Dietary interventions and glycaemic control in type 2 diabetes: A systematic review and meta-analysis

Abstract

Background: Advances in science and technology have significantly improved global living conditions, enhancing overall quality of life. However, these changes have also contributed to lifestyle shifts marked by reduced physical activity, increased sedentary behaviour, and altered dietary patterns fueling overnutrition and related non-communicable diseases (NCDs). Among these, type 2 diabetes mellitus (T2DM) has increased sharply over the past three decades, placing a burden on healthcare systems.

Aim: This meta-analysis investigates the effectiveness of dietary interventions in managing T2DM and identifies nutritional strategies associated with improved glycaemic outcomes.

Setting: The review includes studies conducted globally in community and health facility settings.

Method: Peer-reviewed articles published between January 2010 and December 2024 were retrieved from PubMed, Scopus, and Web of Science. Eligible studies focused on dietary interventions for T2DM management. A random-effects model was used for meta-analysis, with effect sizes computed using R Studio. Heterogeneity was assessed using the I² statistic.

Results: Eighteen studies met the inclusion criteria. Dietary interventions significantly improved glycaemic control (mean difference: −0.30%; 95% CI: –0.45 to –0.15), despite high heterogeneity (I² = 93.4%). Interventions focused solely on diet showed a modest effect (MD: –0.17%; 95% CI: –0.33 to –0.00), while intensive lifestyle interventions demonstrated a significantly higher impact (MD: –0.25%; 95% CI: –0.41 to –0.09).

Conclusion: This study reinforces the critical role of lifestyle modifications particularly dietary changes and increased physical activity in managing T2DM. Comprehensive lifestyle interventions are more likely to yield meaningful improvements in glycaemic control.

Contribution: This study highlights the importance of developing and scaling up multifaceted, sustainable strategies to support long-term lifestyle change in individuals living with T2DM.