Room Temperature Effects on Calorie Burn in Obesity
Recruiting in Palo Alto (17 mi)
+1 other location
Age: 18+
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Academic
Recruiting
Sponsor: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Must not be taking: Antihypertensives, Metabolism-altering
Disqualifiers: Thyroid disorders, Cardiovascular disease, Diabetes, Liver disease, others
No Placebo Group
Trial Summary
What is the purpose of this trial?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.
Will I have to stop taking my current medications?
Yes, you will need to stop taking any medications, dietary supplements, or alternative therapies that are known to alter energy metabolism before participating in this trial.
What data supports the effectiveness of the treatment Room temperatures on calorie burn in obesity?
The research suggests that energy expenditure can be influenced by factors like body composition and thermogenesis (heat production in the body), which can be affected by room temperature. While not directly about room temperature, studies show that energy expenditure is higher in obese individuals due to increased fat-free mass, and thermogenesis can be stimulated by cold, hinting that room temperature might play a role in calorie burn.
12345Is it safe for humans to be exposed to different room temperatures to study calorie burn in obesity?
The research does not provide specific safety data on room temperature exposure in humans, but it discusses non-invasive methods used in animals to study energy expenditure, which suggests that similar studies in humans could be safe if conducted carefully.
46789How does room temperature affect calorie burn in obesity compared to other treatments?
This treatment is unique because it explores how room temperature can influence calorie burn in obese individuals, unlike traditional treatments that focus on diet or exercise. The study suggests that exposure to cooler temperatures may increase energy expenditure, offering a novel approach to managing obesity by potentially enhancing calorie burn without altering diet or physical activity.
210111213Eligibility Criteria
Healthy men aged 18-35 or 55-75 and healthy women aged 18-35, who are non-Hispanic whites or African Americans. Excluded are those with high blood pressure, certain BMI ranges, diabetes, abnormal kidney function, recent drug/alcohol abuse, metal implants incompatible with MRI scans, cardiovascular disease, liver disease, iron deficiency and other specific health conditions.Inclusion Criteria
Generally healthy
I am a woman aged between 18 and 35.
Self-reported non-Hispanic and non-Latino Caucasian and African-Americans
+2 more
Exclusion Criteria
Weight change >5% in the past 6 months or a trained athlete
Iron deficiency (Ferritin < 30 mcg/L males, < 15 mcg/L females)
History of illicit drug or alcohol abuse within the last 5 years; current use of drugs or alcohol
+14 more
Trial Timeline
Screening
Participants are screened for eligibility to participate in the trial
1-2 weeks
1 visit (in-person)
Inpatient Stay
Participants stay in the Metabolic Unit for up to 14 days to study energy expenditure responses to different temperatures
Up to 14 days
Daily monitoring (inpatient)
Temperature Exposure
Participants are exposed to different temperatures to measure energy expenditure, body temperature, and brown fat activity
7-13 days
Daily monitoring (inpatient)
Follow-up
Participants are monitored for any delayed effects after the inpatient stay
1-2 weeks
Participant Groups
The study is examining how the body's energy expenditure changes in response to different room temperatures ranging from about 61°F to 88°F. It aims to understand the role of brown fat in calorie burning during cold exposure by monitoring body temperature and activity levels.
5Treatment groups
Experimental Treatment
Group I: Healthy young white men with obesityExperimental Treatment1 Intervention
White men aged 18-35 years with BMI between 30.0 and 40.0 kg/m2
Group II: Healthy young lean white womenExperimental Treatment1 Intervention
White women aged 18-35 years with BMI between 18.5 and 25.0 kg/m2
Group III: Healthy young lean white menExperimental Treatment1 Intervention
White men aged 18-35 years with BMI between 18.5 and 25.0 kg/m2
Group IV: Healthy young lean black menExperimental Treatment1 Intervention
Black men aged 18-35 years with BMI between 18.5 and 25.0 kg/m2
Group V: Healthy older lean white menExperimental Treatment1 Intervention
White men aged 55-75 years with BMI between 18.5 and 25.0 kg/m2
Find a Clinic Near You
Research Locations NearbySelect from list below to view details:
National Institutes of Health Clinical CenterBethesda, MD
National Institutes of Health Clinical Center, 9000 Rockville PikeBethesda, MD
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Who Is Running the Clinical Trial?
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)Lead Sponsor
References
Thermic effect of food in lean and obese men. [2018]A systemic reappraisal of the thermic effect of food was done in lean and obese males randomly fed mixed meals containing 0, 8, 16, 24, and 32 kcal/kg fat-free mass. Densitometric analysis was used to measure body composition. Preprandial and postprandial energy expenditures were measured by indirect calorimetry. The data show that the thermic effect of food was linearly correlated with caloric intake, and that the magnitude and duration of augmented postprandial thermogenesis increased linearly with caloric consumption. Postprandial energy expenditures over resting metabolic requirements were indistinguishable when comparing lean and obese men for a given caloric intake. Individuals, however, had distinct and consistent thermic responses to progressively greater caloric challenges. These unique thermic profiles to food ingestion were also independent of leanness or obesity. We conclude that the thermic effect of food increases linearly with caloric intake, and is independent of leanness and obesity.
Energy metabolism in human obesity. [2019]Obesity results from a chronic imbalance between energy intake and expenditure. Accurate measurements of total energy expenditure of lean and obese individuals with a respiration chamber have clearly shown that obese individuals expand more energy than lean sedentary subjects. Studies on the body composition of obese individuals reveal that not only the fat mass is enlarged, but the fat-free mass is also increased as compared with that of lean subjects. Since basal metabolic rate is proportional to the fat-free mass, obese subjects have a greater basal metabolic rate than lean controls. The energy cost of weight bearing activities such as walking and standing is related to body weight, and is therefore increased in obese individuals. The thermogenic response to food ingestion, the diet-induced thermogenesis, has been found to be reduced in some groups of obese people, but not in all obese individuals. The thermic effect of glucose or to meal ingestion is blunted in obese subjects with insulin resistance. Any alteration in thermogenic responses to a caloric excess can be important to store or to oxidize part of the excessive energy intake. After weight reduction in obese subjects due to a hypocaloric diet, the total 24-hour energy expenditure decreases by 20 to 25 kcal/day for each kilogram of weight loss. Failure to adapt the every day energy intake accordingly will result in body weight gain and relapse of obesity.
Hand-held indirect calorimeter offers advantages compared with prediction equations, in a group of overweight women, to determine resting energy expenditures and estimated total energy expenditures during research screening. [2009]To compare standardized prediction equations to a hand-held indirect calorimeter in estimating resting energy and total energy requirements in overweight women.
Diet-induced thermogenesis: fake friend or foe? [2019]Diet-induced thermogenesis (DIT) is energy dissipated as heat after a meal, contributing 5-15% to total daily energy expenditure (EE). There has been a long interest in the intriguing possibility that a defect in DIT predisposes to obesity. However, the evidence is conflicting; DIT is usually quantified by indirect calorimetry, which does not measure heat. Using gas exchange, indirect calorimetry measures total post-prandial EE, which comprises heat energy produced from brown adipose tissue (BAT) and energy required for processing and storing nutrients. We questioned whether DIT is reliably quantified by indirect calorimetry by employing infrared thermography to independently assess thermogenesis. Thermogenic activity of BAT was stimulated by cold and by a meal that induced a parallel increase in energy production. These stimulatory effects on BAT thermogenesis were inhibited by glucocorticoids. However, glucocorticoids enhanced postprandial EE in the face of reduced BAT thermogenesis and stimulated lipid synthesis. The increase in EE correlated significantly with the increase in lipogenesis. As energy cannot be destroyed (first law of thermodynamics), the energy that would have been dissipated as heat after a meal is channeled into storage. Post-prandial EE is the sum of heat energy that is lost (true DIT) and chemical energy that is stored. Indirect calorimetry does not reliably quantify DIT. When estimated by indirect calorimetry, assumed DIT can be a friend or foe of energy balance. That gas exchange-derived DIT reflects solely energy dissipation as heat is a false assumption likely to explain the conflicting results on the role of DIT in obesity.
Reliability of the measurement of postprandial thermogenesis in men of three levels of body fatness. [2019]To determine the reliability of the measurement of postprandial thermogenesis by indirect calorimetry and to clarify further the relationship of obesity to thermogenesis in men, the thermic effect of a 720-kcal, mixed liquid meal was compared in 13 lean men (mean +/- SEM, 11.2% +/- 1.4% body fat), 10 average men (22.4% +/- 1.6% body fat), and 12 obese men (33.4% +/- 1.6% body fat) on two occasions. Resting metabolic rate (RMR) was measured for 3 hours: (1) in the fasted state, and (2) after a 720-kcal mixed liquid meal, on two occasions. The thermic effect of the meal, calculated as the postprandial energy expenditure minus the fasting RMR (kcal/3h), was greater for the lean and average men than for the obese men during both trials (P less than .001), but was only marginally different between the lean and average groups (P = .16). The mean values for the two trials were similar and the measurement of thermogenesis was highly reproducible with a reliability coefficient of r = .932 (P less than .001). Across all groups, thermogenesis correlated strongly with percent body fat (r = -.64, P less than .01), but within the average men, thermogenesis was uncorrelated with percent body fat (r = .09) but highly correlated with the glucose response to the meal (r = -.75, P less than .05). Thus, factors other than body fatness, such as insulin sensitivity, may determine thermogenesis within this heterogeneous middle group.(ABSTRACT TRUNCATED AT 250 WORDS)
Measurement and characterization of energy expenditure as a tool in the development of drugs for metabolic diseases, such as obesity and diabetes. [2016]The need for treatment of obesity and obesity-related diseases, such as type 2 diabetes, has been intensified by the epidemic rise of obesity. Recent advances make possible continuous monitoring of metabolically relevant functions in animals to identify novel thermogenic and anorectic compounds. This unit describes non-invasive in vivo calorimetric assessment of energy expenditure using measurements of oxygen consumption and carbon dioxide production, complemented by telemetric monitoring of body core temperature and locomotor activity in mice and rats. Reference compounds are used to illustrate the determination of substance-specific parameters, such as the dose that produces the half-maximal effect (ED(50)), the maximal effect, as well as the time of onset and duration of compound action. Indirect calorimetry performed at different temperatures provides information on several other well-defined parameters, including resting metabolic rate, basal metabolic rate, lower critical temperature, temperature sensitivity, defended body temperature, and respiratory quotient.
Characterization of energy expenditure in rodents by indirect calorimetry. [2016]The need for treatment of obesity and obesity-related diseases, such as type 2 diabetes, has been intensified by the epidemic rise of obesity. Recent advances make possible continuous monitoring of metabolically relevant functions in animals to identify novel thermogenic and anorectic compounds. This unit describes non-invasive in vivo calorimetric assessment of energy expenditure using measurements of oxygen consumption and carbon dioxide production, complemented by telemetric monitoring of body core temperature and locomotor activity in mice and rats. Reference compounds are used to illustrate the determination of substance-specific parameters, such as the dose that produces the half-maximal effect (ED(50)), the maximal effect, as well as the time of onset and duration of compound action. Indirect calorimetry performed at different temperatures provides information on several other well-defined parameters, including resting metabolic rate, basal metabolic rate, lower critical temperature, temperature sensitivity, defended body temperature, and respiratory quotient.
The thermic effect of food is reduced in older adults. [2021]The thermic effect of food accounts for ~10% of daily energy expenditure. A reduction in the thermic effect of food, which has been variably observed in the older adults, could predispose to fat gain. We tested whether the thermic effect of food is reduced in older adults compared with young adults by analyzing our database of standardized studies conducted at the Mayo Clinic between 1999 and 2009. Data were available from 136 older adult volunteers aged 60-88 (56 females) and 141 young adults aged 18-35 years (67 females). Basal energy expenditure was measured by indirect calorimetry to assess basal metabolic rate. Body fat, fat free mass, and visceral fat were measured using a combination of dual energy X-ray absorptiometry and an abdominal CT scan. The thermic effect of food and postprandial insulinemia were measured in 123 older adults (52 females) and 86 young adults (38 females) of these volunteers. Basal metabolic rate adjusted for fat-free mass was less in older adults (p=0.01) and the thermic effect of food was ~1% (p=0.02) less in the older adults. After controlling for meal size and fat-free mass, body fat and fat distribution did not predict the thermic effect of food. Both basal metabolic rate and the thermic effect of food are less in older adults than young adults, even when they have similar amounts of lean tissue and consume a similar size meal. These factors contribute to lower daily energy expenditure in the older adults.
Quantification of the Capacity for Cold-Induced Thermogenesis in Young Men With and Without Obesity. [2020]Cold exposure increases energy expenditure (EE) and could have a role in combating obesity. To understand this potential, we determined the capacity for cold-induced thermogenesis (CIT), the EE increase above the basal metabolic rate at the individualized coldest tolerable temperature before overt shivering.
Effect of moderate cold exposure on 24-h energy expenditure: similar response in postobese and nonobese women. [2019]Twenty-four-hour energy expenditure (EE) and substrate oxidation rates were measured two times in eight postobese women and eight matched controls. On one occasion the subjects were exposed to a room temperature of 16 degrees C, on the other to 24 degrees C. Cold exposure elicited a 2% increment in 24-h EE (P
Energy metabolism in women during short exposure to the thermoneutral zone. [2022]Ambient temperature has been shown to affect energy metabolism in field situations. Therefore, we assessed the effect of a short exposure to the thermoneutral zone, i.e., 27 degrees C (81 degrees F), in comparison to the usual ambient temperature of 22 degrees C (72 degrees F), on energy expenditure (EE), substrate oxidation, and energy intake (EI) in a controlled situation. Subjects, i.e., women (ages 22+/-2 years, BMI 22+/-3, 28+/-4% body fat), stayed in a respiration chamber three times for 48 h each: once at 22 degrees C, and twice at 27 degrees C in random order, wearing standardized clothing, executing a standardized daily-activities protocol, and being fed in energy balance (EB). During the last 24 h at 22 degrees C, and once during the last 24 h at 27 degrees C, they were fed ad libitum. At 27 degrees C, compared to at 22 degrees C, EE was 8.9+/-1.3 MJ/day vs. 9.9+/-1.5 MJ/day (P
Postprandial resting metabolic rate and body composition in the moderately obese and normal-weight adult subjects at sitting posture. [2019]A reduced metabolic rate in the etiology of obesity has been a subject of controversy. The prediction of the energy requirements for the obese using reference values may therefore be distorted. In order to examine this possibility, resting metabolic rate (RMR) while the subject was sitting comfortably in a chair was measured in a total of 134 moderately obese and normal-weight subjects (68 women aged 20 to 71 with a mean of 53.1 and 66 men aged 20 to 63 with a mean of 36.5). RMR per kg of body weight was significantly lower in the female obese subjects, but not in the male obese subjects. There was no evidence of difference in RMR between obese and normal-weight subjects in either sex when RMR was indexed with fat-free mass (FFM), indicating no substantial decrease in the metabolism due to obesity. Multiple regression analyses indicate that standardization of RMR by FFM eliminates the apparent difference in RMR between the sexes, and the diminution of RMR with age was not observed. While the best and logical prediction of RMR is to use FFM, regression analyses suggest an alternative way of predicting RMR by an incorporation of subscapular skinfold thickness to adjust the different body composition in lean and obese subjects. Prediction equations of postprandial RMR (kcal/24-h) while sitting are RMR = 24.5 x FFM(kg) + 303.7, and RMR = 22.7 x weight(kg) - 13.6 x SSF (subscapular skinfold: mm) + 350.6. Problems in predicting RMR are discussed.
Obesity, diet and body temperature. [2018]Studies conducted thus far on the pathogenesis of obesity have not clearly determined the role of body temperature in the energy balance. In an attempt to explore this relationship further, research has been undertaken, a part of which is represented by the present investigation carried out on 22 adult males: 11 having a BMI less than or equal to 25 (group A) and 11 with BMI greater than 25 (group B). Body temperature was measured by mouth and on the skin surface (in 4 points according to Ramanathan) on 2 consecutive days (every 30 min from noon to 6:30 p.m.), the 1st day with the participants fasting and the 2nd day after consumption of a meal whose energy content represented a part (45%) of the 24-hour energy intake of the subjects, as previously ascertained by a survey of their food consumption. The study was carried out under frequently checked microclimatic conditions. During the week prior to the measurements, the alimentary consumption of the subjects was monitored by direct weighing for 5 consecutive days. A significant rise in body temperature, probably due to dietary thermogenesis, was observed in group A (internal temperature: F = 13.05; skin temperature: F = 6.48) as well as in group B (internal temperature: F = 24.88; skin temperature: F = 5.35) after the meal. However in group B the skin temperature showed a smaller increase than in group A (delta t degree 0.31 vs. 0.49) and an earlier trend towards the basal values (nearly 5 vs. 6 h after the meal). In both groups a decrease in the skin delta t degrees is evident at 3 and 3.5 h, respectively, after the meal, followed by a more remarkable increase in this difference between the 4th and the 5th hour. The meaning of this decrease as well as the difference in body temperature versus caloric intake is discussed. Normal weight individuals demonstrated a positive correlation (r = 0.83) between usual caloric intake per square meter of body surface and fasting internal body temperature. This correlation was not observed in subjects with BMI greater than 25.