An evidence‐based approach to developing low‐carbohydrate diets for type 2 diabetes management: A systematic review of interventions and methods

Abstract Aim To identify core diet and delivery components of low‐carbohydrate (CHO) diets that have demonstrated efficacy for type 2 diabetes (T2D) management. Materials and methods MEDLINE, Pre‐MEDLINE, EMBASE, CINAHL and the Cochrane Library of Controlled Trials databases were systematically searched from inception until August 18, 2018. Primary intervention studies of low‐CHO diets (≤130 g/d or 26% total energy intake [TEI]) were included. Content analysis was performed on the low‐CHO diet protocols classified as safe and effective for T2D management. Results A total of 41 studies published between 1963 and 2018 were included, of which 40 were classified as safe and effective for inclusion in the primary analysis. Thirteen studies (13/40) were on very‐low‐CHO diets (<50 g/d), 14/40 included low‐CHO diets (≤130 g/d or 26% TEI), and 13/40 were adapted according to participant progress. Thirty‐one studies reported a total energy prescription, of which 18/31 encouraged ad libitum intakes. Twenty studies reported a prescribed dietary fat amount, of which 18/20 were unrestricted or high‐fat (>35% TEI). Twenty‐six studies reported a prescribed dietary protein amount, of which 22 were unrestricted or were high‐protein (>25% TEI). The types of dietary CHO, fat and protein recommended were predominantly whole foods. Common delivery methods reported were dietician and/or physician involvement, moderate to high frequency of contact (≥1 session/month) and use of participant self‐monitoring. Conclusions Multiple approaches for developing and delivering a low‐CHO diet intervention for T2D management are safe and effective. A comprehensive set of core dietary components to consider in the formulation of low‐CHO diet protocols were identified for use in clinical practice and to inform evidence‐based guidelines for T2D management.