Resting Metabolic RateNCT04151927
Effects of Overnight Low Oxygen Exposure on Energy Balance
A study testing Normobaric Hypoxia and Normobaric Normoxia in people with Resting Metabolic Rate and Appetite, run by Florida State University at 1 site in United States.
Trial summary
This research study will evaluate changes in resting metabolic rate, appetite, and heart rate variability following overnight exposure (8 h/night) to normobaric hypoxia (NH) or normobaric normoxic (NN). Read more about this study
- Who is it for?
- Ages 20 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Resting Metabolic Rate, Appetite, Heart Rate Variability
- What is being tested?
- Normobaric Hypoxia and Normobaric Normoxia
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 11 Dec 2019to 2 Oct 2021
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Men and women aged 20 - 45 years
- Body mass index between 18.5 - 24.5 kg/m2
- Born at altitudes less than 2,100 meters (~7,000 feet)
- Currently residing in Tallahassee, Florida or the surrounding area
- Not taking any medication(s) that interfere with metabolism or oxygen delivery/transport for four weeks before and throughout the entire study (e.g., includes sedatives, sleeping aids, tranquilizers, and/or any medication that depresses ventilation, diuretics, alpha, and beta-blockers).
- Willing to refrain from smoking, vaping, chewing tobacco, and dietary supplement use throughout the entire study
- Willing to spend two overnight visits on the Florida State University campus.
Who cannot join
- Living in areas that are more than 1,200 m (~4,000 feet), or have traveled to areas that are more than 1,200 m for five days or more within the last two months
- Metabolic or cardiovascular abnormalities, gastrointestinal disorders, or any condition that interferes with metabolism or oxygen delivery/transport (e.g., kidney disease, diabetes, cardiovascular disease, etc.)
- Prior diagnosis of apnea or other sleeping disorders
- Prior diagnosis of high-altitude pulmonary edema or high-altitude cerebral edema
- Prior diagnosis of anemia or sickle cell anemia/trait
- Present condition of alcoholism, anabolic steroid, or other substance abuse issues
- Women who are pregnant, lactating, planning to become pregnant, or who have had an irregular menstrual cycle in the past six months.
- Allergies or intolerance to foods included in the standardized or ad libitum meal (e.g., lactose intolerance/milk allergy)
Trial locations and contacts
1 site in 1 country.
United States1 site
Florida State University
Tallahassee, Florida, 32306
About this study
Official title: Effects of an Overnight, 8-hour Low Oxygen Exposure on Resting Energy Expenditure and Appetite: a Pilot Study
This research study will evaluate changes in resting metabolic rate, appetite, and heart rate variability following overnight exposure (8 h/night) to normobaric hypoxia (NH) or normobaric normoxic (NN). In randomized order, participants will sleep one night in NH conditions (~15% oxygen; achieved with nitrogen dilution, equivalent to ~8500 feet elevation) and another night in NN (control) conditions (~20% oxygen; achieved with nitrogen dilution, equivalent to ~1000 feet elevation).
Read the detailed description
Weight loss is a common factor reported in lowlanders traveling to high altitudes. Although the exact cause is unknown, studies have shown that weight loss at high altitude is associated with the amount of time and severity of the altitude exposure. Upon arrival to high altitude (≥ 5000 feet), numerous physiological adaptations occur that may promote weight loss, such as increased energy expenditure and reduced appetite. The breadth of current altitude research is limited by the logistical and monetary constraints of traveling to remote locations or access to an altitude chamber. A more logistically feasible alternative is the simulation of low oxygen conditions at sea level, using a commercially available tent and generator system to reduce ambient oxygen concentrations. The current research study will evaluate changes in resting metabolic rate, appetite, and heart rate variability following overnight exposure (8 h/night) to normobaric hypoxia (NH) or normobaric normoxic (NN). In randomized order, participants will sleep one night in NH conditions (~15% oxygen; achieved with nitrogen dilution, equivalent to ~8500 feet elevation) and another night in NN (control) conditions (~20% oxygen; achieved with nitrogen dilution, equivalent to ~1000 feet elevation). In the morning, following NH or NN exposure, resting metabolic rate will be measured using indirect calorimetry, appetite using an ad libitum buffet meal protocol, and heart rate variability by electrocardiogram. It is hypothesized that exposure to overnight NH will result in increased resting metabolic rate, decreased appetite, and decreased heart rate variability.
- Conditions
- Resting Metabolic Rate, Appetite, Heart Rate Variability
- Being tested
- Normobaric Hypoxia, Normobaric Normoxia
- Keywords
- High altitude, Metabolic adaptations, Energy balance
- Medical subject headings
- Altitude Sickness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Normobaric HypoxiaDevice
Low oxygen exposure to mimic ~8500 feet elevation.
Normobaric NormoxiaDevice
Normal oxygen exposure to mimic ~1000 feet elevation (sham comparator).
| Study group | Role | What they receive |
|---|---|---|
| Normobaric Hypoxia (NH) | Experimental | Overnight exposure (8 hours) to NH conditions (~15% oxygen; achieved with nitrogen dilution, equivalent to ~8500 feet elevation) using a commercially available tent and generator system (Hypoxico, Inc., New York, NY). Receives: Device: Normobaric Hypoxia; Device: Normobaric Normoxia |
| Normobaric Normoxia (NN) | Sham comparator | Overnight exposure (8 hours) to NN conditions (~20% oxygen; achieved with nitrogen dilution, equivalent to ~1000 feet elevation) using a commercially available tent and generator system (Hypoxico, Inc., New York, NY). Receives: Device: Normobaric Hypoxia; Device: Normobaric Normoxia |
What is being measured
The primary outcome is the main question the study is designed to answer.
Resting metabolic rate (kcal/d) following exposure to NH or NN conditions
Resting metabolic rate will be accessed using indirect calorimetry (TrueOne 2400, Parvo Medics, Salt Lake City, UT) following 8 hours of overnight exposure to NH or NN.
Measured: 8 hours
Secondary outcomes (13)
Objective appetite following exposure to NH or NN conditions
Objective appetite will be assessed by measuring total energy intake during an ad libitum buffet-style meal provided to participants following 8 hours of overnight exposure to NH or NN.
Measured: 8 hours
Food preferences following exposure to NH or NN conditions
Food preferences will be assessed by measuring macronutrient intake during an ad libitum buffet-style meal provided to participants following 8 hours of overnight exposure to NH or NN.
Measured: 8 hours
Fasting and postprandial hunger following exposure to NH or NN conditions
Measures will be assessed before and after the ad-libitum buffet meal using visual analog scales following 8 hours of overnight exposure to NH or NN.
Measured: Hunger will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Fasting and postprandial satiety following exposure to NH or NN conditions
Measures will be assessed before and after the ad-libitum buffet meal using visual analog scales following 8 hours of overnight exposure to NH or NN.
Measured: Satiety will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Fasting and postprandial prospective food consumption following exposure to NH or NN conditions
Measures will be assessed before and after the ad-libitum buffet meal using visual analog scales following 8 hours of overnight exposure to NH or NN.
Measured: Prospective food consumption will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Fasting and postprandial subjective appetite following exposure to NH or NN conditions
Measures will be assessed before and after the ad-libitum buffet meal using visual analog scales following 8 hours of overnight exposure to NH or NN.
Measured: Subjective appetite will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Energy intake following exposure to NH or NN conditions
Energy intake will be accessed using the Automated Self-Administered 24-Hour (ASA24®) Dietary Assessment Tool to complete dietary records for 2 days following 8 hours of overnight exposure to NH or NN.
Measured: 8 hours
Macronutrient intake following exposure to NH or NN conditions
Macronutrient intake will be accessed using the Automated Self-Administered 24-Hour (ASA24®) Dietary Assessment Tool to complete dietary records for 2 days following 8 hours of overnight exposure to NH or NN.
Measured: 8 hours
Heart rate variability following exposure to NH or NN conditions
Heart rate variability will be measured using a 3-lead electrocardiogram following 8 hours of overnight exposure to NH or NN.
Measured: 8 hours
Prevalence of acute mountain sickness following exposure to NH or NN conditions
Prevalence of acute mountain sickness will be accessed using the Environmental Symptoms Questionnaire following 8 hours of overnight exposure to NH or NN.
Measured: 8 hours
Severity of acute mountain sickness following exposure to NH or NN conditions
Severity of acute mountain sickness will be accessed using the Environmental Symptoms Questionnaire following 8 hours of overnight exposure to NH or NN.
Measured: 8 hours
Continuous oxygen saturation during exposure to NH or NN
Oxygen saturation will be measured continuously using a finger pulse oximeter (PalmSAT® 2500, Nonin Medical, Inc., Plymouth, MN) during 8 hours of overnight exposure to NH or NN.
Measured: 8 hours
Sleep quality following exposure to NH or NN conditions
Sleep quality will be measured by the Pittsburgh Sleep Quality Index following 8 hours of overnight exposure to NH or NN.
Measured: 8 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Nov 2019
- Study start11 Dec 2019
- Primary completion2 Oct 2021
- Study completion2 Oct 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Resting Metabolic RateStudies of the same condition, open and under way.
- More trials run by Florida State UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Florida State University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Claire E. Berryman, Florida State University
- Investigators
- Claire E Berryman, Ph.D., Principal investigator, Department of Nutrition, Food, and Exercise Science at Florida State University.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04151927
- Sponsor's protocol ID
- STUDY00000184
- Status last verified
- Nov 2021
- First submitted
- 26 Oct 2019
- Last updated
- 29 Nov 2021
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Baker PA, Long AN, Dawson MA, Berryman CE. An Overnight, 8-Hour Low Oxygen Exposure Increases Energy Expenditure with No Effect on Energy Intake: A Randomized, Sham-Controlled, Crossover Study. J Nutr. 2026 Mar;156(3):101319. doi: 10.1016/j.tjnut.2025.101319. Epub 2026 Jan 5.
PubMed 41500361
Study at a glance
From the registry record, last updated by the sponsor on 29 Nov 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of an Overnight, 8-hour Low Oxygen Exposure on Resting Energy Expenditure and Appetite: a Pilot Study
- ClinicalTrials.gov ID
- NCT04151927
- Acronym / sponsor ID
- STUDY00000184
- Conditions
- Resting Metabolic Rate, Appetite, Heart Rate Variability
- Keywords
- High altitude, Metabolic adaptations, Energy balance
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Florida State UniversityUniversity, hospital or other
- Study start
- 11 Dec 2019 (actual)
- Primary completion
- 2 Oct 2021 (actual)
- Study completion
- 2 Oct 2021 (actual)
- First posted
- 5 Nov 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This research study will evaluate changes in resting metabolic rate, appetite, and heart rate variability following overnight exposure (8 h/night) to normobaric hypoxia (NH) or normobaric normoxic (NN). In randomized order, participants will sleep one night in NH conditions (~15% oxygen; achieved with nitrogen dilution, equivalent to ~8500 feet elevation) and another night in NN (control) conditions (~20% oxygen; achieved with nitrogen dilution, equivalent to ~1000 feet elevation).
Detailed description
Weight loss is a common factor reported in lowlanders traveling to high altitudes. Although the exact cause is unknown, studies have shown that weight loss at high altitude is associated with the amount of time and severity of the altitude exposure. Upon arrival to high altitude (≥ 5000 feet), numerous physiological adaptations occur that may promote weight loss, such as increased energy expenditure and reduced appetite. The breadth of current altitude research is limited by the logistical and monetary constraints of traveling to remote locations or access to an altitude chamber. A more logistically feasible alternative is the simulation of low oxygen conditions at sea level, using a commercially available tent and generator system to reduce ambient oxygen concentrations. The current research study will evaluate changes in resting metabolic rate, appetite, and heart rate variability following overnight exposure (8 h/night) to normobaric hypoxia (NH) or normobaric normoxic (NN). In randomized order, participants will sleep one night in NH conditions (~15% oxygen; achieved with nitrogen dilution, equivalent to ~8500 feet elevation) and another night in NN (control) conditions (~20% oxygen; achieved with nitrogen dilution, equivalent to ~1000 feet elevation). In the morning, following NH or NN exposure, resting metabolic rate will be measured using indirect calorimetry, appetite using an ad libitum buffet meal protocol, and heart rate variability by electrocardiogram. It is hypothesized that exposure to overnight NH will result in increased resting metabolic rate, decreased appetite, and decreased heart rate variability.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Normobaric Hypoxia (NH) | Experimental | Device: Normobaric Hypoxia, Device: Normobaric NormoxiaOvernight exposure (8 hours) to NH conditions (~15% oxygen; achieved with nitrogen dilution, equivalent to ~8500 feet elevation) using a commercially available tent and generator system (Hypoxico, Inc., New York, NY). |
| Normobaric Normoxia (NN) | Sham comparator | Device: Normobaric Hypoxia, Device: Normobaric NormoxiaOvernight exposure (8 hours) to NN conditions (~20% oxygen; achieved with nitrogen dilution, equivalent to ~1000 feet elevation) using a commercially available tent and generator system (Hypoxico, Inc., New York, NY). |
Who may qualify
- Ages
- 20 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- Men and women aged 20 - 45 years
- Body mass index between 18.5 - 24.5 kg/m2
- Born at altitudes less than 2,100 meters (~7,000 feet)
- Currently residing in Tallahassee, Florida or the surrounding area
- Not taking any medication(s) that interfere with metabolism or oxygen delivery/transport for four weeks before and throughout the entire study (e.g., includes sedatives, sleeping aids, tranquilizers, and/or any medication that depresses ventilation, diuretics, alpha, and beta-blockers).
Key exclusion criteria (8 listed)
- Living in areas that are more than 1,200 m (~4,000 feet), or have traveled to areas that are more than 1,200 m for five days or more within the last two months
- Metabolic or cardiovascular abnormalities, gastrointestinal disorders, or any condition that interferes with metabolism or oxygen delivery/transport (e.g., kidney disease, diabetes, cardiovascular disease, etc.)
- Prior diagnosis of apnea or other sleeping disorders
- Prior diagnosis of high-altitude pulmonary edema or high-altitude cerebral edema
- Prior diagnosis of anemia or sickle cell anemia/trait
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Normobaric HypoxiaLow oxygen exposure to mimic ~8500 feet elevation. | Device | Normobaric Hypoxia (NH), Normobaric Normoxia (NN) |
| Normobaric NormoxiaNormal oxygen exposure to mimic ~1000 feet elevation (sham comparator). | Device | Normobaric Hypoxia (NH), Normobaric Normoxia (NN) |
Primary outcome
Resting metabolic rate (kcal/d) following exposure to NH or NN conditions
Time frame: 8 hours
Resting metabolic rate will be accessed using indirect calorimetry (TrueOne 2400, Parvo Medics, Salt Lake City, UT) following 8 hours of overnight exposure to NH or NN.
13 secondary outcomes
Objective appetite following exposure to NH or NN conditions
Time frame: 8 hours
Food preferences following exposure to NH or NN conditions
Time frame: 8 hours
Fasting and postprandial hunger following exposure to NH or NN conditions
Time frame: Hunger will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Fasting and postprandial satiety following exposure to NH or NN conditions
Time frame: Satiety will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Fasting and postprandial prospective food consumption following exposure to NH or NN conditions
Time frame: Prospective food consumption will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Fasting and postprandial subjective appetite following exposure to NH or NN conditions
Time frame: Subjective appetite will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Energy intake following exposure to NH or NN conditions
Time frame: 8 hours
Macronutrient intake following exposure to NH or NN conditions
Time frame: 8 hours
Heart rate variability following exposure to NH or NN conditions
Time frame: 8 hours
Prevalence of acute mountain sickness following exposure to NH or NN conditions
Time frame: 8 hours
Severity of acute mountain sickness following exposure to NH or NN conditions
Time frame: 8 hours
Continuous oxygen saturation during exposure to NH or NN
Time frame: 8 hours
Sleep quality following exposure to NH or NN conditions
Time frame: 8 hours
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Nov 2021.
- Derived from this study: PubMed 41500361Baker PA, Long AN, Dawson MA, Berryman CE. An Overnight, 8-Hour Low Oxygen Exposure Increases Energy Expenditure with No Effect on Energy Intake: A Randomized, Sham-Controlled, Crossover Study. J Nutr. 2026 Mar;156(3):101319. doi: 10.1016/j.tjnut.2025.101319. Epub 2026 Jan 5.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Claire E Berryman, Ph.D. principal investigator
Department of Nutrition, Food, and Exercise Science at Florida State University.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Normobaric Hypoxia and Normobaric Normoxia in people with Resting Metabolic Rate and Appetite, run by Florida State University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 29 Nov 2021. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Resting metabolic rate (kcal/d) following exposure to NH or NN conditions (time frame: 8 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04151927, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Nov 2021.