Metabolic Impact of Intermittent Fasting in Early Type 2 Diabetes

One known cause of type 2 diabetes (T2DM) is beta-cell dysfunction, which refers to the inability of the beta-cells of the pancreas to produce enough insulin for the body's needs. Unfortunately, no anti-diabetic medication or lifestyle intervention has been shown to prevent the worsening of beta-cell function over time. Interestingly, however, intermittent fasting (IF) - where no food is consumed over a period of time - has been shown to promote weight loss and improve cardio-metabolic function. In individuals with T2DM, it is also been shown to improve glycemic control (i.e. reduce the sugar levels). While no research has studied whether IF can improve pancreatic beta-cell function, the positive metabolic effects suggest that it could provide some benefit. The current study will evaluate whether IF can improve pancreatic beta-cell function in individuals with early T2DM.

Study Overview

• Status: Completed
• Conditions: Obesity; Diabetes Mellitus, Type 2
• Intervention / Treatment: Behavioral: Time restricted feeding; Behavioral: Standard lifestyle

• Study Type: Interventional
• Enrollment (Actual): 51
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5T 3L9
      • Leadership Sinai Centre foe Diabetes - Mount Sinai Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Men and women with type 2 diabetes mellitus diagnosed within preceding 10 years
• Age 20-70 years inclusive
• Body mass index ≥ 25 kg/m2
• Diabetes treatment consisting of lifestyle only, metformin or dipeptidyl peptidase-4 (DPP-4) inhibitor either as monotherapy or in combination
• HbA1c value of 5.5 - 9.0% inclusive

Exclusion Criteria:

• Current diabetes treatment with insulin, glucagon-like peptide-1 receptor agonists, sodium-glucose co-transporter 2 (SGLT-2) and/or sulfonylureas
• Involvements in any other clinical study on lifestyle intervention or requiring drug therapy
• Any history or eating disorder
• Renal dysfunction as evidenced by estimated glomerular filtration rate <45 mL/min by Modification of Diet in Renal Disease (MDRD) formula
• Hepatic disease considered to be clinically significant (includes jaundice, chronic hepatitis, or previous liver transplant) or transaminases >2.5x the upper limit of normal
• Malignant neoplasm requiring chemotherapy, surgery, radiation or palliative therapy within the previous 5 years (with the exception of basal cell skin cancer)
• Any other factor likely to limit adherence to the study, in the opinion of the investigators

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intermittent fasting (time restricted feeding); Intermittent fasting (IF) study arm consisting of time restricted feeding with 20 hours of fasting and a 4 hour window of feeding (between 4 and 8 PM or between 5 to 9 PM).	Behavioral: Time restricted feeding; Restricted feeding with 20 hours of fasting and a 4 hour window of feeding (between 4 and 8 PM or between 5 to 9 PM).
Active Comparator: Standard lifestyle; Standard lifestyle recommendation as per the Diabetes Canada guidelines, where participants are encouraged to maintain regularity in timing and spacing of means with no specific recommendations regarding the hours of fasting	Behavioral: Standard lifestyle; Standard lifestyle recommendations

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pancreatic beta-cell function	The difference in percentage change in beta-cell function between each intervention period, measured using the Insulin Secretion-Sensitivity Index-2 (ISSI-2)	at week 16

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fasting glucose	Difference in change in fasting glucose between each intervention period	at week 16

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
BMI	Difference in change in BMI between each intervention period	at week 16
Waist circumference	Difference in change in waist circumference between each intervention period	at week 16
Central abdominal fat mass on Dual X-ray Absorptiometry (DEXA)	Difference in change in central abdominal mass between each intervention period	at week 16
Insulin sensitivity	Difference in insulin sensitivity measured by the Matsuda Index between each intervention period	at week 16
Satiety	Difference in hunger assessed by Visual Analogue Scales (0 to 10mm with increased values associated with increased hunger) between each intervention period	at week 16

Collaborators and Investigators

• Sponsor: Mount Sinai Hospital, Canada

Publications and helpful links

General Publications

• Kramer CK, Zinman B, Feig DS, Retnakaran R. Effect of Time-Restricted Eating on beta-Cell Function in Adults With Type 2 Diabetes. J Clin Endocrinol Metab. 2025 May 19;110(6):e2045-e2053. doi: 10.1210/clinem/dgae594.

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2021
• Primary Completion (Actual): June 1, 2023
• Study Completion (Actual): June 1, 2023

Study Registration Dates

• First Submitted: January 20, 2023
• First Submitted That Met QC Criteria: January 30, 2023
• First Posted (Actual): February 8, 2023

Study Record Updates

• Last Update Posted (Estimated): October 3, 2025
• Last Update Submitted That Met QC Criteria: September 29, 2025
• Last Verified: January 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Endocrine System Diseases; Nutrition Disorders; Metabolic Diseases; Overnutrition; Body Weight; Glucose Metabolism Disorders; Diabetes Mellitus; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; Diabetes Mellitus, Type 2
• Other Study ID Numbers: 19-0299-A

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No