Table 2. Average weekly consumption frequencies of foods and dishes in the FFQ of 2013–2016 KNHANES based on self-reported chewing ability of male subjects.

Food groups	Food items	Serving size	NDC (n = 6,699)	DC (n = 2,193)
Grains	Steamed sweet potatoes·grilled sweet potatoes	1 sweet potato	0.32 ± 0.02	0.26 ± 0.02**
	Loaf bread	2 slices	0.24 ± 0.02	0.18 ± 0.03**
	Steamed potatoes·grilled potatoes	1 potato	0.14 ± 0.01	0.12 ± 0.01*
	Ready-to-eat cereal	1 soup bowl	0.12 ± 0.02	0.07 ± 0.02*
Meats·fish·eggs·beans	Squid (raw, dried shredded, boiled, stir-fried)·dried squid	1/4 of a squid	0.39 ± 0.03	0.31 ± 0.03*
	Stir-fried beef	1 cup	0.17 ± 0.02	0.14 ± 0.02*
Vegetables	Other kimchi·fresh vegetable kimchi	1/4 cup	4.42 ± 0.19	4.02 ± 0.22*
	Stir-fried lotus roots·stir-fried burdock	1/4 cup	0.30 ± 0.02	0.24 ± 0.03*
	Green laver salad·brown seaweed salad	1/4 cup	0.26 ± 0.02	0.21 ± 0.02**
Fruits	Apple	1 apple	1.48 ± 0.06	1.13 ± 0.07****
	Tomato·cherry tomato	1 tomato	0.82 ± 0.05	0.69 ± 0.05**
	Orange	1 orange	0.21 ± 0.02	0.16 ± 0.03*
	Kiwi	2 kiwis	0.09 ± 0.01	0.06 ± 0.01**
Milk·dairy products	Curd type yogurt	1 serving	0.46 ± 0.04	0.34 ± 0.05*
Beverages	Green tea	1 cup	1.16 ± 0.14	0.87 ± 0.14**
Dishes	Sweet and sour pork·pork cutlet	1 cup	0.19 ± 0.02	0.16 ± 0.02*
	Tteokbokki	1 cup	0.13 ± 0.02	0.08 ± 0.02***

Mean ± SE for weekly consumption frequencies of FFQ items.

FFQ, food frequency questionnaire; KNHANES, Korea National Health and Nutrition Examination Survey; NDC, not difficult in chewing; DC, difficult in chewing.

^*P < 0.05, ^**P < 0.01, ^***P < 0.001, ^****P < 0.0001 by one-sided survey regression test after adjusted for age, household income, and self-rated health status.