Hypoxia, Appetite, and Energy Intake in Young Female Adults

Not Applicable

Recruiting

• Conditions: Hypoxia; Altitude; Appetite; Energy Intake

• Registration Number: NCT06912230
• Lead Sponsor: University of Ottawa

Brief Summary

The goal of this clinical trial is to investigate the effects of acute passive continuous hypoxemia (simulated high-altitude at rest) on appetite and energy intake in healthy young female adults. The main questions it aims to answer are:

* Does six hours of simulated high-altitude (5000 meters) reduce scores of subjective appetite and energy intake?

* Do changes in appetite and energy intake persist in the hours following the end of hypoxic exposure? Researchers will compare the effects of simulated high-altitude to a control normoxia (sea-level) condition to see if exposure to low oxygen levels independently affect appetite and energy intake.

Participants will:

* Visit the laboratory for a preliminary screening session to assess eligibility.

* Undergo two randomized, single-blind, experimental sessions consisting of six hours of passive exposure to normoxia or hypoxia in a climate-controlled chamber.

* Consume foods provided from a curated list, served in ad libitum quantities, after leaving the laboratory to assess post-exposure energy intake.

Detailed Description

Not available

Study Timeline

• Status Verified: 2024-10
• Study Start: 2024-11-13
• Study First Submitted: 2025-03-17
• Study First Submitted QC: 2025-03-28
• Last Update Submitted: 2025-03-28
• Study First Posted: 2025-04-04
• Last Update Posted: 2025-04-04
• Primary Completion: 2025-12
• Study Completion: 2025-12

Recruitment & Eligibility

• Status: RECRUITING
• Sex: Female
• Target Recruitment: 10

Inclusion Criteria

• English or French speaking
• Ability to provide informed consent

Exclusion Criteria

• History or evidence of chronic disease
• Current use of hypolipemic medication
• Current use of hormonal contraceptives
• Current use of antidepressants
• Current use of anticoagulants
• Ongoing smoking status
• Experiencing pregnancy, puerperium, or irregular menstrual cycles

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Change from baseline in desire to eat	Baseline and 6 hours; Baseline and 24 hours	Scores of subjective desire to eat, measured using visual analog scales. Measurements are performed upon arrival at the laboratory (baseline), hourly during the exposure, immediately after a 30-minute ad libitum buffet, immediately before bedtime, and 24 hours after the baseline measurement.
Change from baseline in prospective food consumption	Baseline and 6 hours; Baseline and 24 hours	Scores of subjective prospective food consumption, measured using visual analog scales. Measurements are performed upon arrival at the laboratory (baseline), hourly during the exposure, immediately after a 30-minute ad libitum buffet, immediately before bedtime, and 24 hours after the baseline measurement.
Energy intake immediately after 6 hours of exposure (buffet)	Hour 6 of exposure	Energy intake in the laboratory during a 30-minute ad libitum buffet immediately after 6 hours of exposure, administered using a validated food menu (McNeil, 2012) and analyzed using the Food Processor SQL from ESHA Research, Inc.
Energy intake post-buffet	6.5 hours of exposure and 24 hours	Energy intake outside the laboratory between end-buffet and bedtime, administered using a validated food menu (McNeil, 2012) and analyzed using the Food Processor SQL from ESHA Research, Inc.
Change from baseline in hunger	Baseline and 6 hours; Baseline and 24 hours	Scores of subjective hunger, measured using visual analog scales. Measurements are performed upon arrival at the laboratory (baseline), hourly during the exposure, immediately after a 30-minute ad libitum buffet, immediately before bedtime, and 24 hours after the baseline measurement.
Change from baseline in fullness	Baseline and 6 hours; Baseline and 24 hours	Scores of subjective fullness, measured using visual analog scales. Measurements are performed upon arrival at the laboratory (baseline), hourly during the exposure, immediately after a 30-minute ad libitum buffet, immediately before bedtime, and 24 hours after the baseline measurement.

Secondary Outcome Measures

Name	Time	Method
Change from baseline in explicit wanting using the LFPQ	Baseline and 6.5 hours of exposure	Explicit wanting will be measured using the Leeds Food Preference Questionnaire. Measurements will be taken upon arrival at the laboratory (baseline), following 5 hours of exposure, and after a 30-min ad libitum buffet.
Change from baseline in implicit wanting using the LFPQ	Baseline and 6.5 hours of exposure	Implicit wanting will be measured using the Leeds Food Preference Questionnaire. Measurements will be taken upon arrival at the laboratory (baseline), following 5 hours of exposure, and after a 30-min ad libitum buffet.
Heart rate	6 hours	Measured continuously throughout the exposure.
Oxyhemoglobin saturation	6 hours	Measured continuously throughout the exposure.
Systolic blood pressure	6 hours	Measured upon arrival at the laboratory (baseline), hourly during the exposure, and immediately after eating.
Diastolic blood pressure	6 hours	Measured upon arrival at the laboratory (baseline), hourly during the exposure, and immediately after eating.
Lake Louise Acute Mountain Sickness Score	6 hours	Peak score on the Lake Louise Acute Mountain Sickness questionnaire, measured upon arrival at the laboratory (baseline), hourly during the exposure, and immediately after eating.
Fluid consumption during exposure	6 hours	Average hourly fluid consumption calculated by weighing participant water intake at the start and end of each hour of exposure (normalized to the exposure duration).
Fluid loss during exposure	6 hours	Fluid loss calculated as the change in body mass during each exposure presented as a percentage of baseline body mass (corrected for fluid consumption)
Change from baseline in explicit liking using the LFPQ	Baseline and 6.5 hours of exposure	Explicit liking will be measured using the Leeds Food Preference Questionnaire. Measurements will be taken upon arrival at the laboratory (baseline), following 5 hours of exposure, and after a 30-min ad libitum buffet.
Change from baseline in olfaction	Baseline and Hour 4 of exposure	Olfaction will be measured using the Sniffin' Sticks (Burghart Instruments, Wedel, Germany), a 3-test battery of odorized markers that measure odor detection threshold, odor discrimination, and odor identification. Measurements will be performed upon arrival at the laboratory (baseline) and following 4 hours of exposure.
Change from baseline in gustation	Baseline and Hour 4 of exposure	Olfaction will be measured using Taste Strips (Burghart Instruments, Wedel, Germany). Measurements will be performed upon arrival at the laboratory (baseline) and following 4 hours of exposure.
Change from baseline in resting energy expenditure	Baseline and Hour 5 of exposure	Resting energy expenditure will be measured via indirect calorimetry upon arrival at the laboratory (baseline) and following 5 hours of exposure.
Change from baseline in respiratory exchange ratio	Baseline and Hour 5 of exposure	Respiratory exchange ratio will be measured via indirect calorimetry upon arrival at the laboratory (baseline) and following 5 hours of exposure.
Change from baseline in plasma glucose concentrations	6 hours	Plasma glucose concentrations will be measured via colorimetric assays from venous blood samples collected upon arrival at the laboratory (baseline) and hourly during the exposure (i.e., 0 or baseline, 60, 120, 180, 240, 300, and 360 minutes).
Change from baseline in plasma insulin concentrations	6 hours	Plasma insulin concentrations will be measured via colorimetric assays from venous blood samples collected upon arrival at the laboratory (baseline) and hourly during the exposure (i.e., 0 or baseline, 60, 120, 180, 240, 300, and 360 minutes).
Change from baseline in plasma non-esterified fatty acid concentrations	6 hours	Plasma non-esterified fatty acid concentrations will be measured via colorimetric assays from venous blood samples collected upon arrival at the laboratory (baseline) and hourly during the exposure (i.e., 0 or baseline, 60, 120, 180, 240, 300, and 360 minutes).
Change from baseline in plasma triglyceride concentrations	6 hours	Plasma triglyceride concentrations will be measured via colorimetric assays from venous blood samples collected upon arrival at the laboratory (baseline) and hourly during the exposure (i.e., 0 or baseline, 60, 120, 180, 240, 300, and 360 minutes).
Change from baseline in plasma beta-hydroxybutyrate concentrations	6 hours	Plasma beta-hydroxybutyrate concentrations will be measured via colorimetric assays from venous blood samples collected upon arrival at the laboratory (baseline) and hourly during the exposure (i.e., 0 or baseline, 60, 120, 180, 240, 300, and 360 minutes).

Trial Locations

Locations (1)

Behavioural and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa; 🇨🇦 Ottawa, Ontario, Canada