Carbohydrate restriction for glycaemic control in Type 2 diabetes: a systematic review and meta‐analysis

Aim To conduct a systematic review and meta‐analysis to evaluate the effect of carbohydrate restriction on glycaemic control in Type 2 diabetes. Methods We searched Medline, EMBASE and CINAHL for the period between 1976 and April 2018. We included randomized controlled trials comparing carbohydrate restriction with a control diet which aimed to maintain or increase carbohydrate intake, and that reported HbA1c as an outcome and reported the amount of carbohydrate consumed during or at the end of the study, with outcomes reported at ≥3 months. Results We identified 1402 randomized controlled trials, 25 of which met the inclusion criteria, incorporating 2132 participants for the main outcome. Definitions of low carbohydrate varied among the studies. The pooled effect estimate from meta‐analysis was a weighted mean difference of –0.09% [95% CI –0.27, 0.08 (P = 0.30); I2 72% (P