Mechanisms of Fasting Induced Reduction in Energy Expenditure

Not Applicable

Recruiting

• Conditions: Fasting
• Interventions: Other: mixed meal test

• Registration Number: NCT06134258
• Lead Sponsor: ETH Zurich

Brief Summary

Fasting reduces the energy consumption of the human body. The extent of this adaptation varies significantly between different individuals. The aim of this research project is to investigate how this adaptation of the metabolism is regulated by the body. For this purpose, we will first measure how the so-called basal metabolic rate of the body reacts to a short-term fasting of 24 h in a preliminary study. Those subjects with a particularly pronounced and those subjects with an only slightly pronounced reaction of the basal metabolic rate will be invited to the main study.

Here, in random order (24 h fasting vs. 8 h fasting), the following is compared

* how the basal metabolic rate of the body reacts to the reduced energy intake.

* how the energy metabolism increases after a test meal

* what role in particular the thyroid hormones play in this adaptation. In addition, a sample of the subcutaneous adipose tissue is taken in each case and it is examined how the regulation of metabolic processes at the cellular level.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2023-11-06
• Study First Submitted QC: 2023-11-10
• Study Start: 2023-11-15
• Study First Posted: 2023-11-18
• Status Verified: 2023-12
• Last Update Submitted: 2023-12-07
• Last Update Posted: 2023-12-08
• Primary Completion: 2024-12
• Study Completion: 2024-12

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 40

Inclusion Criteria

• Age: 18 to 40 years
• Body mass index 18.0 to 27.0 kg/m²

Exclusion Criteria

• Chronic conditions necessitating medical treatment (e.g., renal failure, hepatic dysfunction, cardiovascular disease, diabetes mellitus),
• Known or suspected non-compliance, drug or alcohol abuse,
• Inability to follow the procedures of the study
• Participation in another study with investigational drug within the 30 days preceding and during the present study,
• Previous enrolment into the current study,
• Enrolment of the investigator, his/her family members, employees and other dependent persons,
• Hypothyroidism or hyperthyroidism
• Pregnant, breastfeeding and menopausal women

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Fasting for 24 hours	mixed meal test	-
Fasting for 8 hours	mixed meal test	-

Primary Outcome Measures

Name	Time	Method
change of energy expenditure (EE) determined by indirect calorimetry (kcal per 24h)	60 minutes after ingestion of test meal	Difference of EE (determined by indirect calorimetry) between baseline and 60 minutes after ingestion of the liquid test meal. Both measurements will be performed after an overnight fasting period.

Secondary Outcome Measures

Name	Time	Method
Level of free thyroxine	after 24 hours and after 12 hours of fasting	The thyroid hormone (TH) system is an important regulator of EE. We hypothesize that levels of TH are higher in the "spendthrift" than in the "thrifty" group.
Level of free triiodothyronine	after 24 hours and after 12 hours of fasting	The thyroid hormone (TH) system is an important regulator of EE. We hypothesize that levels of TH are higher in the "spendthrift" than in the "thrifty" group.
Respiratory quotient (RQ)	after 24 hours and after 12 hours of fasting	We hypothesize that the participants in the "thrifty" group have a lower proportion of fatty acid metabolism and therefore a higher RQ.

Trial Locations

Locations (1)

University Hospital Basel; 🇨🇭 Basel, Switzerland