Table 2. Quality assessment scale score for cohort studies included in the meta-analysis¹.

First author, year of publication (reference)	Representativeness of the exposed cohort	Selection of the unexposed cohort	Ascertainment of exposure	Outcome of interest not present at start of study	Control for important factor or additional factor2	Outcome assessment	Follow-up long enough for outcomes to occur3	Adequacy of follow-up of cohorts4	Data analysis that used an energy-adjusted residual or nutrient-density model	Total quality scores
Arts,2002 [33]	☆	☆	☆	☆	☆☆	☆	☆	-	☆	9
Zamora-Ros,2014 [69]	☆	☆	☆	☆	☆☆	☆	☆	-	☆	9
Touvier,2013 [34]	☆	☆	☆	☆	☆☆	☆	☆	-	☆	9
Wang,2014 a [74]	☆	☆	☆	☆	☆☆	☆	☆	☆	☆	10
Zamora-Ros,2013 a [75]	☆	☆	☆	☆	☆☆	☆	☆	-	☆	9
Mursu,2008 [77]	☆	☆	-	☆	☆☆	☆	☆	☆	☆	9
Nimptsch,2016 [44]	-	☆	☆	☆	☆☆	☆	☆	☆	-	8
Simons,2009 [35]	-	☆	☆	☆	☆☆	☆	☆	☆	-	8
Vermeulen,2013 [84]	☆	☆	☆	☆	☆☆	☆	☆	-	☆	9
Zamora-Ros,2012 [88]	☆	☆	☆	☆	☆☆	☆	☆	-	☆	9
Zamora-Ros,2013 c [92]	☆	☆	☆	☆	☆☆	☆	☆	-	☆	9
Arts,2001 [36]	☆	☆	☆	☆	☆☆	☆	☆	☆	☆	10
Cutler,2008 [94]	☆	☆	☆	☆	☆☆	-	☆	☆	☆	9
Arem,2013 [97]	☆	☆	☆	☆	☆☆	☆	☆	-	☆	9
Bobe,2008 [39]	-	☆	☆	☆	☆☆	☆	☆	-	☆	8
Geybels,2013 [38]	-	☆	☆	☆	☆☆	☆	☆	☆	☆	9
Wang,2014 b [100]	☆	☆	☆	☆	☆☆	☆	-	-	☆	8
Xiao,2014 [102]	☆	☆	☆	☆	☆☆	☆	☆	-	☆	9

¹A study could be awarded a maximum of one star for each item, while two stars for the item Control for important factor or additional factor.

²A maximum of two stars could be awarded for this item. Studies similar to others in terms of patient characteristics (age, sex, BMI) received one star, whereas studies that controlled for other important confounders such as smoking and drinking received an additional star.

³A cohort study with a follow-up time >8 y was awarded one star.

⁴A cohort study with a follow-up rate >75% was awarded one star.