Effects of Intermittent Fasting and Exercise on Inflammation, Metabolism, and the Microbiome in Metabolic Syndrome (FIT)

Effects of Intermittent Fasting and Its Combination with High-Intensity Interval Training on Inflammatory and Metabolic Markers, As Well As the Microbiome in Patients with Metabolic Syndrome: a Randomized Controlled Pilot Study

The goal of this intervention trial is to assess the effects of intermittent fasting, both alone and in combination with high-intensity interval training, on patients with obesity and metabolic syndrome. The main question it aims to answer is:

Does intermittent fasting, with or without high-intensity interval training, reduce chronic inflammation in patients with obesity and metabolic syndrome?

Participants will follow an intermittent fasting regime for 3 months, with one intervention group additionally participating in high-intensity interval training twice a week. In addition, there are two control groups: one consisting of participants with metabolic syndrome and one consisting of generally healthy individuals. The study includes a 3-month intervention phase followed by a 3-month follow-up phase. During the 6-month study period, all participants will attend 6 in-house study visits and 2 phone visits, during which they will undergo assessments and receive nutritional counseling.

Study Overview

• Status: Recruiting
• Conditions: Metabolic Syndrome; Obesity and Obesity-related Medical Conditions
• Intervention / Treatment: Other: Alternate day fasting; Other: Time restricted eating; Other: High-intensity interval training

• Study Type: Interventional
• Enrollment (Estimated): 250
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Prof. Dr. med. Yurdagül Zopf; Phone Number: 0049091318545220; Email: yurdaguel.zopf@uk-erlangen.de

Study Locations

• Germany
  • Bavaria
    • Erlangen, Bavaria, Germany, 91054
      • Recruiting
      • Hector-Center for Nutrition, Exercise and Sports, University Hospital Erlangen
      • Contact: Prof. Dr. med. Yurdagül Zopf; Phone Number: 0049091318545220; Email: hectorcenter.m1@uk-erlangen.de

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Written consent to participate in the study.
• Persons aged 18 years and older.
• Diagnosis of Metabolic Syndrome (MetS) with elevated hsCRP.

Exclusion Criteria:

• Pregnant or nursing individuals.
• Cardiovascular diseases or orthopedic restrictions that prevent exercise.
• Use of medication or supplements that significantly affect study outcomes (e.g., anti-inflammatory medications, antibiotics within the last 6 weeks).
• Body weight greater than 200 kg (maximum capacity of training equipment).
• Individuals with mental illnesses that may impair their ability to understand or participate in the study.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Metabolic syndrome - alternate day fasting; Patients with metabolic syndrome who undergo alternate-day fasting in addition to regular advice on the mediterranean diet	Other: Alternate day fasting; Participants are instructed to alternate between consuming 100% of their usual energy intake on one day and only 25% on the following day.
Experimental: Metabolic syndrome - time restricted eating; Patients with metabolic syndrome who undergo time restricted eating in addition to regular advice on the mediterranean diet	Other: Time restricted eating; Subjects are instructed to limit their energy intake to 8 hours a day and to fast for the remaining 16 hours.
Experimental: Metabolic syndrome - time restricted eating plus high-intensity interval training; Patients with metabolic syndrome who undergo time restricted eating plus high-intensity interval training in addition to regular advice on the mediterranean diet	Other: Time restricted eating; Subjects are instructed to limit their energy intake to 8 hours a day and to fast for the remaining 16 hours.; Other: High-intensity interval training; Patients participate in high-intensity interval training.
No Intervention: Metabolic syndrome - controls; Patients with metabolic syndrome exclusively receiving regular advice on the mediterranean diet
No Intervention: Healthy - controls; Healthy controls exclusively receiving regular advice on the mediterranean diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
hsCRP	High sensitivity C-reactive protein in mg/l.	From enrollment to the end of intervention at 3 months.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
inflammatory markers and metabolic markers	Determination of inflammatory markers and metabolic markers in blood (e.g., sICAM-1, IGF-1, β-hydroxybutyrate, estrogens, androgens).	From enrollment to the end of intervention at 3 months.
waist circumference	Measurement of waist circumference in centimeters (cm).	From enrollment to the end of intervention at 3 months.
fasting blood glucose	Measurement of fasting blood glucose in milligrams per deciliter (mg/dL).	From enrollment to the end of intervention at 3 months.
triglycerides	Measurement of triglycerides in milligrams per deciliter (mg/dL).	From enrollment to the end of intervention at 3 months.
cholesterol	Measurement of cholesterol (total, LDL, HDL) in milligrams per deciliter (mg/dL).	From enrollment to the end of intervention at 3 months.
blood pressure	Measurement of systolic and diastolic blood pressure in millimeters of mercury (mmHg).	From enrollment to the end of intervention at 3 months.
cardiometabolic risk profile	Calculation of the MetS z-score by combining waist circumference, fasting blood glucose, triglycerides, cholesterol, and blood pressure. The z-score will be reported as a single value based on these separate measures.	From enrollment to the end of intervention at 3 months.
maximal oxygen uptake	Measurement of maximal oxygen uptake (VO2max) via spiroergometry.	From enrollment to the end of intervention at 3 months.
liver fat status	Measurement of liver fat status via ultrasound examination.	From enrollment to the end of intervention at 3 months.
composition of the intestinal and oral microbiome	Determination of the composition of the intestinal and oral microbiome by sequencing bacterial 16sRNA on the MiSeq platform, as well as analysis of the stool metabolome.	From enrollment to the end of intervention at 3 months.
skin microbiome	Determination of the composition of the skin microbiome.	From enrollment to the end of intervention at 3 months.
cortisol	Detection of cortisol from 24-hour urine collection.	From enrollment to the end of intervention at 3 months.
body weight	Measurement of body weight in kilograms (kg) using bioimpedance analysis.	From enrollment to the end of intervention at 3 months.
body fat percentage	Measurement of body fat percentage (%) using bioimpedance analysis.	From enrollment to the end of intervention at 3 months.
fat-free mass	Measurement of fat-free mass (in kilograms) using bioimpedance analysis.	From enrollment to the end of intervention at 3 months.
muscle mass	Measurement of muscle mass (in kilograms) using bioimpedance analysis.	From enrollment to the end of intervention at 3 months.
phase angle	Measurement of phase angle (in degrees) using bioimpedance analysis.	From enrollment to the end of intervention at 3 months.

Collaborators and Investigators

• Sponsor: University of Erlangen-Nürnberg Medical School

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2023
• Primary Completion (Estimated): December 1, 2025
• Study Completion (Estimated): March 1, 2026

Study Registration Dates

• First Submitted: March 6, 2025
• First Submitted That Met QC Criteria: March 17, 2025
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: March 17, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: obesity; inflammation; intermittent fasting; metabolic syndrome; high-intensity interval training
• Additional Relevant MeSH Terms: Pathologic Processes; Nutrition Disorders; Metabolic Diseases; Overnutrition; Body Weight; Disease; Glucose Metabolism Disorders; Insulin Resistance; Hyperinsulinism; Overweight; Obesity; Syndrome; Metabolic Syndrome
• Other Study ID Numbers: 22-60_2-B

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No