Feasibility and Metabolic Effects of a 5:2 Fasting Intervention in Women With Breast Cancer During Radiotherapy

The intervention consists of the adoption of a 5:2 intermittent fasting diet during radiotherapy of breast cancer patients. The aim of the study was to assess the feasibility of this intervention and its impact on body composition and selected metabolic blood parameters.

Study Overview

• Status: Completed
• Conditions: Breast Cancer
• Intervention / Treatment: Radiation: Curative radiotherapy; Behavioral: 5:2 intermittent fasting

Detailed Description

The 5:2 intermittent fasting (FAST) intervention consisted of two nonconsecutive days of fasting per week that could be chosen freely according to the patient's weekly schedule. The minimum amount of time to count as a fasting day was 24 hours, but patients were advised to aim for a complete fasting day including the nights before and after that day. On a fasting day, only water and unsweetened tea or coffee was allowed. However, given that fat is the macronutrient interfering the least with the metabolic adaptions to fasting, while carbohydrates disturb the most [26], patients were allowed to consume small amounts of bone broth/meat broth, coconut oil, butter/ghee or heavy cream as an "emergency plan", i.e., in case that they felt they needed some energy-containing foods to complete an initiated fasting day.

The primary study outcome was the feasibility of the FAST intervention and its effects on longitudinal body composition changes from baseline until the final week of radiotherapy (body mass, fat mass, fat-free mass, muscle mass, extracellular and total body water). Secondary endpoints were absolute changes in metabolic parameters, hormones, and overall quality of life scores in the FAST group. As a surrogate marker for insulin resistance, the triglyceride-glucose index (TyG) was calculated according to TyG=ln⁡(fasting triglycerides [mg/dl]×fasting glucose [mg/dl]/ 2).

• Study Type: Interventional
• Enrollment (Actual): 13
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Germany
  • Bavaria
    • Schweinfurt, Bavaria, Germany, 97421
      • Leopoldina Hospital Schweinfurt, Department of Radiotherapy and Radiation Oncology
    • Schweinfurt, Bavaria, Germany, 97421
      • Department of Radiotherapy and Radiation Oncology

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Non-metastasized breast cancer
• Indication for curative radiotherapy

Exclusion Criteria:

• metallic body parts that would interfere with electric bioimpedance (BIA) measurements
• difficulties with understanding the aims of the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: FAST; 5:2 intermittent fasting group	Radiation: Curative radiotherapy; Curative radiotherapy as indicated by the patient's disease and prescribed by the treating radiation oncologist; Behavioral: 5:2 intermittent fasting; Two nonconsecutive days of fasting per week that could be chosen freely according to the patient's weekly schedule.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Dropout rate in the FAST intervention group	Used to measure feasibility. The intervention is rated as feasible if dropout rate is <30%	Through study completion, an average of 5 weeks
Longitudinal changes in body mass	Body mass (in kg) is measured by a bioimpedance device with an integrated scale (seca mBCA, seca Deutschland, Hamburg, Germany).	Through study completion, an average of 5 weeks
Longitudinal changes in fat-free mass	Fat-free mass (in kg) is estimated by a bioimpedance device with an integrated scale (seca mBCA, seca Deutschland, Hamburg, Germany).	Through study completion, an average of 5 weeks
Longitudinal changes in skeletal muscle mass	Skeletal muscle mass (in kg) is estimated by a bioimpedance device with an integrated scale (seca mBCA, seca Deutschland, Hamburg, Germany).	Through study completion, an average of 5 weeks
Longitudinal changes in total body water	Total body water content (in L) is estimated by a bioimpedance device with an integrated scale (seca mBCA, seca Deutschland, Hamburg, Germany).	Through study completion, an average of 5 weeks
Longitudinal changes in extracellular water	Extracellular water (in L) is estimated by a bioimpedance device with an integrated scale (seca mBCA, seca Deutschland, Hamburg, Germany).	Through study completion, an average of 5 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change between baseline and final (average 5 weeks) TyG index	As a surrogate marker for insulin resistance, the triglyceride-glucose index (TyG) is calculated according to TyG=ln⁡(fasting triglycerides [mg/dl]×fasting glucose [mg/dl]/ 2)	Through study completion, an average of 5 weeks

Collaborators and Investigators

• Sponsor: MVZ Leopoldina GmbH
• Investigators: Principal Investigator: Rainer J Klement, Ph.D., Department of Radiation Oncology, Leopoldina Hospital Schweinfurt

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2022
• Primary Completion (Actual): November 17, 2022
• Study Completion (Actual): November 17, 2022

Study Registration Dates

• First Submitted: May 2, 2023
• First Submitted That Met QC Criteria: May 12, 2023
• First Posted (Actual): May 16, 2023

Study Record Updates

• Last Update Posted (Actual): May 16, 2023
• Last Update Submitted That Met QC Criteria: May 12, 2023
• Last Verified: May 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Skin Diseases; Neoplasms; Neoplasms by Site; Breast Diseases; Breast Neoplasms
• Other Study ID Numbers: 2022-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Data will be made available upon reasonable request

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No