Time-restricted Eating in Survivors Trial

Study Overview
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Brief Summary
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Breast cancer survivors aged 60+ and with overweight/obesity who had completed chemotherapy 1-6 years earlier completed 8 weeks of 12-8 pm weekday-only time-restricted eating. The intervention was delivered by a registered dietitian call, twice-daily automated text messages asking about eating start/stop times, and three support phone calls.

Official Title
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Time-restricted Eating in Survivors Trial

Conditions
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Cancer, Breast

Intervention / Treatment
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* Behavioral: Time-restricted eating


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: history of early-stage (I-III) breast cancer completed anthracycline-based chemotherapy 1-6 years earlier aged ≥60 years had a body mass index (BMI) >25 kg/m2 Exclusion Criteria: taking lipid, glucose, or weight-lowering medications contraindications to maximal exercise testing or research MRI unstable thyroid disorder self-reported history of an eating disorder self-reported diagnosis of type 1 or 2 diabetes weight loss of ≥15 lbs in previous 3 months working night shifts could not provide consent in English

Ages Eligible for Study
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Minimum Age: 60 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Weekday time-restricted eating<br>The intervention consisted of 8 weeks of ad libitum TRE with a 12-8 pm 8-hour eating window on weekdays. Participants received instructions to only consume water, black coffee, or black tea from 8 pm to 12 pm on weekdays and during the weekend, where there were no restrictions on eating timing. No other dietary or physical activity instructions were given. | Behavioral: Time-restricted eating<br>* Restriction of calorie intake to an 8-hour window, with water only fasting in the remaining 16 hours of the 24-hour period<br>* Other names: intermittent fasting;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Framingham 10-year cardiovascular risk score (%) | Calculated using the Canadian Cardiovascular scoring system | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visceral adipose tissue | measured via magnetic resonance fat-water separation imaging | 8 weeks | 
| Thigh adipose tissue fraction | Relative measure of amount of inter+intra muscular adipose tissue within the thigh muscle measured via magnetic resonance fat-water separation imaging | 8 weeks | 
| Liver adipose tissue fraction | Relative measure of amount of adipose tissue within the liver | 8 weeks | 
| Cardiorespiratory fitness | Measured as peak volume of oxygen consumed collected with a cycle erogmeter exercise test | 8 weeks | 
| Resting energy expenditure | Collected via metabolic cart in supine resting position after overnight fast | 8 weeks | 
| Respiratory quotient | Collected via metabolic cart in supine resting position after overnight fast | 8 weeks | 
| Lipid profile | Collected via analysis of fasting blood sample by Lifelabs commercial laboratory | 8 weeks | 
| Hemoglobin A1c | Collected via analysis of blood sample by Lifelabs commercial laboratory | 8 weeks | 
| Waist circumference | measured as the average of two measurements to the nearest 0.5 cm. | 8 weeks | 
| Fasting glucose | Collected via analysis of fasting blood sample by Lifelabs commercial laboratory | 8 weeks | 
| Fasting insulin | Collected via analysis of fasting blood sample by Lifelabs commercial laboratory | 8 weeks | 
| Resting systolic and diastolic blood pressure | measured as the average of two measurements 60 seconds apart following 5-10 minutes of supine rest using an automated device | 8 weeks | 
| Body mass | measured by physicians scale after overnight fast | 8 weeks | 
| Whole-body fat mass | estimated using8-point bioelectric impedance (Seca) | 8 weeks | 
| Whole-body fat-free mass | estimated using8-point bioelectric impedance (Seca) | 8 weeks |