CNY/2000 kcal) and diet quality among Chinese adults. METHODS: A total of 680 Chinese adults aged above 25 years from Henan province were investigated in 2020. Three indices were adopted for evaluating diet quality: the nutrient-rich foods 9.2 (NRF 9.2) index for evaluating nutrient density, the mean adequacy ratio (MAR) for evaluating nutrient adequacy, energy density (ED) based on solid foods only for evaluating energy density. The daily energy-adjusted diet cost was calculated by dividing the estimated daily diet costs (CNY/day) by the energy intake per day (kcal/day) and multiplying the result by 2000. RESULTS: Subjects who closely adhered to the NRF9.2, MAR, and ED paid ¥8.92, ¥13.17, and ¥14.34 more for daily food consumption, respectively, than those who weakly adhered to these dietary patterns did. Furthermore, multiple linear regression analysis adjusted covariance revealed that an increase in ¥1 of the energy-adjusted diet cost per day was associated with changes of 0.494 units (P <
0.001), 0.003 units (P <
0.001), and - 0.018 units (P <
0.001) in the NRF9.2, MAR, and ED, respectively. CONCLUSION: Higher energy-adjusted diet cost was associated with higher quality diets. This might be important for public health policies to develop strategies to promote healthy diets by regulating food supply and its costs.