Intermittent fasting versus continuous energy-restricted diet for patients with type 2 diabetes mellitus and metabolic syndrome for glycemic control: A systematic review and meta-analysis of randomized controlled trials
Meta-analysis of four RCTs (n=355) in overweight/obese adults with type 2 diabetes and metabolic syndrome found no glycemic superiority of intermittent fasting over continuous energy restriction for HbA1c or fasting glucose, but intermittent fasting produced modestly greater weight loss (−1.70 kg) with similar hypoglycaemia and lipid changes.
Design
RCTs through Sept 2020 comparing intermittent fasting (IF) vs continuous energy-restricted diets (CERD) in T2DM + metabolic syndrome; 4 trials (355 participants) entered meta-analyses.
Glycemic endpoints (pooled MDs vs CERD)
- HbA1c: −0.06 absolute percentage points (95% CI −0.27 to 0.16) — not statistically different
- Fasting glucose: pooled MD −0.27 (95% CI −0.76 to 0.22) in abstract units reported by authors (verify mmol/L vs mg/dL in full text)
Weight
- IF vs CERD: −1.70 kg (95% CI −3.28 to −0.11) favouring IF
Safety / lipids
Abstract reports similar hypoglycaemic events and similar fasting insulin / lipid profile changes between patterns under included trials.
Publication
Wang Y, Li S, Liu Y, et al. Diabetes Res Clin Pract. 2021 Sep;179:109003. PMID 34391831.
Outcomes
- HbA1c (Glycated Hemoglobin)-0.06% (Absolute Change)
- Fasting glucose MD −0.27 (95% CI −0.76 to 0.22)—CI includes null (units per original meta-analysis; see full text).
- Weight change MD −1.70 kg (95% CI −3.28 to −0.11) favouring intermittent fasting vs continuous energy restriction (4 RCTs, n=355).