Table 3.

Pooled risks of type 2 diabetes mellitus (T2DM; and 95 % confidence intervals) in association ‘unhealthy’ dietary patterns in different subgroup analyses

				Meta-analysis		Heterogeneity
Subgroup	Category	No. of studies	No. of participants	OR	95 % CI	I 2 (%)	P value	P value for between-subgroup heterogenity
Sex	Female	2	76 145	1·01	0·68, 1·51	84·3	0·01	0·02
	Male	3	106 576	1·39	1·19, 1·62	53·1	0·11
	Both	7	179 217	1·35	1·18, 1·53	52·5	0·05
Region	Western	8	254 057	1·38	1·26, 1·52	51·9	0·04	0·004
	Eastern	4	107 881	1·07	0·86, 1·33	61·6	0·05
Overall quality score of study	High	5	159 107	1·40	1·26, 1·56	33·5	0·19	0·03
	Low	7	202 831	1·21	1·04, 1·41	70·2	0·003
Follow-up years	≥10 years	8	255 435	1·39	1·26, 1·52	40·7	0·11	0·001
	<10 years	4	106 503	1·12	0·92, 1·38	63·7	0·04
Person-years	≥100 000	3	116 362	1·53	1·36, 1·71	0·0	0·87	0·003
	<100 000	4	68 572	1·25	1·06, 1·48	54·0	0·09
Adjustment for physical activity	Yes	10	320 847	1·27	1·15, 1·42	68·4	0·001	0·17
	No	2	41 091	1·53	1·20, 1·97	0·0	0·72
Publication year	After 2010	7	202 831	1·21	1·05, 1·40	66·6	0·006	0·22
	Before 2010	5	159 107	1·42	1·22, 1·66	63·9	0·03
Adjustment for family history of T2DM	Yes	6	217 854	1·32	1·08, 1·61	74·0	0·002	0·20
	No	6	144 084	1·27	1·15, 1·41	47·9	0·09
Ethnic difference	Western	5	173 534	1·54	1·39, 1·70	0·0	0·98	<0·001
	Western-Japanese/Chinese	3	80 523	1·26	1·14, 1·40	50·3	0·13
	Japanese/Chinese	4	107 881	1·07	0·86, 1·33	61·6	0·05
Adjustment for educational status	Yes	3	95 897	1·35	1·19, 1·53	42·6	0·17	0·36
	No	9	266 041	1·27	1·11, 1·46	69·4	0·001
T2DM incidence	≥1000 cases	6	230 746	1·36	1·22, 1·51	52·7	0·06	0·03
	<1000 cases	6	131 192	1·24	1·04, 1·48	67·1	0·009
Health-care system employee participants	Yes	5	213 550	1·29	1·02, 1·63	78·8	0·001	0·34
	No	7	18 388	1·29	1·17, 1·42	44·1	0·09