Meat and fish intake and type 2 diabetes: Dose–response meta-analysis of prospective cohort studies

This meta-analysis aimed to quantitatively examine the possible associations between total meat, red meat, processed meat, poultry and fish intakes and type 2 diabetes (T2D). Relevant articles were identified in PubMed, Embase and Web of Science databases using a search time up to January 2019. Generalized least-squares trend estimations and restricted cubic spline regression models were used for analysis. Twenty-eight articles were included in the analysis. When comparing the highest with the lowest category of meat intake, the summary relative risk of T2D was 1.33 (95% CI: 1.16–1.52) for total meat, 1.22 (95% CI: 1.16–1.28) for red meat, 1.25 (95% CI: 1.13–1.37) for processed meat, 1.00 (95% CI: 0.93–1.07) for poultry and 1.01 (95% CI: 0.93–1.10) for fish. In the dose–response analysis, each additional 100g/day of total and red meat, and 50g/day of processed meat, were found to be associated with a 36% (95% CI: 1.23–1.49), 31% (95% CI: 1.19–1.45) and 46% (95% CI: 1.26–1.69) increased risk of T2D, respectively. In addition, there was evidence of a non-linear dose–response association between processed meat and T2D (P=0.004), with the risk increasing by 30% with increasing intakes up to 30g/day. Our meta-analysis has shown a linear dose–response relationship between total meat, red meat and processed meat intakes and T2D risk. In addition, a non-linear relationship of intake of processed meat with risk of T2D was detected.