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Table 2 Risk of bias in included studies

From: Systematic review and meta-analysis of the effect of increased vegetable and fruit consumption on body weight and energy intake

 

Selection

Performance

Detection

Drop-out

Funding

Food provision

Setting

Diet measurement

Singh 1992 [26]

Unclear

Unclear

Unclear

Low

Unclear

High

High

High

Smith-Warner 2000 [27]

Unclear

Medium

Unclear

Low

Low

High

High

High

Whybrow 2007 [23]

High

Unclear

Unclear

Low

Low

Low

High

Low

Weerts 2009 [30]

Medium

High

Unclear

High

Unclear

Medium

High

High

Chistiensen 2013 [25]

Low

Unclear

Unclear

Low

Unclear

High

High

High

Basu 2010 [29]

Unclear

Medium

Low

Low

High

Low

High

High

Peterson 2011 [28]

Low

Medium

Unclear

Low

High

Low

High

High

Dow 2012 [24]

Medium

High

Low

Low

Low

Low

High

High

  1. Selection bias: low = both method of randomisation and concealment described; medium one of randomisation and concealment described; high = inadequate method of randomisation (e.g. order in which enrolled). Performance bias: low participants blinded to intervention and outcome of weight loss; medium = participants unaware of potential weight loss; high = participants not blinded to group or of potential for weight loss. Detection bias: low = assessors blinded to intervention; high assessors not blinded. Drop-out: low = drop-outs described; high = drop-outs not described. Funding: low = non-industry funding; high = funding by food or vegetable producers. Setting: low = closed living environment (e.g. institution); high = free-living individuals; food provision: low = vegetable or fruits provided; medium = vouchers to buy vegetable or fruits; high = participants advised to eat more fruit or vegetables, but have to purchase themselves. Diet measurement: low = observed or bio-markers measured; high = self-report.