The Effect of Flexitarian, Time-restricted Eating on Cardiometabolic Traits in Normal Weight, Young Men (FlexiFast)

The Effect of Flexitarian, Time-restricted Eating on Cardiometabolic Traits in Normal Weight, Young Men: a Factorial Randomized Controlled Trial (FlexiFast Study)

The goal of this factorial randomized controlled trial is to find out whether time-restricted eating and flexitarian diet (on its own and combined) can improve cardiometabolic health markers in normal weight, young men with metabolic abnormalities?

Participants will be assigned to four groups: control, flexitarian, time-restricted eating and time-restricted eating + flexitarian. Investigators will look for men with elevated fasting blood glucose or blood lipids level or blood pressure and with normal body weight and waistline. Participants from the flexitarian group will be asked to follow a diet that has been carefully designed for them by the PI and dietitian for the period of 8 weeks. Participants from the control group will receive general healthy eating recommendations.

We aim to investigate if the experiment had any effect on changes in metabolic, inflammation and nutritional markers, blood pressure and body weight and composition. Also, the effect of diets on men's sleep, general wellbeing and satisfaction with treatment will be investigated.

The proposed study can test a potentially effective nutritional intervention which is feasible to adopt and sustainable (in line with recent planetary diet recommendations). Confirming its effectiveness can fill the research gap, providing new knowledge and approach to the prevention and treatment of metabolic abnormalities in young, lean men.

Study Overview

• Status: Active, not recruiting
• Conditions: Glucose Metabolism Disorders; Lipid Metabolism Disorders; Blood Pressure; Cardiometabolic Syndrome
• Intervention / Treatment: Behavioral: Dietary

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

Contacts and Locations

Study Locations

• Poland
  • Olsztyn, Poland, 10-719
    • University of Warmia and Mazury in Olsztyn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 40 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Males
• Age 18-40 years
• Normal body weight
• At least one of metabolic abnormalities (elevated fasting glucose level - but not diabetes, elevated blood lipids, elevated blood pressure)

Exclusion Criteria:

• Females
• Age <18 and >40 years
• Overweight or obesity (BMI>25 kg/m2)
• WC > 94cm
• Alcohol >14 units/week
• Smoking
• On medication
• Diabetes or other chronic diseases
• Vegetarians or vegans
• Don't own or unable to use a Smartphone with Apple iOS or Android OS

Study Plan

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control group; Habitual diet - healthy eating guidelines provided for ethical reasons, no restrictions on the time of eating
Experimental: Flexitarian diet group; Flexitarian diet (FD) will be based on planetary diet recommendations (predominantly plants; pulses and legumes as protein sources, meat and poultry consumed occasionally). Ways to facilitate this diet will be presented in the booklet prepared for them by the PI and a dietitian.	Behavioral: Dietary; Depending on the allocation arm, participants will be advised to follow a particular dietary plan (either flexitarian eating, time-restricted eating or both combined).
Experimental: Time-restricted eating group; Time restricted eating (TRE) with 6 hour eating window - start and end hour to be an individual choice (some may prefer to consume their meals within an early window, e.g. 10am-4pm, some may prefer to consume their meals later in the day, e.g. 12:00-6pm). However, participants will be asked to be fairly consistent with their choice of their timing of eating hours. During fasting only water will be permitted;	Behavioral: Dietary; Depending on the allocation arm, participants will be advised to follow a particular dietary plan (either flexitarian eating, time-restricted eating or both combined).
Experimental: Flexitarian diet & time-restricted eating group; Treatment TRE and FD combined.	Behavioral: Dietary; Depending on the allocation arm, participants will be advised to follow a particular dietary plan (either flexitarian eating, time-restricted eating or both combined).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in glucose homeostasis	Change in fasting glucose concentration [mg/dL]. Blood samples will be collected after the overnight fast and the analysis will be performed on the Cobas Integra 400 plus analyzer.	baseline, after 8 weeks and after 20 weeks from baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in total cholesterol (TC)	The blood serum concentration of total cholesterol (in mmol/L). Blood samples will be collected after the overnight fast and the analysis will be performed on the Cobas Integra 400 plus analyzer.	baseline, after 8 weeks and after 20 weeks from baseline
Change in high-density lipoprotein (HDL) cholesterol	The blood serum concentration of high-density lipoprotein cholesterol (in mmol/L). Blood samples will be collected after the overnight fast and the analysis will be performed on the Cobas Integra 400 plus analyzer.	baseline, after 8 weeks and after 20 weeks from baseline
Change in low-density lipoprotein (LDL) cholesterol	The blood serum concentration of low-density lipoprotein cholesterol (in mmol/L). Blood samples will be collected after the overnight fast and the analysis will be performed on Cobas Integra 400 plus analyzer.	baseline, after 8 weeks and after 20 weeks from baseline
Change in serum triglycerides (TG)	The concentration of serum triglycerides (in mmol/L). Blood samples will be collected after the overnight fast and the analysis will be performed on Cobas Integra 400 plus analyzer.	baseline, after 8 weeks and after 20 weeks from baseline
Change in body weight	Body weight (in kg) will be measured using a digital medical scale witl stadiometer.	baseline, after 8 weeks and after 20 weeks from baseline
Change in body mass index (BMI)	The measured values of body height and weight will be used for the calculation of body mass index (in kg/m^2).	baseline, after 8 weeks and after 20 weeks from baseline
Change in body fat mass percentage	Determination of body fat percentage will be performed using SECA® mBCA 515 analyser	baseline, after 8 weeks and after 20 weeks from baseline
Change in waist circumference	Waist circumference measuring (in cm) will be performed using a non-strechable measuring tape.	baseline, after 8 weeks and after 20 weeks from baseline
Change in waist-to-hip ratio	The waist-to-hip ratio will be calculated from the measured values of waist and hip circumferences: waist circumference (cm) / hip circumference (cm).	baseline, after 8 weeks and after 20 weeks from baseline
Change in visceral adipose tissue (VAT)	Determination of abdominal fat volume will be measured in litres and performed using SECA® mBCA 515 analyser	baseline, after 8 weeks and after 20 weeks from baseline
Change in inflammatory markers-1	interleukin-6 [pg/mL] - COBAS e411 analyser	baseline, after 8 weeks and after 20 weeks from baseline
Change in inflammatory markers-2	C-reactive protein (CRP) [mg/L] - COBAS Integra 400 Plus analyser	baseline, after 8 weeks and after 20 weeks from baseline
Change in nutrition markers-1	Homocysteine [μmol/L] - COBAS Integra 400 Plus analyser	baseline, after 8 weeks and after 20 weeks from baseline
Change in nutrition markers-2	Vitamin B12 [pg/mL] - COBAS e411 analyser	baseline, after 8 weeks and after 20 weeks from baseline
Change in insulin concentration	Insulin [units/mL] - COBAS e411 analyser	baseline, after 8 weeks and after 20 weeks from baseline
Change in haemoglobin glycosylated (HbA1c) concentration	HbA1c [mmol/l] - COBAS e411 analyser	baseline, after 8 weeks and after 20 weeks from baseline
Change in systolic and diastolic blood pressure	The assessment of blood pressure (in mmHg) will be performed prior to and immediately after the intervention using electronic monitor (Omron M3 Intellisense Automatic Blood Monitor, Omron Healthcare, Mannheim, Germany).	baseline, after 8 weeks and after 20 weeks from baseline

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in sleep length	Measured using smartbands with sleep trackers: length (in hours)	baseline, after 8 weeks and after 20 weeks from baseline
Change in sleep quality	Measured using smartbands with sleep trackers: with metrics specific to the selected model (score).	baseline, after 8 weeks and after 20 weeks from baseline
Change in cardiorespiratory fitness	Oxygen consumption (VO2) measured using ergospirometer CORTEX MetaMax 3b (ml oxygen/kg of body weight/minute). VO2 max is the maximum amount of oxygen the body can utilize during exercise.	baseline, after 8 weeks and after 20 weeks from baseline
Change in physical activity level	Measured using smartbands with pedometers (number of daily steps)	baseline, after 8 weeks and after 20 weeks from baseline
Participant's satisfaction with treatment upon completion	Satisfaction with treatment: DSat-28 questionnaire (10.1002/osp4.299)	after 8 weeks
Change in dietary behaviours	Dietary habits will be assessed using KomPAN questionnaire (https://doi.org/10.3390/nu10121845)	baseline, after 8 weeks and after 20 weeks from baseline

Collaborators and Investigators

• Sponsor: University of Warmia and Mazury in Olsztyn
• Investigators: Principal Investigator: Marta Lonnie, MSc, University of Warmia and Mazury in Olsztyn

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2023
• Primary Completion (Estimated): December 1, 2023
• Study Completion (Estimated): December 1, 2023

Study Registration Dates

• First Submitted: December 21, 2022
• First Submitted That Met QC Criteria: March 7, 2023
• First Posted (Actual): March 9, 2023

Study Record Updates

• Last Update Posted (Actual): November 7, 2023
• Last Update Submitted That Met QC Criteria: November 6, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Insulin Resistance; Hyperinsulinism; Metabolic Syndrome; Metabolic Diseases; Lipid Metabolism Disorders; Glucose Metabolism Disorders
• Other Study ID Numbers: 2021/41/N/NZ9/01129

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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