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 1 Characteristics of participants at baseline (n = 9298)

	Participants with a GHQ score ≥ 4		Participants with a GHQ score < 4		P ^a
Categorical variables	n	%	n	%
Number of participants	2601		6697
Area (Shizuoka)	1084	41.7	3578	53.4	< 0.001
Sex (women)	1543	59.3	3227	48.2	< 0.001
Current worker	1996	76.7	4987	74.5	0.023
Smoking					0.002
Never	1623	62.4	3889	58.1
Former	619	23.8	1812	27.1
Current < 20 cigarettes/day	178	6.8	496	7.4
Current 20–39 cigarettes/day	161	6.2	462	6.9
Current ≥40 cigarettes/day	20	0.8	38	0.6
Drinking					0.001
Never	1073	41.3	2720	40.6
Former	49	1.9	82	1.2
Current < 150 g/week	1026	39.4	2500	37.3
Current 150–300 g/week	260	10.0	812	12.1
Current ≥300 g/week	193	7.4	583	8.7
Continuous variables	Mean	SD	Mean	SD
Age (years)	50.1	9.1	52.9	9.5	< 0.001
Sleeping time (h/day)	6.4	0.9	6.6	0.9	< 0.001
Leisure-time exercise (METs • h/day)	1.6	2.6	2.0	2.9	< 0.001
Eating breakfast (times/week)	6.3	1.6	6.5	1.4	< 0.001

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

ISSN: 1475-2891