ObesityNCT01568671
Energy Expenditure Responses to Different Temperatures
A study testing Room temperatures in people with Obesity and Normal Physiology, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at 1 site in United States.
Trial summary
Background: The way that the body burns calories is known as energy expenditure. Some studies show that when we are cold, we burn more calories to keep our bodies warm. Brown fat is a special kind of fat that can use energy to keep the body warm. Read more about this study
- Who is it for?
- Ages 18 to 75 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity, Normal Physiology
- What is being tested?
- Room temperatures
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 104 participants
- Where
- 1 siteUnited States
- Study dates
- 24 Apr 2012to 14 Nov 2019
- 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 18 to 75 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Generally healthy.
- Males between the age greater than or equal to 18 -35 years or between 55-75 years, male orand females between the age 18-35 years.
- Self-reported non-Hispanic and non-Latino Caucasian and African-Americans
- Written informed consent.
Who cannot join
- Hypo- or hyper-thyroid (history or TSH >5.0<0.4 miU/L)
- Psychological conditions,such as (but not limited to) claustrophobia, clinical depression, bipolar disorders, that would be incompatible with safe and successful participation in this study
- Weight change >5% in the past 6 months or a trained athlete
- Blood pressure greater than 140/90 mmHg or current antihypertensive therapy
- History of cardiovascular disease
- BMI <18.5, between 25.1-29.9, and >40 Kg/m(2)
Show all 18Show fewer
- Diabetes mellitus (fasting serum glucose > 126 mg/dL)
- Liver disease or ALT serum level greater than two times the laboratory upper limit of normal
- Iron deficiency (Ferritin < 30 mcg/L males, < 15 mcg/L females)
- Abnormal kidney function (eGFR<60 ml/min/1.73m(2))
- History of illicit drug or alcohol abuse within the last 5 years; current use of drugs (by history) or alcohol (CAGE greater than or equal to 2)
- Current use of medications/dietary supplements/alternative therapies known to alter energy metabolism
- Pregnancy/breastfeeding/hormonal contraception or childbirth within the last year
- Perimenopausal (as self-described within two years from onset of amenorrhea or current complaints of hot flashes)
- For pre-menopausal women, irregular periods or polycystic ovarian disease
- Current smoker or user of tobacco products
- Metal implant that prevents subject from being in a MRI scanner.
- All subjects will be fully informed of the aims, nature, and risks of the study prior to giving written informed consent.
Trial locations and contacts
1 site in 1 country.
United States1 site
National Institutes of Health Clinical Center
Bethesda, Maryland, 20892
About this study
Background:
- The way that the body burns calories is known as energy expenditure. Some studies show that when we are cold, we burn more calories to keep our bodies warm. Brown fat is a special kind of fat that can use energy to keep the body warm. Small animals and infants have been known to have brown fat for many years. Recently, it has been suggested that adult humans also have brown fat. If brown fat becomes active (burns calories) in adult humans when exposed to cold, then these people would tend to burn off more calories and might not gain weight easily. Learning more about the relationship between energy expenditure, brown fat, environmental temperature, and body temperature may help explain why some people become obese and other people do not.
Read more
Objectives:
- To better understand how the body burns calories when exposed to different temperatures.
- To study brown fat and how it burns calories in cold temperatures.
Eligibility:
- Healthy men between 18 and 35 or 55 and 75 years of age.
- Healthy women between 18 and 35 years of age.
- To control for ethnicity, participants must be non-Hispanic whites or African Americans.
Design:
- Participants will be screened with a physical exam and medical history. Blood and urine samples will be collected.
- Participants will stay in the Metabolic Unit of the National Institutes of Health Clinical Center as inpatients for no more than 14 days. The length of the hospital stay will depend on how participants respond to the different study temperatures.
- Every afternoon, participants will walk for 30 minutes on a treadmill. All meals will be provided.
- Participants will stay up to 5 hours per day in a specialized room with different temperature settings. Temperatures will range from about 61 degrees to 88 degrees Fahrenheit. Body temperature, activity, calorie burning, and cold/hot sensations will be monitored. On the study day of the coldest temperature, participants will have an imaging study to look for brown fat activity.
- Participants will be compensated for their time and participation at the end of the study.
Read the detailed description
Surprisingly little is understood about how the body regulates heat production (energy expenditure, EE) in response to subtle changes in environmental temperature. For example, only recently has it been realized that brown adipose tissue is functional in adult humans. It is plausible that the mechanisms governing heat production contribute to regulation of body weight and thus may be contributing to the current obesity epidemic: even small changes in EE, if not compensated by changes in food intake, can have long-term effects on body weight.
The thermoneutral zone (TNZ) is the environmental temperature range over which EE is at a minimum and does not change with environmental temperature. The lower and upper critical temperatures define the temperature limits of the TNZ. At environmental temperatures below the lower critical temperature, the EE vs. environmental temperature graph is reported to be a straight line with the extrapolated X-axis intercept being the defended body temperature. Some of these parameters are predicted to be different for obese as compared to lean individuals. With the global obesity epidemic coinciding with improved indoor temperature control, a better understanding of the relationship between EE and thermoregulation is desirable.
This protocol has three phases. The first is a pilot in lean males to optimize procedures and establish the feasibility, sensitivity, and behavior of the assays. Second, lean and obese male cohorts will be compared to ensure that the expected differences can be observed. Third, additional variables will be examined, such as age, race, sex, and menstrual phase in women.
Specifically, we will map the resting EE response to environmental temperatures from 16-31 degrees Celsius during inpatient stays in the NIH Metabolic Clinical Research Unit. Each day resting EE will be measured in a room respiration calorimeter with a different environmental temperature (subjects will be blinded as to room temperature). The remainder of each study day will be spent at 23-25 degrees Celsius in the individual patient room.
Standard diet and physical activity will be maintained and body weight will be held stable. Additionally core body and skin temperatures, heart rate and variability, muscle activity by surface electromyography, and thermal comfort and hunger using visual analog scales will be measured.
This study will establish techniques and provide baseline normative data, allowing insight into the mechanisms regulating the EE in humans and how these are affected by obesity. It is envisioned that this study will provide the basis for investigation of the effects of acute and chronic weight change and the effects of drug therapy.
- Conditions
- Obesity, Normal Physiology
- Being tested
- Room temperatures
- Keywords
- Adult, Body Composition, Accelerometry, Healthy Volunteers, Thermoregulation, Natural History, Healthy Volunteer, HV
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Room temperaturesOther
Room temperature of metabolic chamber set between 16C and 31C
| Study group | Role | What they receive |
|---|---|---|
| Healthy older lean white men | Experimental | White men aged 55-75 years with BMI between 18.5 and 25.0 kg/m2 Receives: Other: Room temperatures |
| Healthy young lean black men | Experimental | Black men aged 18-35 years with BMI between 18.5 and 25.0 kg/m2 Receives: Other: Room temperatures |
| Healthy young lean white men | Experimental | White men aged 18-35 years with BMI between 18.5 and 25.0 kg/m2 Receives: Other: Room temperatures |
| Healthy young lean white women | Experimental | White women aged 18-35 years with BMI between 18.5 and 25.0 kg/m2 Receives: Other: Room temperatures |
| Healthy young white men with obesity | Experimental | White men aged 18-35 years with BMI between 30.0 and 40.0 kg/m2 Receives: Other: Room temperatures |
What is being measured
The primary outcome is the main question the study is designed to answer.
Resting energy expenditure
Resting energy expenditure at the lowest tolerable temperature above basal metabolic rate (%), measured by metabolic chamber
Measured: Days 7-13 of inpatient stay
Secondary outcomes (1)
Mean skin temperature
Weighted average of skin temperatures measured by iBottons at the chest, upper arm, upper leg, and lower leg
Measured: Days 1-14
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Apr 2012 (estimated)
- Study start24 Apr 2012
- Primary completion14 Nov 2019
- Study completion14 Nov 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for ObesityStudies of the same condition, open and under way.
- More trials run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)The 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
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 104 participants (actual)
Sponsor and investigators
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
- Investigators
- Kong Y Chen, Ph.D., Principal investigator, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01568671
- Sponsor's protocol ID
- 120097
- Other IDs
- 12-DK-0097
- Status last verified
- 10 Jul 2026
- First submitted
- 30 Mar 2012
- Last updated
- 27 Aug 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified IPD underlying the primary results
Publications
Nedergaard J, Bengtsson T, Cannon B. Unexpected evidence for active brown adipose tissue in adult humans. Am J Physiol Endocrinol Metab. 2007 Aug;293(2):E444-52. doi: 10.1152/ajpendo.00691.2006. Epub 2007 May 1.
PubMed 17473055Virtanen KA, Lidell ME, Orava J, Heglind M, Westergren R, Niemi T, Taittonen M, Laine J, Savisto NJ, Enerback S, Nuutila P. Functional brown adipose tissue in healthy adults. N Engl J Med. 2009 Apr 9;360(15):1518-25. doi: 10.1056/NEJMoa0808949.
PubMed 19357407van Marken Lichtenbelt WD, Vanhommerig JW, Smulders NM, Drossaerts JM, Kemerink GJ, Bouvy ND, Schrauwen P, Teule GJ. Cold-activated brown adipose tissue in healthy men. N Engl J Med. 2009 Apr 9;360(15):1500-8. doi: 10.1056/NEJMoa0808718.
PubMed 19357405Ouwerkerk R, Hamimi A, Matta J, Abd-Elmoniem KZ, Eary JF, Abdul Sater Z, Chen KY, Cypess AM, Gharib AM. Proton MR Spectroscopy Measurements of White and Brown Adipose Tissue in Healthy Humans: Relaxation Parameters and Unsaturated Fatty Acids. Radiology. 2021 May;299(2):396-406. doi: 10.1148/radiol.2021202676. Epub 2021 Mar 16.
PubMed 33724063Brychta RJ, Huang S, Wang J, Leitner BP, Hattenbach JD, Bell SL, Fletcher LA, Perron Wood R, Idelson CR, Duckworth CJ, McGehee S, Courville AB, Bernstein SB, Reitman ML, Cypess AM, Chen KY. Quantification of the Capacity for Cold-Induced Thermogenesis in Young Men With and Without Obesity. J Clin Endocrinol Metab. 2019 Oct 1;104(10):4865-4878. doi: 10.1210/jc.2019-00728.
PubMed 31150063
Study at a glance
From the registry record, last updated by the sponsor on 27 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Energy Expenditure Responses to Different Temperatures
- ClinicalTrials.gov ID
- NCT01568671
- Acronym / sponsor ID
- 120097
- Conditions
- Obesity, Normal Physiology
- Keywords
- Adult, Body Composition, Accelerometry, Healthy Volunteers, Thermoregulation, Natural History, Healthy Volunteer, HV
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 104 participants (actual)
- Lead sponsor
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)US National Institutes of Health
- Study start
- 24 Apr 2012 (actual)
- Primary completion
- 14 Nov 2019 (actual)
- Study completion
- 14 Nov 2019 (actual)
- First posted
- 2 Apr 2012 (estimated)
- 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.
Background:
- The way that the body burns calories is known as energy expenditure. Some studies show that when we are cold, we burn more calories to keep our bodies warm. Brown fat is a special kind of fat that can use energy to keep the body warm. Small animals and infants have been known to have brown fat for many years. Recently, it has been suggested that adult humans also have brown fat. If brown fat becomes active (burns calories) in adult humans when exposed to cold, then these people would tend to burn off more calories and might not gain weight easily. Learning more about the relationship between energy expenditure, brown fat, environmental temperature, and body temperature may help explain why some people become obese and other people do not.
Objectives:
- To better understand how the body burns calories when exposed to different temperatures.
- To study brown fat and how it burns calories in cold temperatures.
Eligibility:
- Healthy men between 18 and 35 or 55 and 75 years of age.
- Healthy women between 18 and 35 years of age.
- To control for ethnicity, participants must be non-Hispanic whites or African Americans.
Design:
- Participants will be screened with a physical exam and medical history. Blood and urine samples will be collected.
- Participants will stay in the Metabolic Unit of the National Institutes of Health Clinical Center as inpatients for no more than 14 days. The length of the hospital stay will depend on how participants respond to the different study temperatures.
- Every afternoon, participants will walk for 30 minutes on a treadmill. All meals will be provided.
- Participants will stay up to 5 hours per day in a specialized room with different temperature settings. Temperatures will range from about 61 degrees to 88 degrees Fahrenheit. Body temperature, activity, calorie burning, and cold/hot sensations will be monitored. On the study day of the coldest temperature, participants will have an imaging study to look for brown fat activity.
- Participants will be compensated for their time and participation at the end of the study.
Detailed description
Surprisingly little is understood about how the body regulates heat production (energy expenditure, EE) in response to subtle changes in environmental temperature. For example, only recently has it been realized that brown adipose tissue is functional in adult humans. It is plausible that the mechanisms governing heat production contribute to regulation of body weight and thus may be contributing to the current obesity epidemic: even small changes in EE, if not compensated by changes in food intake, can have long-term effects on body weight.
The thermoneutral zone (TNZ) is the environmental temperature range over which EE is at a minimum and does not change with environmental temperature. The lower and upper critical temperatures define the temperature limits of the TNZ. At environmental temperatures below the lower critical temperature, the EE vs. environmental temperature graph is reported to be a straight line with the extrapolated X-axis intercept being the defended body temperature. Some of these parameters are predicted to be different for obese as compared to lean individuals. With the global obesity epidemic coinciding with improved indoor temperature control, a better understanding of the relationship between EE and thermoregulation is desirable.
This protocol has three phases. The first is a pilot in lean males to optimize procedures and establish the feasibility, sensitivity, and behavior of the assays. Second, lean and obese male cohorts will be compared to ensure that the expected differences can be observed. Third, additional variables will be examined, such as age, race, sex, and menstrual phase in women.
Specifically, we will map the resting EE response to environmental temperatures from 16-31 degrees Celsius during inpatient stays in the NIH Metabolic Clinical Research Unit. Each day resting EE will be measured in a room respiration calorimeter with a different environmental temperature (subjects will be blinded as to room temperature). The remainder of each study day will be spent at 23-25 degrees Celsius in the individual patient room.
Standard diet and physical activity will be maintained and body weight will be held stable. Additionally core body and skin temperatures, heart rate and variability, muscle activity by surface electromyography, and thermal comfort and hunger using visual analog scales will be measured.
This study will establish techniques and provide baseline normative data, allowing insight into the mechanisms regulating the EE in humans and how these are affected by obesity. It is envisioned that this study will provide the basis for investigation of the effects of acute and chronic weight change and the effects of drug therapy.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| Healthy older lean white men | Experimental | Other: Room temperaturesWhite men aged 55-75 years with BMI between 18.5 and 25.0 kg/m2 |
| Healthy young lean black men | Experimental | Other: Room temperaturesBlack men aged 18-35 years with BMI between 18.5 and 25.0 kg/m2 |
| Healthy young lean white men | Experimental | Other: Room temperaturesWhite men aged 18-35 years with BMI between 18.5 and 25.0 kg/m2 |
| Healthy young lean white women | Experimental | Other: Room temperaturesWhite women aged 18-35 years with BMI between 18.5 and 25.0 kg/m2 |
| Healthy young white men with obesity | Experimental | Other: Room temperaturesWhite men aged 18-35 years with BMI between 30.0 and 40.0 kg/m2 |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Generally healthy.
- Males between the age greater than or equal to 18 -35 years or between 55-75 years, male orand females between the age 18-35 years.
- Self-reported non-Hispanic and non-Latino Caucasian and African-Americans
- Written informed consent.
Key exclusion criteria (18 listed)
- Hypo- or hyper-thyroid (history or TSH >5.0<0.4 miU/L)
- Psychological conditions,such as (but not limited to) claustrophobia, clinical depression, bipolar disorders, that would be incompatible with safe and successful participation in this study
- Weight change >5% in the past 6 months or a trained athlete
- Blood pressure greater than 140/90 mmHg or current antihypertensive therapy
- History of cardiovascular disease
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 |
|---|---|---|
| Room temperaturesRoom temperature of metabolic chamber set between 16C and 31C | Other | Healthy older lean white men, Healthy young lean black men, Healthy young lean white men, Healthy young lean white women, Healthy young white men with obesity |
Primary outcome
Resting energy expenditure
Time frame: Days 7-13 of inpatient stay
Resting energy expenditure at the lowest tolerable temperature above basal metabolic rate (%), measured by metabolic chamber
1 secondary outcome
Mean skin temperature
Time frame: Days 1-14
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 27 Aug 2026.
- Background: PubMed 17473055Nedergaard J, Bengtsson T, Cannon B. Unexpected evidence for active brown adipose tissue in adult humans. Am J Physiol Endocrinol Metab. 2007 Aug;293(2):E444-52. doi: 10.1152/ajpendo.00691.2006. Epub 2007 May 1.
- Background: PubMed 19357407Virtanen KA, Lidell ME, Orava J, Heglind M, Westergren R, Niemi T, Taittonen M, Laine J, Savisto NJ, Enerback S, Nuutila P. Functional brown adipose tissue in healthy adults. N Engl J Med. 2009 Apr 9;360(15):1518-25. doi: 10.1056/NEJMoa0808949.
- Background: PubMed 19357405van Marken Lichtenbelt WD, Vanhommerig JW, Smulders NM, Drossaerts JM, Kemerink GJ, Bouvy ND, Schrauwen P, Teule GJ. Cold-activated brown adipose tissue in healthy men. N Engl J Med. 2009 Apr 9;360(15):1500-8. doi: 10.1056/NEJMoa0808718.
- Derived from this study: PubMed 33724063Ouwerkerk R, Hamimi A, Matta J, Abd-Elmoniem KZ, Eary JF, Abdul Sater Z, Chen KY, Cypess AM, Gharib AM. Proton MR Spectroscopy Measurements of White and Brown Adipose Tissue in Healthy Humans: Relaxation Parameters and Unsaturated Fatty Acids. Radiology. 2021 May;299(2):396-406. doi: 10.1148/radiol.2021202676. Epub 2021 Mar 16.
- Derived from this study: PubMed 31150063Brychta RJ, Huang S, Wang J, Leitner BP, Hattenbach JD, Bell SL, Fletcher LA, Perron Wood R, Idelson CR, Duckworth CJ, McGehee S, Courville AB, Bernstein SB, Reitman ML, Cypess AM, Chen KY. Quantification of the Capacity for Cold-Induced Thermogenesis in Young Men With and Without Obesity. J Clin Endocrinol Metab. 2019 Oct 1;104(10):4865-4878. doi: 10.1210/jc.2019-00728.
- NIH Clinical Center Detailed Web PageLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. De-identified IPD underlying the primary results
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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.
Kong Y Chen, Ph.D. principal investigator
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Room temperatures in people with Obesity and Normal Physiology, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) 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 4 inclusion and 18 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 27 Aug 2026. 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. 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 energy expenditure (time frame: Days 7-13 of inpatient stay). 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 NCT01568671, which also lists 5 linked publications.
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 27 Aug 2026.