4:3 Intermittent Fasting Intervention in Adults With Breast Cancer and Overweight or Obesity

NCT06399276 | Active Not Recruiting DMC

• 2 other identifiers: 23-1546.ccR01CA258766
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 2

Brief Summary

This is a 3 month single arm pilot and feasibility study designed to examine the impact of an intermittent fasting lifestyle weight loss intervention on pre-specified clinical milestones (change in body weight, adherence to the fasting program, and moderate-to vigorous physical activity, MVPA) in adults with overweight and obesity and breast cancer after they have completed their cancer treatment. The investigators will also evaluate feasibility of recruitment and retention of study participants, safety of the intervention, and obtain feedback from participants to improve the program. Participants will receive a 3 month lifestyle weight loss program focusing on a 4:3 intermittent fasting paradigm (3 modified fast days per week) and support to increase physical activity to 150 minutes per week. Outcome measures will be assessed at the end of the 3 month intervention (primary endpoint) and after a 3 month weight maintenance follow up phase.

Conditions

Breast Cancer

Keywords

Overweight; Obese

Outcome Measures

Primary Outcomes (3)

• Body Weight

  Measured using digital scale accurate to =/-0.1 kg, in the morning in a fasted state

  3 months

• Adherence to 4:3 Intermittent Fasting Dietary Paradigm as Measured by Food Records

  Dietary energy intake assessed using written food records for 7 consecutive days

  3 months

• Physical Activity

  Moderate to Vigorous Physical Activity (MVPA) (min/wk) measured with the activPALv4 activity monitor for 7 consecutive days.

  3 months

Secondary Outcomes (2)

• Rate of Enrollment

  at recruitment

• Percent of Participants Completing Outcome Measures

  3 months

Study Arms (1)

Behavioral Weight Loss Focused on Intermittent Fasting

EXPERIMENTAL

3-month integrated behavioral weight loss intervention with a dietary focus on intermittent fasting.

Behavioral: Weight Loss

Interventions

Weight Loss BEHAVIORAL

Participants are instructed to perform a modified fast (\~500 kcal) on 3 days/week with ad libitum intake the other 4 days/week. Group-based behavioral support sessions will be held by an experienced Registered Dietician. Participants will attend BfitBwell exercise sessions in person and virtually to receive individualized support to progress to 150 min/wk of moderate-intensity physical activity

Behavioral Weight Loss Focused on Intermittent Fasting

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may not qualify if:

• Have a primary care provider (PCP) (or are willing to establish care with a PCP prior to study enrollment) to address medical issues which may arise during screening or study procedures/interventions.
• Obtain a signed medical clearance from their medical provider for participation in the 4:3 IMF dietary intervention and BfitBwell clinical exercise oncology program.
• Own or willing to purchase a smart phone or computer to join Zoom meetings, complete questionnaires, and access/download the True Coach virtual exercise coaching sessions.
• All interested individuals will complete a brief online eligibility screener through REDCap to confirm initial eligibility.
• Eastern Cooperative Oncology Group (ECOG) Performance Status 2 or higher.
• Actively undergoing chemotherapy, radiation, immunotherapy and/or targeted therapy (other than anti-endocrine therapy) or are within 1 month of completion of chemotherapy, radiation, immunotherapy and/or targeted therapy (other than anti-endocrine therapy) as of the target intervention start date. Exceptions to this 1-month timeframe can be made on a case-by-case basis at the discretion of the PI if patients are tolerating therapy without adverse effects and will have completed treatment prior to the intervention start date.
• Plans to relocate within the next 12 months.
• Plans for extended travel (\>2 weeks) within the next 12 months.
• Major surgery within the past 3 months (including mastectomy or breast reconstruction but not including lumpectomy or other minor surgeries) or planned major surgery (including mastectomy or breast reconstruction) during the timeframe of the 6 month study intervention and follow-up phases.
• For Females:
• Currently pregnant or lactating.
• Pregnant within the past 6 months.
• Planning to become pregnant in the next 12 months; sexually active women of childbearing potential may be enrolled if they have had a tubal ligation or use a reliable means of contraception.
• Recent (past 6 months) acute coronary event, unstable angina, coronary revascularization, stroke, pulmonary embolism, or hospitalization for heart failure or cardiac arrythmia.
• Symptoms suggestive of cardiovascular disease or unstable angina (e.g., chest pain, shortness of breath at rest or with mild exertion, lightheadedness, syncope).

Sponsors & Collaborators

• National Cancer Institute (NCI): collaborator
• University of Colorado, Denver: lead

Study Sites (2)

Anschutz Health and Wellness

Aurora, Colorado, 80045, United States

Location

University of Colorado Anschutz Medical Campus

Aurora, Colorado, 80045, United States

Location

MeSH Terms

Conditions

Breast Neoplasms; Overweight; Obesity

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Victoria Catenacci, MD

  University of Colorado, Denver

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: SUPPORTIVE CARE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 30, 2024
• First Posted: May 3, 2024
• Study Start: May 28, 2024
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): June 1, 2027
• Last Updated: December 17, 2025

Record last verified: 2025-12

Locations

US (2)