Energy Expenditure and Substrate Oxidation in a Whole Room Calorimeter

Study Overview
=================
Brief Summary
-----------------
The investigators aim to establish a protocol for metabolic rate measurements obtained using continuous monitoring of oxygen consumption and carbon dioxide production in a whole room calorimeter setting.

Detailed Description
-----------------
The purpose of this study is to determine the duration and time course of the thermic effect of single meals consumed by subjects who have been previously fasting for 12 hours overnight. Capturing the full thermic effect of a meal may take up to 8 hours, depending on the calorie load, nutrient composition of the meal, and rate of digestion. The investigators will test meals consisting of conventional foods that are low (20% of energy), moderate (40% of energy) or high (60% of energy) in fat calories, as fat is thought to slow the digestive process. The investigators will test a liquid meal, that is high (60% of energy) in fat calories, as liquid foods are thought to move more quickly through the digestive process. Another purpose of this study is to determine the test-retest reproducibility for the meals described above. To accomplish reproducibility, a volunteer will be permitted to repeat a test day two times using the same test meal.

Official Title
-----------------
Establishing Short-term Protocols for Measuring Resting and Postprandial Energy Expenditure and Substrate Oxidation in a Whole Room Calorimeter

Conditions
-----------------
Overweight, Obesity, Body Weight

Intervention / Treatment
-----------------
* Other: Low fat meal
* Other: Moderate fat meal
* Other: High fat meal
* Other: High fat liquid meal


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Body Mass Index 18.5 - 39.9 kg/m2 Exclusion Criteria: BMI < 18.5 or > 40 kg/m2 Presence of untreated or uncontrolled metabolic diseases Presence of gastrointestinal distress or disorders that prevent consumption of a study meal (in particular, the high fat meals) Presence of Crohn's disease, irritable bowel syndrome, or colitis Previous gallbladder removal Presence of cancer or other serious chronic disease Implanted medical device that is battery operated, such as a pacemaker, defibrillator, electrocardiograph, or nerve simulator Presence of a large amount of metal in the body such as a hip implant Current use of tobacco in any form Claustrophobia Dietary restrictions that would interfere with consuming study meals Pregnant or nursing within the last 6 months, or plan to become pregnant

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: The study will be a randomized design that includes a volunteer receiving one of four test meals.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Meal 1<br>Meal consisting of conventional foods that is low (20% of energy) in fat calories. | Other: Low fat meal<br>* Meal consisting of conventional foods that is low (20% of energy) in fat calories.<br>|
| Experimental: Meal 2<br>Meal consisting of conventional foods that is moderate (40% of energy) in fat calories. | Other: Moderate fat meal<br>* Meal consisting of conventional foods that is moderate (40% of energy) in fat calories.<br>|
| Experimental: Meal 3<br>Meal consisting of conventional foods that is high (60% of energy) in fat calories. | Other: High fat meal<br>* Meal consisting of conventional foods that is high (60% of energy) in fat calories.<br>|
| Experimental: Meal 4<br>A liquid meal, similar to a smoothie, that is high (60% of energy) in fat calories. | Other: High fat liquid meal<br>* Liquid meal that is high (60% of energy) in fat calories.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Baseline level and change in rate of oxygen consumption | Oxygen consumption rate (VO2/min) measured by gas analyzer while inside whole room calorimeter | Measured continuously from baseline up to 600 minutes post-meal | 
| Baseline level and change in rate of carbon dioxide production | Carbon dioxide production rate (VCO2/min) measured by gas analyzer while inside whole room calorimeter | Measured continuously from baseline up to 600 minutes post-meal | 
| Baseline level and change in respiratory exchange ratio (RER) | RER is expressed as the ratio of VCO2 to VO2 | Measured continuously from baseline up to 600 minutes post-meal | 
| Baseline level and change in urinary nitrogen excretion | Urinary nitrogen measured via combustion and gas analysis in mg | Measured from discrete specimens and a pooled urine sample collected up to 600 minutes post-meal while in the room calorimeter | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Body weight | measured in kg | Baseline | 
| Body fat | Measured in kg using multi frequency bioimpedance | Baseline | 
| Lean body mass | Measured in kg using multi frequency bioimpedance | Baseline | 
| Total body water | Measured in kg using multi frequency bioimpedance | Baseline | 
| Waist circumference | measured in cm | Baseline | 
| Hip circumference | measured in cm | Baseline | 
| Blood pressure | Both systolic and diastolic pressure measured in mmHg using automated instrument | Baseline | 
| Heart rate | measured in beats per minute using automated instrument | Baseline | 
| Body temperature | measured in centigrade | Baseline | 
| General health and well-being | The SF-36 Short form general health and well-being questionnaire measured once. The survey has eight scales; physical functioning, role limitations due to physical health, role limitations due to emotional problems, energy/fatigue, emotional well-being, social functioning, pain, general health. All 36 items are scored so that a high score defines a more favorable health state. Each item is scored on a 0 to 100 range so that the lowest and highest possible scores are 0 and 100, respectively. Items in the same scale are averaged together to create the 8 scale scores. | Baseline | 
| Usual physical activity | Physical activity estimated from the Stanford Brief Physical Activity questionnaire. Scale is categorical for two subscales: work physical activity and leisure time activity. | Baseline | 
| Baseline level and change in satiety | Self-reported feelings of fullness measured on a visual analog scale. Responses will be a marked on an unsegmented line from 0 or not at all to 100 or extremely. | Baseline, and 5, 10, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, 360, 390, 420, 450, and 480 minutes after meal | 
| Baseline level and change in hunger | Self-reported feelings of hunger measured on a visual analog scale. Responses will be a marked on an unsegmented line from 0 or not at all to 100 or extremely. | Baseline, and 5, 10, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, 360, 390, 420, 450, and 480 minutes after meal | 
| Baseline level and change in desire to eat | Self-reported feelings of the desire to eat measured on a visual analog scale. Responses will be a marked on an unsegmented line from 0 or not at all to 100 or extremely. | Baseline, and 5, 10, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, 360, 390, 420, 450, and 480 minutes after meal | 
| Baseline level and change in prospective consumption | Self-reported feelings of prospective consumption measured on a visual analog scale. Responses will be a marked on an unsegmented line from 0 or not at all to 100 or extremely. | Baseline, and 5, 10, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, 360, 390, 420, 450, and 480 minutes after meal | 
| Baseline level and change in energy expenditure | Calculated as kcal/min from oxygen consumption and carbon dioxide production (L/min) and urinary nitrogen excretion (g/min) | Expressed from baseline up to 600 minutes post-meal | 
| Baseline level and change in carbohydrate combustion | Calculated as g/min from oxygen consumption and carbon dioxide production (L/min) and urinary nitrogen excretion (g/min) | Expressed from baseline up to 600 minutes post-meal | 
| Baseline level and change in fat combustion | Calculated as g/min from oxygen consumption and carbon dioxide production (L/min) and urinary nitrogen excretion (g/min) | Expressed from baseline up to 600 minutes post-meal | 
| Baseline level and change in thermic effect of food (TEF) | Calculated as the increase in post-meal energy expenditure above baseline energy expenditure | Expressed from baseline up to 600 minutes post-meal | 
| Baseline level and change in heart rate | Heart rate is estimated from wrist-worn activity monitor | Expressed from baseline up to 600 minutes post-meal | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
thermic effect of feeding, thermogenesis, calorimeter, fuel utilization