Table 5.

Characteristics of studies identified by systematic review and included in the meta-analysis

Author	Country/ countries	Age (yrs)/ sex/ years of follow-up	Exposure assessment	Highest intake category/ reference category *	Number of diabetes cases/ assessment of type 2 diabetes/ assessment criteria (if stated)	Exclusion criteria	Variables adjusted for in analyses †
Current results from EPIC- InterAct study	France, Germany, The Netherlands, UK, Italy, Sweden, Denmark, and Spain	40-79/ men & women/ 11	Country specific dietary questionnaires	FV: 8.71/2.13 Fruit: 5.39/0.75 Veg: 3.94/0.88 GLV: 5.93/0.05 RV: 3.87/0.12	10 821/ Self-report (self-report of doctor diagnosed diabetes, anti- diabetic drug use), linkage to primary and secondary care registers, medication use (drug registers), hospital admissions and mortality data with a coding for diabetes, local and national diabetes and pharmaceutical registers	Incomplete dietary information; extreme values for total energy intake (top or bottom 1% of the original EPIC study sample); missing information on potential confounding variables; diabetes, myocardial infarction or stroke at baseline.	Age, sex, centre, country, education level, BMI, physical activity level, smoking status, total energy intake, alcohol intake
Villegas et al, 2008 30	China (Shanghai Women’s Health Study)	40-70/ women/ 4.6	77 item food frequency questionnaire. Mean of intake between baseline and follow- up used.	Fruit: 5.57/1.09 Veg: 5.35/1.52 GLV: 11.91/2.45 RV: 1.51/0.04	1 608/ Self-report (self-report of doctor diagnosed diabetes, glucose test history and/or use of hypoglycaemic medication)/ ADA 1997 criteria	<40 yrs or > 70 yrs; type 2 diabetes, cancer, or cardiovascular disease present at baseline; extreme values for total energy intake (<2,090 or >14,630 KJ/d).	Age, EI, meat intake, BMI, WHR, smoking, alcohol, PA, income level, education level, occupational status, hypertension
Bazzano et al, 2008 7	USA (Nurses’ Health Study)	30-55/ women/ 18	61 item food frequency questionnaire	F&V: 7.66/2.35 Fruit: 2.64/0.46 Veg: 5.40/1.61 GLV: 10.36/1.75	4 529/ Self-report with questionnaire (asking about symptoms, diagnostic tests, and treatments) / NDDG criteria before 1997, ADA criteria after 1997	Extreme values for total energy intake (<600 or >3,500 Kcal/d); ≥12 FFQ items left blank; diabetes or missing data for diabetes, cancer, or cardiovascular disease present at baseline; missing date for diabetes at follow-up	Age, BMI, PA, family history of diabetes, postmenopausal hormone use, alcohol use, smoking, EI
Montonen et al, 2005 29	Finland (Finnish Mobile Clinic Health Examination Survey)	40-69/ men & women/ 23	Diet history interview	Fruit: 2.17/0.0 Veg: 1.94/0.30 GLV: 4.55/0.39	383/ Social Insurance Institution nationwide register of persons receiving drug reimbursement (for diabetes)	<40 yrs or > 69 yrs; extreme values for total energy intake (<800 or >6,000 Kcal/d); pregnant women; diabetes at baseline.	Age, sex, BMI, EI, smoking, family history of diabetes, geographic area
Liu et al, 2004 10	USA (Women’s Health Study)	≥45/ women/ 8.8	131 item food frequency questionnaire	F&V: 10.16/2.54 Fruit: 3.91/0.62 Veg: 6.84/1.47 GLV: 9.94/0.98 RV: 7.00/0.49	1 614/ Self-report of doctor diagnosed diabetes (with confirmation from different sources including: bloods, telephone interview, supplementary questionnaire, contact with doctor)	Diabetes present at baseline	Age, smoking, EI, alcohol use, BMI, PA, history of hypertension, history of high cholesterol, family history of diabetes
Ford and Mokdad, 2001 8	USA (NHANES I)	25-74/ men & women/ 20	24-hour recall	F&V: ≥6.5/0.0	1 018/ Self-report of doctor diagnosed diabetes, hospitalisation record ICD-9-CM: 250, death certificate ICD-9: 250	Not white or African American; insufficient information of diabetes status; prevalent diabetes; pregnant women; and those with missing data for covariates	Age, sex, smoking status, systolic BP, cholesterol concentration, antihypertensive medication, recreational exercise, non-recreational activity, alcohol use, BMI, education
Meyer et al, 2000 11	USA (Iowa Women’s Health Study)	55-69/ women/ 6	127 item food frequency questionnaire	F&V: 8.86/2.57 Fruit: 3.36/0.57 Veg: 5.93/1.57	1 141/ Self-report (self-report of doctor diagnosed diabetes, anti- diabetic drug use)	Extreme values for total energy intake (<2,510 or >20,920 KJ/d); ≥30 FFQ items left blank; diabetes at baseline	Age, EI, BMI, WHR, education, smoking, alcohol intake, PA

^*Veg=vegetables; GLV=green leafy vegetables; RV=root vegetables; F&V, fruit and vegetables are in portions/d; GLV and RV are in portions/week.

^†BMI=body mass index; EI=energy intake; WHR=waist-to-hip ratio; PA=physical activity; BP=blood pressure.

Note: Harding et al. paper not included in systematic review as those data are included within EPIC-InterAct.