CompletedNot Applicable

Effects of Caffeine in Hydration and Energy Metabolism

Portugal30 participantsStarted 2010-01

Plain-language summary

The main purposes of this randomized cross-over trial are to characterize and compare the effects of a moderate dose of caffeine intake in healthy physically active males on hydration and energy metabolism specifically: 1. Total body water and its compartments (intracellular and extracellular) assessed by by dilution techniques, and hydration state by urine specific gravity; 2. Total energy expenditure by double labeled water, resting energy expenditure by indirect calorimetry, and physical activity energy expenditure; 3. Energy expenditure in physical activity of daily living, in particular duration and intensity of activity. 4. If the changes occurred between placebo and caffeine ingestion on the main outcomes were dependent on specific covariates, namely body composition and dietary intake.

Who can participate

Age range

18 Years – 39 Years

Sex

MALE

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * male * aged 18-39 years old * body mass index between 18.5 and 29.9 kg/m2 * Subjects had to be free of any major disease with a general healthy status warranted Exclusion Criteria: * Smokers * taking medication or dietary supplements that may interfere with hydration status * body composition or energy expenditure regulation * Caffeine consumption \> 100 mg/day

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Changes in Total body water (TBW), extracellular water (ECW), intracellular water (ICW), and hydration status from baseline to each experimental condition (Placebo or Caffeine)

Timeframe: day 0, day 4, and day 11

Changes in total energy expenditure (TEE), resting energy expenditure (REE), and physical activity energy expenditure (PAEE) between each experimental conditions (placebo or caffeine)

Timeframe: Day 4 and day 11

Changes in daily time spent in sedentary activities (DTSS), light activities (DTSL), moderate activities (DTSM), and vigorous activities (DTSV) between each experimental conditions (placebo or caffeine)

Timeframe: day 4 and day 11

Trial details

NCT IDNCT01477294

SponsorTechnical University of Lisbon

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2010-03

View on ClinicalTrials.gov More Caffeine trials