Associations between diet and mental health using the 12-item General Health Questionnaire: cross-sectional and prospective analyses from the Japan Multi-Institutional Collaborative Cohort Study

Table 2 Participants’ (baseline) characteristics at follow-up (n = 4701)

	Participants with a GHQ score ≥4		Participants with a GHQ score <4		P ^a
Categorical variables	n	%	n	%
Number of participants	783		3918
Area (Shizuoka)	433	55.3	2173	55.5	0.934
Sex (women)	432	55.2	1805	46.1	< 0.001
Current worker	609	77.8	2918	74.5	0.051
Smoking					0.047
Never	496	63.3	2285	58.3
Former	186	23.8	1123	28.7
Current < 20 cigarettes/day	47	6.0	266	6.8
Current 20–39 cigarettes/day	50	6.4	229	5.8
Current ≥40 cigarettes/day	4	0.5	15	0.4
Drinking					0.21
Never	349	44.6	1575	40.2
Former	9	1.1	42	1.1
Current < 150 g/week	283	36.1	1498	38.2
Current 150–300 g/week	87	11.1	475	12.1
Current ≥300 g/week	55	7.0	328	8.4
Continuous variables	Mean	SD	Mean	SD
Age (years)	50.2	9.1	54.0	9.1	< 0.001
Sleeping time (h/day)	6.5	0.9	6.7	0.9	< 0.001
Leisure-time exercise (METs ▪ h/day)	1.8	2.5	2.2	3.0	< 0.001
Eating breakfast (times/week)	6.5	1.3	6.6	1.3	0.168

GHQ General Health Questionnaire, METs Metabolic equivalents, SD Standard deviation
^aCategorical variables: χ² test; continuous variables: t-test

ISSN: 1475-2891