Effects of time-restricted eating on markers of glucose metabolism and regulation in individuals with prediabetes or type 2 diabetes: a systematic review and meta-analysis of randomised controlled trials
Viple F, Pedersen SS, Andersen TH, Raben A, Termannsen AD, Salling J
Diabetologia · 0 citations
Review labels
Neutral facts our review recorded about how this study was done. They describe method, never whether we like the result.
How it was studied
- Design
- Meta-analysis (indexed by PubMed)
- Studied in
- People
- Main outcome
- Health markers and function
Who paid for it
- Funding
- Funding not disclosed
Publication
- Published
- 2026-07-27 · Diabetologia · vol. 69 · issue 10 · pp. 2741–2758
- Publisher
- Springer Science+Business Media
- Cited
- 0 citations · more than 56% of similar papers · 0.0× the field average
- References
- 46 works
- Access
- Open access (hybrid journal) · CC-BY-NC-SA
- Research areas
- Dietary Effects on Health · Enhanced Recovery After Surgery · Circadian rhythm and melatonin
- Keywords
- Prediabetes, Diabetes mellitus, Type 2 diabetes, Meta-analysis, Randomized controlled trial, Impaired fasting glucose, MEDLINE, Confounding
- MeSH
- humans, diabetes mellitus, type 2, prediabetic state, blood glucose, fasting, female, randomized controlled trials as topic, biomarkers, glycated hemoglobin, intermittent fasting
6 authors
From DK, GB
- Frida VipleUniversity of Copenhagen; Steno Diabetes Centers; Copenhagen University Hospital; Steno Diabetes Center Copenhagen
- Sofie S. PedersenUniversity of Copenhagen; Steno Diabetes Centers; Copenhagen University Hospital; Steno Diabetes Center Copenhagen
- Tue Helms AndersenSteno Diabetes Centers; Copenhagen University Hospital; Steno Diabetes Center Copenhagen
- Anne RabenUniversity of Copenhagen; Steno Diabetes Centers; Copenhagen University Hospital; Steno Diabetes Center Copenhagen
- Anne‐Ditte TermannsenUniversity of Copenhagen; Steno Diabetes Centers; Copenhagen University Hospital; Steno Diabetes Center Copenhagen
- Jonas Salling Quist · correspondingUniversity of Copenhagen; University of Leeds; Steno Diabetes Centers; Steno Diabetes Center Copenhagen
Abstract
Aims/hypothesis
This systematic review and meta-analysis aimed to investigate the effects of time-restricted eating (TRE) on glucose metabolism and regulation in individuals with prediabetes (fasting blood glucose of 5.6-6.9 mmol/l or HbA1c of 39-47 mmol/mol [5.7-6.4%]) or type 2 diabetes (fasting blood glucose ≥7 mmol/l or HbA1c ≥48 mmol/mol [6.5%]).
Methods
A literature search was performed in MEDLINE, Embase and CENTRAL from inception to 5 August 2025. Moreover, forward and backward citation searches were performed. Eligible studies were RCTs in adults with prediabetes or type 2 diabetes, lasting ≥2 weeks, reporting markers of glucose metabolism and regulation, comparing TRE (≤12 h eating window) with a non-time-restricted control diet. Studies involving pregnancy, other fasting regimens, or non-peer-reviewed publications were excluded. Data were pooled as weighted mean differences with 95% CIs using random-effects generic inverse variance models in Cochrane Review Manager Web, and results are presented as forest plots. The certainty of evidence was defined using Grading of Recommendations, Assessment, Development and Evaluations methodology, and risk of bias was estimated by using the Revised Cochrane risk-of-bias tool for randomised trials (RoB 2).
Results
Out of 2043 records identified through the database search, as well as 1249 from forward and backward citation searches, ten RCTs including 599 participants were included. The mean length of the studies was 4 months, and the eating windows ranged from 4 to 10 h per day. The pooled meta-analysis showed no overall effect of TRE on HbA1c (-3.33 mmol/mol; 95% CI -6.87, 0.20 (-0.30% points; -0.63, 0.02); p=0.06, moderate certainty). Nevertheless, following stratification by subgroups, TRE resulted in a reduction in HbA1c of 0.93 mmol/mol (-1.70, -0.17 [-0.09% points; -0.16, -0.02]; p=0.02) in individuals with prediabetes but not in individuals with type 2 diabetes (-4.68 mmol/mol; -10.08, 0.72 (-0.43% points; -0.92, 0.07); p=0.09). TRE reduced fasting blood glucose in the pooled analysis (-0.30 mmol/l; -0.53, -0.07; p<0.01, moderate certainty) as well as in the subgroup analyses in individuals with prediabetes (-0.14 mmol/l; -0.27, -0.01; p=0.03) and with type 2 diabetes (-0.48 mmol/l; -0.78, -0.17; p<0.01). Moreover, TRE lowered body weight by 1.6 kg (-2.2, -1.0; p<0.001) in the pooled analysis. The evidence was limited by imprecision arising from wide confidence intervals in some of the included studies, which may be due to small sample sizes. Lastly, the effects of TRE on markers of insulin sensitivity, beta cell function and continuous glucose monitoring measurements were inconclusive.
Conclusions/interpretation
Moderate-certainty evidence indicates that TRE reduces fasting blood glucose but not HbA1c. The subgroup analyses revealed that TRE improved HbA1c and fasting glucose in individuals with prediabetes and improved fasting glucose in individuals with type 2 diabetes. Future large-scale studies should investigate long-term effects of TRE in prevention and treatment of type 2 diabetes.
Trial registration
PROSPERO CRD42024523591 FUNDING: This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors. Three authors (JS, A-DT, THA) are employed at Steno Diabetes Center Copenhagen, a public hospital and research institution under the Capital Region of Denmark, partly funded by a grant from the Novo Nordisk Foundation.
Abstract via Europe PMC. Copyright remains with the authors or publisher.
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