Intermittent Fasting Interventions on Brain Health in Women

Comparison of Intermittent Fasting Interventions on Brain Health in Women: A Randomized Controlled Trial

Adults experience high psychological stress due to many factors such as school, workplace, or personal life. Adult women are known to experience higher stress levels than men. Current evidence shows that fasting improves mental health outcomes in men. The research is unclear on fasting interventions and their potential impact on stress levels in women. In this study, investigators will compare two fasting diets over 8 weeks. There will be a control group, one group that fasts for two days per week, and a final group that only eats for 8 hours in the morning. Mental health surveys, brain tests and a blood draw will be done during the study to see any mental or physical changes from the diets. Investigators will study the motivation of women to continue the diet during and beyond the study through online surveys.

Study Overview

• Status: Enrolling by invitation
• Conditions: Psychological Stress
• Intervention / Treatment: Other: 5:2 Fasting; Other: Time Restricted Feeding

• Study Type: Interventional
• Enrollment (Estimated): 96
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jennifer J Heisz, PhD; Phone Number: 21944 9055259140; Email: heiszjj@mcmaster.ca

Study Locations

• Canada
  • Ontario
    • Hamilton, Ontario, Canada, L8S 4L8
      • McMaster University
      • Contact: Jennifer J Heisz, PhD; Phone Number: 21944 9055259140; Email: heiszjj@mcmaster.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 30 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• English speaker
• Assignment of female sex at birth
• BMI between 18.5-24.9 kg/m^2
• Current engagement in less than 150 minutes of physical activity per week
• Normal menstrual cycle length (21-40 days) for at least 3 months
• Non-smoker
• Consumption of no more than one alcoholic beverage per day
• Mild to higher levels of stress as indicated by a score of 15 or higher on the stress sub-set of the DASS-21 questionnaire

Exclusion criteria:

• Pregnant or breastfeeding
• Diagnosed chronic disease (cardiovascular, metabolic, respiratory, reproductive, renal, neuromuscular, or any other disease or condition as assessed by the Canadian Society for Exercise Physiology Get Active Questionnaire)
• Diagnosed eating disorder
• Participation in a weight-loss program in the last 3 months
• Loss of 5% of body weight or more in the last 3 months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 5:2 Fasting Group; This group will use the 5:2 method and fast for two non-consecutive days of the week.	Other: 5:2 Fasting; This group will use the 5:2 method and fast for two non-consecutive days of the week.; Other Names: 5:2 Method
Experimental: Time-Restricted Feeding Group; This group will use the 16:8 method every day, eating only during an 8-hour period that will commence at wake-up time.	Other: Time Restricted Feeding; This group will use the 16:8 method every day, eating only during an 8-hour period that will commence at wake-up time.; Other Names: TRF
No Intervention: Control Group; This group will not fast.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Depression, Anxiety and Stress Scale (DASS-21) Questionnaire - Stress Sub-Scale	Investigators will administer the standardized DASS-21 Questionnaire at Week 0 and Week 8. The stress sub-scale will be used to measure any potential effects of fasting interventions on psychological stress over time. The scoring of answers is based on a 0 to 3 scale. 3 reflects the negative extreme on the Likert Scale. Scores range from 0-42, higher scores are indicative of higher psychological stress levels.	8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mnemonic Similarity Task (MST)	Investigators will administer the standardized MST to assess the potential effects of fasting interventions on high interference memory over time. Several outcome measures will be produced: Reaction time; High-interference memory (assessed as the ability to correctly identify lure items as ''Similar''); General recognition memory performance (assessed as the ability to correctly identify repetitions items as ''Old'')	8 weeks
Pittsburgh Sleep Quality Index (PSQI)	Investigators will administer the standardized PSQI at Week 0 and Week 8 to measure the self-reported quality and patterns of sleep in adults. Several outcomes will be measured: Subjective sleep quality; Sleep latency; Sleep duration; Habitual sleep efficiency; Sleep disturbances; Use of sleeping medication; Daytime dysfunction over the last month The scoring of answers is based on a 0 to 3 scale. 3 reflects the negative extreme on the Likert Scale. Scores range from 0-21, where higher scores are indicative of poorer sleep quality and a global score of >5 is indicative of poor sleep quality.	8 weeks
Eating Disorder Examination Questionnaire (EDE-Q 6.0)	Investigators will administer the standardized EDEQ-6.0 during screening and Week 8 to measure self-reported disordered eating patterns in adults and the potential effects of fasting interventions on this outcome measure over time. 2 main outcomes will be measured: Frequency data on key behavioural features of eating disorders in terms of the number of episodes of the behaviour.; Sub-scale scores reflect the severity of characteristics of eating disorders. The sub-scales are Restraint, Eating Concern, Shape Concern and Weight Concern. Generally, sub scales are measures on a 7-point Likert scale. Higher scores on the global scale and sub-scales denote more problematic eating behaviours and attitudes.	8 weeks
Profile of Mood States (POMS)	Investigators will administer the standardized POMS at Week 0 and Week 8 to measure the potential effects of fasting interventions on self-reported quality and patterns of sleep in adults over time. Several outcomes will be measured: Total Mood Disturbance [TMD] (-32 to 200)Subscales:; Anger (0-48); Confusion (0-28); Depression (0-60); Fatigue (0-28); Tension (0-36); Vigour (0-32) The scoring of answers is based on a 5-point Likert scale (not at all - extremely). Higher TMD scores are indicative of a poorer mood state.	8 weeks
State Anxiety Inventory (STAI) Short Form	Investigators will administer the standardized STAI at Week 0 and Week 8 to measure the potential effects of fasting interventions on self-reported state and trait anxiety levels over time. All items are rated on a 4-point Likert scale (e.g., from "Almost Never" to "Almost Always"), with higher scores indicating greater anxiety levels.	8 weeks
Blood Pressure	Investigators will use an automated sphygmomanometer to measure blood pressure during each of the 2 in-lab sessions. Several measures will be collected: MAP (mmHg); Systolic pressure (mmHg); Diastolic pressure (mmHg)	8 weeks
Height (cm)	Investigators will use a vertical scale via measuring tape to measure height (cm) during each of the 2 in-lab sessions.	8 weeks
Weight (kg)	Investigators will use an automated scale to measure weight (kg) during each of the 2 in-lab sessions.	8 weeks
Waist Circumference (cm)	Investigators will use a flexible measuring tape to measure waist circumference (cm) during each of the 2 in-lab sessions.	8 weeks
Inflammatory Biomarker Interleukin-6 [IL6] (pg/mL)	A trained researcher who has completed phlebotomy course will take ~8 ml of blood will be drawn from an antecubital (forearm) vein at rest. The blood will be used to measure biomarkers of inflammation (e.g., proinflammatory cytokines IL6, TNF-a, CRP) during 2 in-lab sessions at week 0 and week 8. Measures will be recorded in pg/mL. A higher value will indicate higher levels of inflammation.	8 weeks
Inflammatory Biomarker Tumour Necrosis Factor Alpha [TNF-a] (pg/mL)	A trained researcher who has completed a phlebotomy course will take ~8 ml of blood will be drawn from an antecubital (forearm) vein at rest. The blood will be used to measure biomarkers of inflammation (e.g., proinflammatory cytokines IL6, TNF-a, CRP) during 2 in-lab sessions at week 0 and week 8. Measures will be recorded in pg/mL. A higher value will indicate higher levels of inflammation.	8 weeks
Inflammatory Biomarker C-Reactive Protein [CRP] (mg/L)	A trained researcher who has completed a phlebotomy course will take ~8 ml of blood will be drawn from an antecubital (forearm) vein at rest. The blood will be used to measure biomarkers of inflammation (e.g., proinflammatory cytokines IL6, TNF-a, CRP) during 2 in-lab sessions at week 0 and week 8. Measures will be recorded in mg/L. A higher value will indicate higher levels of inflammation.	8 weeks
Blood Ketone Levels (mmol/L)	Participants will perform finger pricks using a lancing device and measure blood ketone levels using a ketometer. Values will be recorded in mmol/L, with higher values indicating higher levels of circulating blood ketones.	8 weeks
Blood Glucose Levels (mmol/L)	Participants will perform finger pricks using a lancing device and measure blood ketone levels using a glucometer. Values will be recorded in mmol/L, with higher values indicating higher levels of circulating blood glucose.	8 weeks
Body Composition (% Body Fat)	Body composition (% body fat and lean body mass) will be measured in participants by investigators using a DEXA (DXA) scanner during the 2 in-lab sessions at Week 0 and Week 8. Higher percentages indicate a higher percent body fat and lower relative lean body mass.	8 weeks
Body Composition (Lean Body Mass - kg)	Body composition (% body fat and lean body mass) will be measured in participants by investigators using a DEXA (DXA) scanner during the 2 in-lab sessions at Week 0 and Week 8. Measures will be recorded in kg. A higher lean body mass indicates a lower relative body fat percentage.	8 weeks
Body Mass Index (BMI)	Body Mass Index will use participant height and weight as input values to produce a measure in kg/m^2 at Week 0 and Week 8. A higher BMI score indicates a relatively higher body fat percentage.	8 weeks
Diet Satisfaction & Adherence Questionnaire	Investigators will administer standardized questions taken from the Diet Satisfaction Questionnaire in addition to adherence questions to measure weekly dietary satisfaction and adherence to the fasting interventions during the intervention. Scoring is qualitative.	8 weeks
Colour and Word Stroop Test (SCWT)	Investigators will administer the standardized SCWT at Week 0 and Week 8 to assess the potential effects of fasting interventions on selective attention and response inhibition in participants over time. This task requires participants to name the displayed colour of the presented words while they disregard the meaning of the words. Several outcome measures will be produced: Reaction time (RT) in milliseconds (ms); The Stroop Effect - the difference in RT between incongruent and congruent trials, which can be broken down into 2 components:Stroop interference effect - the RT difference between incongruent and neutral trialsStroop facilitation effect - the RT difference between the neutral and congruent trials	8 weeks
Five Facet Mindfulness Questionnaire (FFMQ)	Investigators will administer the standardized FFMQ at Week 0 and Week 8 to measure the potential effects of fasting interventions on the self-reported trait-like tendency to be mindful in daily life. It is comprised of the following five related facets: observing, describing, acting with awareness, non-judging, and non-reactivity. The 39 items of the FFMQ are rated on a 5-point Likert scale: ranging from 1 (never or very rarely true) to 5 (very often or always true). Facet scores can also be combined to produce an overall mindfulness score. A higher score indicates a greater trait-like tendency to be mindful in daily life.	8 weeks
Pregnancy Status	Investigators will collect a urine sample and test it to determine the pregnancy status of the participant as per the exclusion criteria. A test strip will be placed in the urine. A positive pregnancy status will be indicated by the appearance of 2 lines in their respective locations on the strip. A negative pregnancy status will be indicated by the presence of only one line in its respective location on the strip.	One time measure at Week 0

Collaborators and Investigators

• Sponsor: McMaster University
• Collaborators: Natural Sciences and Engineering Research Council, Canada
• Investigators: Principal Investigator: Jennifer J Heisz, PhD, McMaster University

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2023
• Primary Completion (Estimated): May 1, 2024
• Study Completion (Estimated): May 1, 2024

Study Registration Dates

• First Submitted: November 8, 2022
• First Submitted That Met QC Criteria: November 16, 2022
• First Posted (Actual): November 29, 2022

Study Record Updates

• Last Update Posted (Actual): July 19, 2023
• Last Update Submitted That Met QC Criteria: July 18, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Behavioral Symptoms; Stress, Psychological
• Other Study ID Numbers: 14969

Drug and device information, study documents

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