An interventional study of Standardized TRE Protocol and Personalized TRE Protocol in Metabolic Disturbance, sponsored by University of Toronto. Completed at 1 site in Canada. Open to female participants aged 50 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-10-01.
Sponsored by University of Toronto · Not applicable, Interventional, and Treatment
This study will evaluate the implementation and effectiveness of free-living TRE on biological and behavioural breast cancer risk factors.
TRE is an eating pattern where individuals consume ad libitum energy intake within a set window of time, commonly 8 hours, which induces a fasting window of 16 hours per day (i.e., 16:8 TRE). TRE is a simple and accessible lifestyle intervention with high adherence potential that may target both biological and behavioural mechanisms of breast cancer risk.
University of Toronto is the lead sponsor of 397 studies on the registry; 59 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Participants will be asked to follow a standardized 16:8 TRE protocol with an 11 am to 7 pm eating window for 16 weeks. Participants receive support to follow the TRE intervention from the study team which will include an initial consultation with a registered dietitian and ongoing tailored feedback via brief support calls from study staff at weeks 1, 3, 6, and 12.
Behavioral: Standardized TRE Protocol · Behavioral: External Support for TRE
Participants will be asked to follow a standardized 16:8 TRE protocol with an 11 am to 7 pm eating window for 16 weeks. Each participant will be matched with another participant in the same group to provide peer-based support to adhere to TRE. Study staff will introduce pairs and provide an introduction to TRE and then pairs will meet by phone/video at weeks 1, 3, 6, and 12 at a minimum, with additional contact encouraged.
Behavioral: Standardized TRE Protocol · Behavioral: Peer Support for TRE
Participants will be asked to follow TRE for 16 weeks with a protocol that is personalized to their preferences within the following pre-specified rules: 1) 8-10 hour eating window; 2) self-selected eating window start time as long as it ends ≥3h before bedtime; 3) if days off are required, aim to do so after following TRE for ≥5 successive days each week. Participants receive support to follow the TRE intervention from the study team which will include an initial consultation with a registered dietitian and ongoing tailored feedback via brief support calls from study staff at weeks 1, 3, 6, and 12.
Behavioral: Personalized TRE Protocol · Behavioral: External Support for TRE
Participants will be asked to follow TRE for 16 weeks with a protocol that is personalized to their preferences within the following pre-specified rules: 1) 8-10 hour eating window; 2) self-selected eating window start time as long as it ends ≥3h before bedtime; 3) if days off are required, aim to do so after following TRE for ≥5 successive days each week. Each participant will be matched with another participant in the same group to provide peer-based support to adhere to TRE. Study staff will introduce pairs and provide an introduction to TRE and then pairs will meet by phone/video at weeks 1, 3, 6, and 12 at a minimum, with additional contact encouraged.
Behavioral: Personalized TRE Protocol · Behavioral: Peer Support for TRE
Participants will be asked to maintain their usual diet and physical activity patterns for 16 weeks. They will receive the same number and timing of calls from study staff as the other groups (at randomization, 1, 3, 6, 12 weeks).
A standardized 16:8 TRE protocol with an 11 am to 7 pm eating window.
A personalized TRE protocol following pre-specified rules: 1) 8-10 hour eating window; 2) self-selected eating window start time as long as it ends ≥3h before bedtime; 3) if days off are required, aim to do so after following TRE for ≥5 successive days each week.
External support (from study staff) that includes consultation with a registered dietitian and ongoing tailored feedback via support calls at weeks 1, 3, 6, and 12.
Matched pairs will meet by phone/video at weeks 1, 3, 6, and 12.
Adherence to TRE for the 16-week intervention
Assessed daily through twice daily automated text messages asking participants to respond with what time they started and stopped eating that day.
Time frame: 16-week average
Hemoglobin A1c
Collected via venipuncture
Time frame: 16 Weeks
HOMA-IR
Homeostatic Model Assessment for Insulin Resistance calculated as fasting glucose in mmol/l\*fasting insulin in μU/ml/22.5
Time frame: 16 Weeks
Free-living glucose control
Participants will be provided with a Dexcom G6 continuous glucose monitor transmitter and sensor. This data will be evaluated as the 5-day average of: 24-hour, daytime, and nocturnal glucose concentration, time in hyper, normo and hypoglycemia, and glycemic variability
Time frame: 16 Weeks
C-Reactive Protein
Measured via venipuncture and core lab lab analysis
Time frame: 16 Weeks
Lipid profile
Measured via venipuncture and core lab lab analysis
Time frame: 16 Weeks
Body weight
Measured via Fitbit Aria Air scale at baseline and 16-weeks but also once per week to evaluate trajectory of change
Time frame: 16 Weeks
Waist circumference
Measured via provided circumference measuring tape as the average of 2 measurements
Time frame: 16 weeks
Blood Pressure
Participant will be provided with a Bios 3al1-3e blood pressure measuring device. After 5 minutes of quiet seated rest, blood pressure will be measured 6 times, 60 seconds apart in a standardized seated position with the average of the 2nd through 6th measurement used.
Time frame: 16 Weeks
10-year cardiovascular disease risk
Calculated via both the Framingham and Reynolds 10-year CVD risk scores using measured collected for study purposes (i.e., age, total cholesterol, HDL, systolic blood pressure, smoking status, C-reactive protein, family history of heart disease).
Time frame: 16 Weeks
Metabolic syndrome (NCEP/ATP III criteria)
As defined by the NCEP/ATP III criteria using measurements taken using provided study tools
Time frame: 16 Weeks
Metabolic syndrome z-score
As defined by the NCEP/ATP III criteria and age and ethnic specific calculations
Time frame: 16 Weeks
Alanine Aminotransferase
Measured via venipuncture and core lab lab analysis
Time frame: 16 Weeks
TRE acceptability and appropriateness
Evaluated via an 'End of Study Survey' (including a Diet Satisfaction Score Tool and acceptability questions) and semi-structured qualitative interviews
Time frame: 16 Weeks
TRE Adoption
Evaluated as uptake of each delivery model, defined as adherence to the intervention touch points (i.e., external support: support calls with staff; peer support: number of peer interactions; both: response rate to adherence).
Time frame: 16 Weeks
Cost of intervention delivery
Intervention costs will be evaluated and averaged per participant from the time required for intervention phone calls, scheduling, and technical support for adherence app by the study staff according to hourly rates of pay.
Time frame: 16 Weeks
TRE Sustainability
Evaluated via participant self-report of continued TRE post-intervention
Time frame: 1, 2, 3, and 4 months post intervention period
TRE Adverse Events
Measured via experience of selected relevant Common Terminology Criteria for Adverse Events (CTCAE v5) with additional questions about duration and change in the revised 18-item version of the Three-Factor Eating Questionnaire (aka Eating Inventory)
Time frame: 16 Weeks
Health-related quality of life
Measured by the RAND-36 Physical Component Summary. Physical component summary of the RAND-36 questionnaire (minimum = 0, maximum = 50, a higher score is a better outcome)
Time frame: 16 Weeks
Sleep duration
Measured via FitBit Inspire 2 as 7-day average
Time frame: 16 Weeks
Sedentary time
Measured via FitBit Inspire 2 as 7-day average
Time frame: 16 Weeks
Physical activity
Measured via FitBit Inspire 2 as 7-day average
Time frame: 16 Weeks
Anxiety
Evaluated via the Hospital Anxiety and Depression Scale (HADS); This 14-item questionnaire has a minimum score of 0 and maximum of 21, where a higher score is worse.
Time frame: 16 weeks
Depression
Evaluated via the Hospital Anxiety and Depression Scale (HADS); This 14-item questionnaire has a minimum score of 0 and maximum of 21, where a higher score is worse.
Time frame: 16 weeks
Plan to share: No
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