Breast Cancer
Conditions
Brief summary
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.
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).
Interventions
RADIATIONCurative radiotherapy
Curative radiotherapy as indicated by the patient's disease and prescribed by the treating radiation oncologist
BEHAVIORAL5:2 intermittent fasting
Two nonconsecutive days of fasting per week that could be chosen freely according to the patient's weekly schedule.
Sponsors
MVZ Leopoldina GmbH
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 75 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Longitudinal changes in fat-free mass | Through study completion, an average of 5 weeks | Fat-free mass (in kg) is estimated by a bioimpedance device with an integrated scale (seca mBCA, seca Deutschland, Hamburg, Germany). |
| Dropout rate in the FAST intervention group | Through study completion, an average of 5 weeks | Used to measure feasibility. The intervention is rated as feasible if dropout rate is \<30% |
| Longitudinal changes in body mass | Through study completion, an average of 5 weeks | Body mass (in kg) is measured by a bioimpedance device with an integrated scale (seca mBCA, seca Deutschland, Hamburg, Germany). |
| Longitudinal changes in extracellular water | Through study completion, an average of 5 weeks | Extracellular water (in L) is estimated by a bioimpedance device with an integrated scale (seca mBCA, seca Deutschland, Hamburg, Germany). |
| Longitudinal changes in skeletal muscle mass | Through study completion, an average of 5 weeks | Skeletal muscle mass (in kg) is estimated by a bioimpedance device with an integrated scale (seca mBCA, seca Deutschland, Hamburg, Germany). |
| Longitudinal changes in total body water | Through study completion, an average of 5 weeks | Total body water content (in L) is estimated by a bioimpedance device with an integrated scale (seca mBCA, seca Deutschland, Hamburg, Germany). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change between baseline and final (average 5 weeks) TyG index | Through study completion, an average of 5 weeks | 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) |
Countries
Germany
Outcome results
None listed