Inaccurate data in meta-analysis; 'A posteriori dietary patterns and metabolic syndrome in adults: a systematic review and meta-analysis of observational studies' Madam We read with interest the meta-analysis by Shab-Bidar et al. (1) on the association of a posteriori dietary patterns (DP) and metabolic syndrome. We noticed several inaccuracies regarding the inclusion of data that need to be clarified. The authors declare that the meta-analysis was conducted with articles published up to July 2015, but many articles (2-6) meeting the inclusion criteria were not selected and included in the study. We found that the food composition of the DP included in the meta-analysis not always reflected the frequency of consumed foods characterizing the categories 'Unhealthy/Western' and 'Healthy/Prudent' investigated by the authors. They classified and analysed together as 'Healthy/Prudent', DP whose composition differed considerably, as described in the studies by Suliga et al. (7) , Akter et al. (8) , Hong et al. (9) , Kim and Jo (10) and DiBello et al. (11). Similarly, for the analysis of the 'Unhealthy/Western' pattern, they combined different DP described in the studies by Gadgil et al. (12) , Hong et al. (9) , Kim and Jo (10) , DiBello et al. (11) , Noel et al. (13)