Description Module
The Description Module contains narrative descriptions of the clinical trial, including a brief summary and detailed description. These descriptions provide important information about the study's purpose, methodology, and key details in language accessible to both researchers and the general public.
Description Module path is as follows:
Study -> Protocol Section -> Description Module
Description Module
Ignite Creation Date:
2025-12-24 @ 9:09 PM
Ignite Modification Date:
2025-12-24 @ 9:09 PM
NCT ID:
NCT02939404
Brief Summary:
One reason people gain weight is eating more calories from food than what they need for energy over 24 hours. Metabolism is the amount of energy a person uses over 24 hours. Researchers want to study the relationship between changes in metabolism and how much a person eats.
Objectives:
To see how much food a person eats when the body's temperature is cooled. To study how changes in metabolism may alter the amount of food a person eats.
Eligibility:
Healthy people ages 18-55.
Design:
Participants will stay at NIH for 20 days.
During the first 4 days, participants will have:
* Medical exam
* Electrocardiogram
* Blood and urine tests. One blood test includes drinking a sugar solution.
* DXA body composition scan
* Questions about foods they like, physical activity, and personal behavior
* Exercise test on a stationary bicycle
Participants will spend 24-hour periods in a metabolic chamber. The chamber will be at normal room temperature or cooler.
Some times, participants will eat a diet that matches their daily needs (fixed or eucaloric). Other times, they can eat as much as they wish from a vending machine (ad libitum).
Participants will have blood and urine collected.
Participants will swallow an ingestible wireless sensor and wear a small data recorder device.
On the second to last day, participants will stay in the metabolic chamber but only consume water and non-caffeinated sugar-free beverages.
Participants will come back for 1-day visits at six months and one year from the first admission. They will have blood and urine tests, and a DXA scan. They will answer questions on physical activity and food habits.
Detailed Description:
More than 30% of adults are considered overweight. In general, lifestyle changes (diet and exercise) or current weight loss drugs only lead to about 5 to 10% weight loss. This may be because a person's energy expenditure, aka the number of calories the body uses, leads to hunger and may increase the amount of food a person eats. Cold exposure is known to increase metabolism but it may not lead to weight loss if appetite and the desire for food are also increased. The primary goal of this study is to evaluate whether changing energy expenditure by cool temperature exposure results in changes in food intake. This study will involve a stay on our clinical research unit where we will determine the energy requirements (at 24 degree C) of 68 healthy, adult volunteers without evidence of diabetes. Exposure to cool temperatures (19 degree C) will be used to increase the number of calories a person's body uses in a day. Participants will spend 24 hours in a room that measures energy expenditure while the temperature in the room is turned down, once with a fixed diet (eucaloric) and once with a buffet of food choices (ad libitum). After the fixed diet, volunteers will self-select how much food they wish to eat for one day from a vending machine. Volunteers will also spend one day fasting followed by a day self-selecting their food from the vending machine. Findings from this study will provide knowledge about a possible causal link between energy expenditure and eating behavior. This information may shed light on why many weight loss interventions that increase energy expenditure do not work as well as expected, and may eventually lead to new weight loss approaches and therapies.
Study:
NCT02939404
Study Brief:
Protocol Section:
NCT02939404