The REmission of Diabetes Using a PlAnt-based Weight Loss InteRvention (REPAIR) Trial (REPAIR)

Effects of Plant-based Dietary Patterns on Diabetes Remission: the REmission of Diabetes Using a PlAnt-based Weight Loss InteRvention (REPAIR) Trial

The goal of this clinical trial is to learn if a plant-based intensive lifestyle intervention can achieve remission of diabetes. It will also learn if a plant-based intensive lifestyle intervention can achieve weight loss ≥15% of initial body weight.

The main questions it aims to answer are:

• What proportion of participants achieved diabetes remission (normal blood sugar for at least 3 months without medication)?
• What proportion of participants achieved ≥15% weight loss from their initial weight?
• What is the impact on weight, body composition, blood pressure, blood sugars, cholesterol and inflammation levels?

Researchers will compare the plant-based intensive lifestyle intervention to the current standard of care.

Participants will be randomly placed into one of two groups:

1. Standard of care, where they will continue their usual diabetes care with their health care providers
2. Plant-based intensive lifestyle intervention, where they will follow a diet and exercise program

Participants in the standard of care will:

• Continue with their usual diabetes care for 12 months
• Attend clinic visits on 5 occasions over the 12 months
• Allow study staff to take measurements (e.g. weight, blood pressure)
• Provide blood samples
• Track their food and exercise and complete questionnaires

Participants in the plant-based intensive lifestyle intervention will:

• Follow a plant-based low calorie diet for 3 months followed by a calorie-balanced plant-based diet for 9 months
• Participate in a 16-week exercise program
• Attend clinic visits every 2-4 weeks over the 12 months
• Allow study staff to take measurements (e.g. weight, blood pressure)
• Provide blood sample
• Track their food and exercise and complete questionnaires

Study Overview

• Status: Not yet recruiting
• Conditions: Diabetes Mellitus
• Intervention / Treatment: Behavioral: Plant-based intensive lifestyle intervention; Other: Standard of Care

• Study Type: Interventional
• Enrollment (Estimated): 160
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Research Study Coordinator; Phone Number: 416-867-7474; Email: REPAIRtrial@unityhealth.to

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada
      • Unity Health Toronto (St. Michael's Hospital)
      • Contact: Research Study Coordinator; Phone Number: 416-867-7474; Email: REPAIRtrial@unityhealth.to

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age of 18 years;
• Equal number of males and females;
• Obese (body mass index [BMI] and waist circumference using sex and ethnic-specific thresholds for obesity and significant abdominal adiposity);
• Diagnosed with type 2 diabetes within the last 6 years;
• Treated by non-insulin antihyperglycemic therapy;
• Have an HbA1c 6.0-10.0%;
• Taking a stable dose of antihypertensive, antihyperglycemic, or antihyperlipidemic medications for ≥3-months, if applicable;
• Have a family physician and an Ontario Health Card;

Exclusion Criteria:

• Type 1 diabetes;
• HbA1c <6.0% or >10%;
• Recent weight loss (≥5 kg) in the last 6 months;
• Treated with diet alone;
• Treated with insulin;
• Treated with GLP-1/GIP/glucagon receptor agonist therapies;
• Treated with other anti-obesity drugs;
• Eating disorder, substance abuse disorder, serious depression, psychiatric disorder;
• Allergy or intolerance to soy;
• Allergy or intolerance to peanuts, tree nuts and seeds (all three);
• Pregnant or intending pregnancy;
• Currently breastfeeding;
• Bariatric or surgery in the last 6 months;
• Major cardiovascular event in the last 6 months;
• Kidney dysfunction;
• Unstable or severe heart failure;
• Major illness or chronic infection;
• Atherosclerotic cardiovascular disease (ASCVD);
• Chronic kidney disease (CKD);
• Treated for cancer in the last 12 months;
• Participating in another trial;
• Told by a doctor to refrain from physical activity;
• Any condition that would prevent you from following study procedures;
• Family physician does not consent to your participation

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: plant-based intensive lifestyle intervention; Participants will undergo a plant-based intensive lifestyle intervention targeting weight loss with the goal of achieving diabetes remission. All antihyperglycemic and/or antihypertensive medications will be stopped at the first visit as a safety measure. The interventions will be delivered at clinic visits at 2-4week intervals over the 52-weeks.	Behavioral: Plant-based intensive lifestyle intervention; The plant-based intensive lifestyle intervention has 2 phases. The first 12-weeks is a weight loss phase consisting of a plant-based, high-plant protein energy restricted total diet replacement (TDR), psyllium-based fibre and complete multivitamin supplements, and vegetable bouillon, with the option of continuing with this phase up to week 20. The second phase is weight-loss maintenance beginning with an 8-week (weeks 12-20) stepped food reintroduction phase with partial meal replacement, progressing towards the 32-week (weeks 20-52) full food introduction phase. These phases focus on introducing a plant-based, high-plant protein, energy balanced, weight loss maintenance diet, which will be supported by a digital program. At weeks 12-28, a 16-week in-person structured exercise training program will be delivered followed by 2-weekly motivational phone calls until the 52-weeks. A 19-session, group-based, structured behavioural support program will be delivered throughout the study.
Active Comparator: standard of care; Participants will continue to receive usual diabetes and obesity management with their health care provider(s) as per current Canadian clinical practice guidelines. Participants will attend clinic visits on 5 occasions over the 52-weeks.	Other: Standard of Care; Participants will continue to receive usual diabetes and obesity management as per current Canadian clinical practice guidelines. The management will continue to be delivered to participants through their family doctor, nurse practitioner, or diabetes care team with standard frequency of contact. Participants will attend clinic visits on 5 occasions (weeks 0, 12, 28, 40 and 52) and will receive motivational phone calls between visits to provide reminders regarding follow-up with their diabetes care providers.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion achieving diabetes remission	Proportion achieving diabetes remission, defined as an HbA1C <6.5% for ≥3 months free of antihyperglycemic medications at 52 weeks.	From enrollment to the end of treatment at 52 weeks.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Key secondary: Proportion achieving ≥15% weight loss	Proportion achieving ≥15% weight loss from baseline at 52 weeks.	From enrollment to the end of treatment at 52 weeks.
Proportion achieving ≥10% and ≥5% weight loss from baseline change	Proportion achieving ≥10% and ≥5% weight loss from baseline at 52 weeks	From enrollment to the end of treatment at 52 weeks
Changes in measures of body composition	Changes in body weight	From enrollment to the end of treatment at 52 weeks.
Changes in measures of body composition	Changes in body mass index	From enrollment to the end of treatment at 52 weeks.
Changes in measures of body composition	Changes in waist circumference	From enrollment to the end of treatment at 52 weeks.
Changes in measures of body composition	Changes in body fat	From enrollment to the end of treatment at 52 weeks.
Changes in measures of body composition	Changes in lean body mass	From enrollment to the end of treatment at 52 weeks.
Proportion experiencing relapse	Proportion experiencing relapse, defined as having achieved remission at any time during the trial but having an HbA1c ≥6.5% at 52 weeks.	From enrollment to the end of treatment at 52 weeks.
Changes in functional tests	Changes in sit-stand chair	From enrollment to the end of treatment at 52 weeks.
Changes in functional tests	Changes in grip test	From enrollment to the end of treatment at 52 weeks.
Changes in glycemic control	Changes in HbA1c	From enrollment to the end of treatment at 52 weeks.
Changes in glycemic control	Changes in fasting plasma glucose	From enrollment to the end of treatment at 52 weeks.
Changes in blood lipids	Changes in LDL-cholesterol, non-HDL cholesterol, HDL-cholesterol, total cholesterol and triglycerides.	From enrollment to the end of treatment at 52 weeks.
Changes in blood pressure	Changes in systolic and diastolic blood pressure.	From enrollment to the end of treatment at 52 weeks.
Changes in inflammation	Changes in c-reactive protein (CRP)	From enrollment to the end of treatment at 52 weeks

Collaborators and Investigators

• Sponsor: University of Toronto
• Collaborators: Unity Health Toronto
• Investigators: Principal Investigator: Dr. Laura Chiavaroli, MSc, PhD, University of Toronto; Principal Investigator: Dr. John L Sievenpiper, MD, PhD, FRCPC, University of Toronto, St. Michael's Hospital; Principal Investigator: Dr. David JA Jenkins, OC, MD, PhD, DSC, FRCP, FRCPSC, University of Toronto, St. Michael's Hospital; Principal Investigator: Dr. Cyril WC Kendall, PhD, University of Toronto

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2025
• Primary Completion (Estimated): December 19, 2028
• Study Completion (Estimated): December 30, 2029

Study Registration Dates

• First Submitted: March 17, 2025
• First Submitted That Met QC Criteria: March 25, 2025
• First Posted (Actual): April 2, 2025

Study Record Updates

• Last Update Posted (Actual): April 2, 2025
• Last Update Submitted That Met QC Criteria: March 25, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: exercise; weight loss; diet; plant-based; behavioural intervention; diabetes remission; intensive lifestyle intervention; digital program
• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Body Weight; Body Weight Changes; Glucose Metabolism Disorders; Weight Loss; Diabetes Mellitus
• Other Study ID Numbers: REB 24-227

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All outcomes listed will be shared in an anonymous/de-identified format.
• IPD Sharing Time Frame: IPD and supporting information will be available after the anticipated study completion date from January 2030 and will remain for 30 years until January 2060.
• IPD Sharing Access Criteria: IPD data will be accessible though the University of Toronto Dataverse (https://borealisdata.ca/dataverse/toronto). The metadata record of our dataset will be public, however access to the data will be restricted. Users will need to request access using the contact information provided in order to view and download our restricted files.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

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