Dietary inflammatory index in relation to obesity and body mass index: a meta-analysis

Abstract

Purpose Studies investigating the association between dietary inflammatory index (DII) and body mass index (BMI) have led to inconsistent findings. Therefore, to decisively conclude, this paper aims to clarify the relationship between DII and obesity by performing meta-analysis. Design/methodology/approach PubMed, Scopus and Google Scholar were searched up to July 2017 using key words selected from Medical Subject Headings and other related keywords to identify all relevant articles. In total, 22 articles were entered into the meta-analysis; 22 studies compared the mean of BMI among subjects with highest versus the lowest DII and 4 studies had data on the hazard risk (HR) or odds ratio (OR) for obesity. Findings A meta-analysis on included studies indicated a significant association on either mean differences (MD) in BMI (MD = 0.811; 95 per cent CI: 0.365-1.256; p: 0.0001) or obesity OR (OR: 1.310; 95 per cent CI: 1.144-1.500; p = 0.000) by comparing the highest and lowest DII categories. Between-study heterogeneity was high (Cochrane Q test, p < 0.001, I2 = 98.1 per cent, df = 21, τ2 = 0.9273), and only dietary assessment methods could explain the source of heterogeneity in which 24-h dietary recalls were homogeny (I2 = 8.4 per cent, df = 2, p = 0.335). Originality/value The results of the present meta-analysis suggest that adherence to high DII score increased BMI and obesity. More prospective studies in different populations are needed to better clarify this relation.