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Protocol Details

Energy Expenditure Responses to Different Temperatures

This study is currently recruiting participants.

Summary | Eligibility | Citations | Contacts




Sponsoring Institute

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Recruitment Detail

Type: Participants currently recruited/enrolled
Gender: Male & Female
Min Age: 18 Years
Max Age: 75 Years

Referral Letter Required


Population Exclusion(s)



Body Composition;
Healthy Volunteers;
Natural History

Recruitment Keyword(s)

Healthy Volunteer;


Normal Physiology

Investigational Drug(s)


Investigational Device(s)



Other: Room temperatures

Supporting Site

National Institute of Diabetes and Digestive and Kidney Diseases


- 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.


- 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.


- 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.


- 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.

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- 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.


- 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)

- 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.

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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. Epub 2007 May 1. Review.

Virtanen KA, Lidell ME, Orava J, Heglind M, Westergren R, Niemi T, Taittonen M, Laine J, Savisto NJ, Enerb(SqrRoot) ck S, Nuutila P. Functional brown adipose tissue in healthy adults. N Engl J Med. 2009 Apr 9;360(15):1518-25. Erratum in: N Engl J Med. 2009 Sep 10;361(11):1123.

Van 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. Erratum in: N Engl J Med. 2009 Apr 30;360(18):1917.

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Principal Investigator

Referral Contact

For more information:

Kong Y. Chen, Ph.D.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
National Institutes of Health
Building 10
Room 5-5750
10 Center Drive
Bethesda, Maryland 20892
(301) 451-1636

Margaret S. McGehee, C.R.N.P.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
NIHBC 10 - CRC BG RM 6-5740
(301) 594-6799

Office of Patient Recruitment
National Institutes of Health Clinical Center (CC)
Building 61, 10 Cloister Court
Bethesda, Maryland 20892
Toll Free: 1-800-411-1222
Local Phone: 301-451-4383
TTY: TTY Users Dial 7-1-1

Clinical Trials Number:


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