Time-Restricted Dietary Intervention as a Metabolic Regulator in Type 2 Diabetes Mellitus: A Systematic Review of Evidence From Human and Rodent Studies

CONTEXT: Time-restricted feeding (TRF) has emerged as a promising dietary strategy for improving metabolic health, including type 2 diabetes mellitus (T2DM). OBJECTIVE: To explore the effects of TRF on body weight, glucose regulation, insulin sensitivity, and lipid metabolism in animal and human studies. DATA SOURCES: A systematic search of the PubMed and Scopus databases was conducted from February 24, 2025, to April 2, 2025, to identify animal and human studies investigating the metabolic effects of TRF. DATA EXTRACTION: The search strategy combined keywords related to "intermittent fasting," "diabetes," "time-restricted feeding," "TRF," "animal model," "insulin sensitivity," "glucose level," "T2DM," "body composition," "human," "glycemic control," and "insulin resistance." Studies were included if they reported the effects of TRF on at least 1 of the following end points: body weight, blood glucose level, insulin sensitivity, glucose tolerance, or lipid profile. Reviews, commentaries, and studies lacking relevant outcome data were excluded. A total of 11 studies met the inclusion criteria: 6 animal and 5 human investigations. DATA ANALYSIS: Across animal and human studies, TRF had duration-dependent metabolic effects. In animal models, short-term TRF (4-5 weeks) elicited modest improvements in glucose tolerance and body weight, whereas longer interventions (6-12 weeks) consistently enhanced glycemic control, reduced body weight, and favorably modulated lipid profiles. In humans, short-term time-restricted eating (3-4 weeks) produced modest reductions in fasting glucose levels and glycated hemoglobin (HbA1c), and extended interventions (12-24 weeks) improved insulin sensitivity, lowered HbA1c, and further optimized lipid metabolism and body weight. CONCLUSION: TRF demonstrates therapeutic potential in managing T2DM by improving glucose regulation, insulin sensitivity, and lipid metabolism in animal and human models. Interventions extending beyond 6 weeks and with fasting windows of 14-16 hours yield the most consistent metabolic benefits, highlighting the need for standardized TRF protocols in future research. SYSTEMATIC REVIEW REGISTRATION: Open Science Framework registration doi: 10.17605/OSF.IO/6MAQ9.