Current Advances and Future Prospects in the Use of a Low-Carbohydrate Diet in Managing People with Type 2 Diabetes: A Systematic Review of Randomised Controlled Trials

Background: There is a worldwide increase in the prevalence of type 2 diabetes, and strategies for managing this condition include dietary interventions. These interventions include the use of a low-glycaemic index diet, high-fibre and prebiotic diets, and low-carbohydrate diets (LCDs), which improve glycaemic control, reduce the risk of diabetic complications, and promote health. However, the definition of LCDs varies across the literature, and the use of LCDs in managing people with diabetes is often seen as controversial. Therefore, the aim of this review is to examine current advances and future prospects in the use of LCDs in managing people with type 2 diabetes. Method: A systematic review of randomised controlled trials, which applied both the PRISMA and PICOS frameworks. Databases including MEDLINE, APA PsycInfo, Academic Search Premier, CINAHL Plus with Full Text, APA PsycArticles, and Psychology and Behavioural Sciences Collection were searched through EBSCOHost. The EMBASE database and reference list of articles were also searched for articles of interest. Two researchers conducted the searches independently from database inception to 28 August 2025. However, based on the inclusion criteria, the year of publication of studies was restricted to articles published from 2021. The search terms were combined using Boolean operators (AND/OR), and duplicates were removed in EndNote. The articles were screened for eligibility based on inclusion and exclusion criteria by two researchers. Results: The findings identified that an LCD is significantly ( p < 0.05) more effective in reducing glycaemic parameters compared to a usual diet, standard care, or a control diet in people with type 2 diabetes. Similarly, the effect of LCD was significant ( p < 0.05) in reducing BMI in patients with type 2 diabetes compared with the control diet. However, an LCD did not appear to have a significant ( p > 0.05) effect on lipid parameters compared to a control diet. Conclusion: This systematic review found that LCDs are significantly ( p < 0.05) more effective in promoting glycaemic control than a usual diet, standard care, or a control diet in people with type 2 diabetes. In addition, LCDs can be an effective strategy for reducing BMI in individuals with type 2 diabetes, particularly when implemented as part of a structured, sustained dietary intervention. However, there was variability in the findings of the studies included with respect to glycaemic control and BMI. Furthermore, the impact of LCD on glycaemic control did not appear sustainable in the long term. LCDs did not have a significant ( p > 0.05) effect on lipid parameters compared to a control diet.