Cureus. 2022 Oct;14(10): e30879
Diabetes mellitus (DM) is a global epidemic causing significant morbidity and mortality. The most occurring DM is type 2 diabetes mellitus (T2DM) which has similar symptoms as type 1 diabetes mellitus (T1DM). However, it is less marked, making it difficult to diagnose during the early stages. The management of T2DM is usually based on weight and glycemic control, which can be achieved through dietary interventions such as intermittent fasting (IF) and the ketogenic diet (KD). Therefore, this systematic review and meta-analysis aim to demonstrate the role of IF and KD in glycemic and weight control among patients with T2DM. Two methods, including an electronic database search through ScienceDirect, Google Scholar, PubMed, Scopus, Embase, and Web of Science, and a manual search were used to identify relevant studies published between 2000 and 2022. The search yielded 1299 articles, of which only 12 met the inclusion criteria. In addition, study quality appraisal was performed using Review Manager software (RevMan 5.4.1). The pooled results have shown that IF had a similar effect on HBA1c reduction as control interventions (standardized mean differences [SMD]: 0.36%; 95% CI; -0.37, 1.10; P = 0.33, I2 = 87%). Similarly, an insignificant difference in weight reduction between IF and control interventions was recorded (SMD: -1.05%; 95% CI; -2.29, 0.19; P = 0.10, I2 = 96%). On the other hand, KD significantly reduced body weight compared with control diets (SMD: -1.91 kg; 95% CI; -2.96 kg, -0.85 kg; P = 0.0004, I2 = 96%). Similarly, KD had a better effect on the HBA1c percentage reduction than control diets (SMD: -2.00%; 95% CI; -3.76, -0.25; P = 0.03, I2 = 97%). IF and KD have shown reductions in HBA1c and body weight among patients with T2DM. However, the interventions are subject to side effects and should be used with caution and under the supervision of a health professional.
Keywords: diabetes mellitus type 2; glycated hemoglobin (hba1c); glycemic control; intermittent energy restriction; intermittent fasting; ketogenic; time-restricted fasting; very low-carbohydrate diet