Monitoring During Different Intermittent Fasting Protocols in Non-Obese Adults (LIMITFOOD)

Longitudinal Monitoring During Different Intermittent Fasting Protocols in Non-Obese Adults - A Randomized Clinical Trial

LIMITFOOD is a randomized clinical intervention study that investigates the effects of two different intermittent fasting protocols compared to a control group on the health of normal- and overweight adults. A total of 72 participants will be randomized into three equally sized groups: an alternate day fasting, a time-restricted feeding and a control group.

Study Overview

• Status: Completed
• Conditions: Overweight; Time Restricted Feeding; Intermittent Fasting
• Intervention / Treatment: Behavioral: Time-Restricted Feeding; Behavioral: Alternate Day Fasting

Detailed Description

The prevalence of overweight has risen considerably all over the world in the past century. Epidemiological studies have shown that, starting from a body mass index of 20-21 kg/m2, increasing BMI levels are associated with progressively increased risks of developing diabetes, cardiovascular disease, several types of cancer and other diseases. The problem is pronounced by the unlimited and constant availability of food. Treatment of overweight is still difficult and finding effective and more personalized strategies to manage these conditions is crucial.

Intermittent fasting has been suggested as an alternative way to address these problems. Intermittent fasting is an eating pattern that involves rotating periods of eating and fasting. Animal studies and previous human clinical trials have provided evidence that various types of intermittent fasting lead to weight loss and improved health markers not only in obese, but also in healthy, non-obese adults.There are several types of intermittent fasting. The most popular version is time-restricted feeding (TRF), which allows ad libitum (at one's pleasure) energy intake within a defined period of time each day (6-12h). Another subtype of IF is called alternate day fasting (ADF). ADF is defined as 'feast days' on which food is consumed ad libitum, which alternate with 'fast days' on which food is withheld or reduced.

However, despite the growing popularity of intermittent fasting, it is not clear which type of IF is most effective and what fasting window is needed to induce beneficial effects. Additionally, tools to longitudinally track personal progress of dieting are lacking. Therefore, the main objective of this study is to compare the effects of each of two different intermittent fasting protocols (TRF and ADF) on metabolic parameters to a control group. Furthermore, a new dynamic measurement technique, using breath analysis, will allow to better monitor the progress of individual participants.

• Study Type: Interventional
• Enrollment (Actual): 76
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Zürich, Switzerland, 8091
    • Department of Endocrinology, Diabetology and Clinical Nutrition

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 38 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age between 18-40 years, both inclusive
• Non-obese, BMI between 23 and 30 kg/m2, both inclusive
• Non-smoker
• Good knowledge of German or English language
• Stable weight change (change < +/- 10% current bodyweight) for 3 months prior to the study
• Glycohemoglobin (HbA1c) < 5.7% without glucose lowering medication
• LDL-cholesterol < 180 mg/dl without lipid lowering medication
• Blood pressure < 140/90 mmHG without blood pressure lowering medication

Exclusion Criteria:

• Subjects who have a fasting period of > 12h per day on a regular basis and do not eat at least three main meals per day.
• Current habitual use of dietary supplements (e.g. vitamins, minerals) and/or unwillingness to cease intake of dietary supplements.
• Antibiotics intake during 3 months prior to the study
• Food intolerances, allergies and sensitivities (e.g. lactose/gluten intolerance, food allergies) or dietary restrictions (e.g. vegan lifestyle)
• Acute or chronic infections, malignant disease, renal, hepatic (more than two-fold increased transaminases), pulmonary, neurological (epilepsy) or psychiatric diseases, manifested atherosclerosis, or any other disease precluding participation in the study.
• Diabetes
• Known alcohol, substance or drug abuse, concomitant medication
• More than four hours of physical exercise per week
• Women who are pregnant, breast-feeding or aiming to become pregnant during course of the trial
• Women and men on hormonal supplementation
• Women with a very irregular menstrual cycle
• Therapy with antidepressants within the past 6 months
• Regular therapy with acetylsalicyclic acid or current medication to regulate blood sugar, blood pressure or lipids
• Subjects likely to fail to comply with the study protocol
• Subjects who do not give informed consent

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
Active Comparator: Time-Restricted Feeding; Participants in the time-restricted feeding are instructed to eat ad libitum from 12:00 to 20:00 daily, and fast from 20:00 to 12:00 daily for 4 weeks.	Behavioral: Time-Restricted Feeding; Participants are instructed to limit food intake to maximum 8 hours per day.
Active Comparator: Alternate Day Fasting; Participants in the alternate day fasting group are instructed to eat every second day ad libitum, but to abstain from calorie intake on fast days (100 % restriction) for 4 weeks.	Behavioral: Alternate Day Fasting; Participants are instructed to fast every other day.
No Intervention: Control; Participants in the control group are instructed to maintain their habitual diet regimen.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fat mass	Change in whole body fat mass	4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Continuous glucose monitoring (CGM)	During the study period the CGM system will measure the continuous glucose concentration of the participants and thereby any changes will be measured.	4 weeks
Physical activity energy expenditure	Change in mean physical activity energy expenditure will be recorded using an Actiheart monitor during the intervention.	4 weeks
Resting metabolic rate (measured by indirect calorimetry)	Change in resting metabolic rate	4 weeks

Collaborators and Investigators

• Sponsor: Philipp Gerber
• Investigators: Principal Investigator: Philipp Gerber, MD, University of Zurich

Study record dates

Study Major Dates

• Study Start (Actual): March 10, 2021
• Primary Completion (Actual): July 1, 2023
• Study Completion (Actual): July 1, 2023

Study Registration Dates

• First Submitted: January 19, 2021
• First Submitted That Met QC Criteria: January 29, 2021
• First Posted (Actual): February 1, 2021

Study Record Updates

• Last Update Posted (Actual): October 6, 2023
• Last Update Submitted That Met QC Criteria: October 5, 2023
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Body Weight; Overweight
• Other Study ID Numbers: LIMITFOOD

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