Water Consumption, Hydration and Resting Energy Expenditure

Study Overview
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Brief Summary
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A randomized, cross over study will assess the effects of ingestion of high and low volumes of water on REE over 90 minutes. The high volume of water 500ml and the low volume of water 250ml. Participants will be computer randomized to determine which volume of water to receive first. Participants will arrive at the Nutrition Assessment Laboratory between 7:00 and 7:30am following a 9 hour overnight fast. Participants will be instructed not to consume any food or drink after 10pm the night before the assessment. Participants will also be asked to abstain from alcohol and caffeine for 3 days before the assessment. After verification of eligibility, baseline REE will be measured for 30 minutes followed by administration of first assigned dose of water. REE will be monitored for the next 90 minutes. Blood pressure and heart rate will also be monitored, simultaneously to REE. After a 7-10 day washout period, participants will return for their second test day where the second dose of water will be administered. A 7-10 day washout period was selected to allow participants time to resume normal diet and hydration between visits.

Official Title
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Water Consumption, Hydration and Resting Energy Expenditure

Conditions
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Hydration and Resting Metabolism

Intervention / Treatment
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* Other: water intake


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-39 years of age Generally Healthy men and women BMI 18.5-28 Willing to abstain from caffeine for 3 days prior to testing Able to provide written consent in English Ability to communicate in English (oral and written Exclusion Criteria: <18 or >39 years BMI < 18.5 or >28 Pregnant or Nursing Taking prescribed or over the counter medication affecting fluid balance or metabolism Suffers from hepatic, renal, pulmonary, endocrine or hematological disease Performs more than 3 hours a week of strenuous exercise Consumes, on average, more than 2 alcoholic beverages per day More than 5kg of weight change over the past 6 months Claustrophobic

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 39 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 250ml<br> | Other: water intake<br>* After an overnight fast participants' RMR will be measured by indirect calorimetry for 30 minutes after which either a low (250ml) or high (500ml) dose of water will be consumed followed by an additional 90 minutes of indirect calorimetry. The test day will be repeated after 7-10 days with the second dose of water. The order in which the dose of water will be consumed will be randomized<br>|
| Active Comparator: 500ml<br> | Other: water intake<br>* After an overnight fast participants' RMR will be measured by indirect calorimetry for 30 minutes after which either a low (250ml) or high (500ml) dose of water will be consumed followed by an additional 90 minutes of indirect calorimetry. The test day will be repeated after 7-10 days with the second dose of water. The order in which the dose of water will be consumed will be randomized<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Resting Metabolic Rate (RMR) | Resting Metabolic Rate after water intake | 90 minutes | 
| Substrate oxidation | Change in substrate oxidation after water intake | 90 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| blood pressure |  | 90 minutes | 
| heart rate |  | 90 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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RMR, hydration, substrate oxidation