Table 1.

General characteristics of subject by dinner companion (n=14,093)

Characteristic		Eating alone	Eating together		P-value
			With family	With non-family
No. of subjects		3,223	9,280	1,590
Age (y)		56.56±17.09	52.08±15.94	42.28±14.95	<0.001
Male		35.09	60.06	40.30	<0.001
Body mass index (kg/m2)		23.97±3.56	23.80±3.47	24.13±3.57
Household income					<0.001
	Lower half	57.69	42.16	27.88
	Upper half	42.31	57.84	72.12
Education level					<0.001
	Middle school (grade 6–9) or lower	44.71	28.98	12.96
	High school (grade 10–12)	23.66	28.16	23.98
	College or higher	31.64	42.86	63.06
Alcohol					<0.001
	Moderate drinking	86.97	85.51	71.89
	Problem drinking	13.03	14.49	28.11
Smoking					<0.001
	Never	67.66	65.11	51.17
	Ex	16.00	20.42	18.28
	Current	16.34	14.46	30.55
Aerobic exercise					<0.001
	Yes	44.37	44.93	50.94
	No	55.63	55.07	49.06
Eating out frequency					<0.001
	Rare (≤3 times/mo)	35.56	29.89	5.60
	Usually (1–4 times/wk)	35.15	38.08	14.47
	Often (≥5 times/wk)	29.29	32.03	79.94
Living alone (%)					<0.001
	Yes	39.50	1.25	16.73
	No	60.50	98.75	83.27
Depression*		26.62	17.67	18.36	<0.001
Suicidal ideation†		10.98	5.24	4.65	<0.001

Values are presented as mean±standard deviation or %, unless otherwise stated. P-values by chi-square test or t-test. Eating alone: do not have accompanied family members and non-family members at dinner for the past year; household income: monthly income of the householder of the year is divided into two categories; moderate drinking: non-problem drinking; problem drinking: drink more than twice a week and the average alcohol consumption is 7 drinks or more for men and 5 drinks or more for women; never smokers: less than five packs of cigarettes in their lifetime; ex-smokers: smoked in the past but did not currently smoke; aerobic exercise: and physical activity was performed over 2 hours and 30 minutes per week, or for more than 1 hour and 15 minutes at a high-intensity level.

PHQ, Patient Health Questionnaire.

^*PHQ-9 ≥5.

^†PHQ-9 9th question.