TABLE 1.

Risk of bias assessment of cohort studies (0–2 points)¹

Subitems	Low risk of bias (two-thirds or more of included studies) = 0.5 points for each subitem	High risk of bias (over one-third of included studies) = 0 points for each subitem	Unclear risk of bias = 0.25 points for each subitem
Ascertainment of exposure	E.g., validated, calibrated FFQ or 24-h recall, diet history, or diet records (multiple days);	E.g., unvalidated FFQ, single 24-h recall, diet records, or diet history;	Assessed, but unclear2
	Diet-associated biomarkers, e.g., 24-h urine	Diet associated biomarkers: morning urine;
		Or not assessed
Adjusted basic model and outcome-relevant adjustments	Basic model: ≥2 factors—sex, age, education, ethnicity; if only one sex included, then ≥1 factor;	Basic model: <2 factors—sex, age, education, ethnicity; if only one sex included, then ≤1 factor;	Assessed, but unclear2
	Outcome relevant adjustments: ≥3 factors—alcohol, energy intake, smoking, physical activity, BMI, CVD risk factors (blood pressure, dyslipidemia, family history of CVD)	Outcome-relevant adjustments: <3 factors—alcohol, energy intake, smoking, physical activity, BMI, CVD risk factors (blood pressure, dyslipidemia, family history of CVD);
		Or not assessed
Assessment of outcome	E.g., record linkage (ICD codes), accepted clinical criteria, independent or blind assessment	E.g., self-report (not validated);	Assessed, but unclear2
		Or not assessed
Adequacy of follow-up duration	E.g., median ≥10 y for CVD, median ≥5 y for T2DM	E.g., median <10 y for CVD, median <5 y for T2DM;	Assessed, but unclear2
		Or not assessed

¹CVD, cardiovascular disease; ICD, International Classification of Diseases; T2DM, type 2 diabetes mellitus.

²E.g., when too few details are available to make a judgment for low or high risk of bias.