Summary This study examined the relationship between the subjective food intake of 30 food types and their objective bite force to identify the key food items within the 30 food types to achieve a greater depth of masticatory function in Korean adults. A sample of 308 (112 males and 196 females) adults over the age of 20 (average age, 48·6) was selected among patients who visited four dental hospitals in Seoul, Korea. The subjective masticatory ability was evaluated through an interview with food intake ability questionnaires consisting of 30 food types ranging from hard to soft using a five-step Likert scale. The objective maximal bite force was measured using pressure-sensitive films. The relationship between the food intake ability and bite force was analysed and stratified according to age, gender, number of post-canine teeth lost and several clinical oral health indicators. The key foods were selected using correlation and factor analysis. The subjective food intake ability between the 30 foods and key foods were tested by cluster and one-way anova analysis. The Pearson’s correlation coefficient between food intake ability and bite force was 0·45 (P < 0·01). The five key food items selected were dried cuttlefish, raw carrot, dried peanut, cubed white radish kimchi and caramel. The correlation coefficient between the food intake ability and bite force of these items was 0·51 (P < 0·01). These results suggest that the subjective food intake ability using the 30 and five key foods can be used to evaluate the masticatory function in Korean adults.