Energy Supply; Deficiency, SevereNCT04910724
Effects of Varying Energy Deficits on Protein Turnover at Rest and Carbohydrate Oxidation During Steady-state Exercise
A study testing Energy Deficit in people with Energy Supply; Deficiency, Severe and Energy Supply; Deficiency, run by United States Army Research Institute of Environmental Medicine at 1 site in United States.
Trial summary
This randomized, parallel study will examine the effects of energy balance and varying magnitudes of energy deficit on 1) the protein kinetic responses to consuming high quality protein and 2) carbohydrate oxidation during steady-state exercise. Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Energy Supply; Deficiency, Severe, Energy Supply; Deficiency, Stress, Physiological
- What is being tested?
- Energy Deficit
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteUnited States
- Study dates
- 16 Aug 2022to 7 Mar 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Men and women aged 18 - 35 years
- Body mass index < 30.0 kg/m2
- Weight stable for the past 2 months (± ~2.27 kg)
- Healthy without evidence of chronic illness or musculoskeletal injury as determined by the US Army Research Institute of Environmental Medicine Office of Medical Support and Oversight (OMSO) or home duty station medical support
- Routinely participate in aerobic and/or resistance exercise at least 2 days per week defined by self-report for previous 6 months
- Willing to refrain from taking any nonsteroidal anti-inflammatory drugs (e.g., aspirin, Advil®, Aleve®, Naprosyn®), or any other aspirin-containing product for 10 days before the first muscle biopsy and at least 5 days after completing the last muscle biopsy
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- Willing to refrain from alcohol, smoking/using any nicotine product (includes e-cigarettes, vaping, chewing tobacco), caffeine, and dietary supplements during the intervention periods of the study
- Supervisor approval for federal civilian employees and non-Natick Soldier Systems Center Human Research Volunteer (HRV) active duty military personnel
- Females must have normal menstrual cycles between 26-32 days in duration; 5 menstrual cycles within the past 6 months; or able to provide documentation of oral/hormonal contraceptive use which contains low-dose estrogen/progesterone to maintain continuous levels throughout the 28-day cycle (i.e., no placebos)
Who cannot join
- Metabolic or cardiovascular abnormalities, gastrointestinal disorders (e.g., kidney disease, diabetes, cardiovascular disease, etc.)
- Significantly abnormal blood clotting as determined by OMSO or home duty station medical support
- History of complications with lidocaine
- Present condition of alcoholism, anabolic steroid use, or other substance abuse issues as determined by OMSO or home duty station medical support
- Blood donation within 8-wk of beginning the study
- Pregnant, trying to become pregnant, and/or breastfeeding (results of urine pregnancy test and self-report for breastfeeding will be obtained before body composition testing)
- Unwilling or unable to consume study diets or foods provided due to personal preference, dietary restrictions, and/or food allergies
- Unwilling or unable to adhere to study physical restrictions
Trial locations and contacts
1 site in 1 country.
United States1 site
US Army Research Institute of Environmental Medicine
Natick, Massachusetts, 01760
About this study
This randomized, parallel study will examine the effects of energy balance and varying magnitudes of energy deficit on 1) the protein kinetic responses to consuming high quality protein and 2) carbohydrate oxidation during steady-state exercise. Healthy adults, representative of active duty military personnel, will complete a 2 d energy balance phase followed by a randomly assigned, 5 d energy deficit phase (n=15 per group; 20%, 40% and 60% energy deficit). At the end of each energy phase the effects of energy balance and energy deficit severity on resting postabsorptive (fasting) and postprandial (after consuming ~34 g protein) muscle protein synthesis (MPS) and whole-body protein synthesis, breakdown, and balance (synthesis - breakdown) will be determined. On the next day, the effects energy balance and energy deficit severity on carbohydrate oxidation during steady-state exercise will be determined. Primary study procedures include anthropometric and body composition measures, resting metabolic rate measures, aerobic exercise, tightly controlled diet and exercise interventions, repeated blood sampling, stable isotope infusion, stable isotope ingestion, and percutaneous muscle biopsies. The following hypotheses will be tested: 1) Δ (postprandial - postabsorptive) MPS and Δ whole-body protein balance at rest will progressively decrease as magnitude of energy deficit increases and 2) exogenous carbohydrate oxidation will be higher and endogenous carbohydrate oxidation will be lower during steady-state exercise as magnitude of energy deficit increases.
- Being tested
- Energy Deficit
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Energy DeficitOther
A combination of individualized exercise performed on a cycle ergometer and individualized dietary prescriptions will be used to achieve energy balance or the assigned energy deficits throughout the controlled feeding and testing periods
| Study group | Role | What they receive |
|---|---|---|
| 20% Energy Deficit | Experimental | Energy Deficit equal to 20% total daily energy requirements. Receives: Other: Energy Deficit |
| 40% Energy Deficit | Experimental | Energy Deficit equal to 40% total daily energy requirements. Receives: Other: Energy Deficit |
| 60% Energy Deficit | Experimental | Energy Deficit equal to 60% total daily energy requirements. Receives: Other: Energy Deficit |
What is being measured
The primary outcome is the main question the study is designed to answer.
Whole-body protein balance
Determined using L-[1-13C]-leucine stable isotope.
Measured: 2 days
Muscle Protein Synthesis
Determined using L-[ring-2H5]-phenylalanine stable isotope.
Measured: 2 days
Carbohydrate Oxidation during Steady-state Exercise
Determined using U-13C-glucose stable isotope.
Measured: 2 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Jun 2021
- Study start16 Aug 2022
- Primary completion7 Mar 2024
- Study completion7 Mar 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Energy Supply; Deficiency, SevereStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Randomized, parallel study comparing the effects of 3 magnitudes of energy deficit.
- Masking
- None (open label)
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- United States Army Research Institute of Environmental Medicine
- Sponsor type
- US federal agency
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04910724
- Sponsor's protocol ID
- 21-09HC
- Status last verified
- Jan 2026
- First submitted
- 27 May 2021
- Last updated
- 21 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Varying Energy Deficits on Protein Turnover at Rest and Carbohydrate Oxidation During Steady-state Exercise
- ClinicalTrials.gov ID
- NCT04910724
- Acronym / sponsor ID
- 21-09HC
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- United States Army Research Institute of Environmental MedicineUS federal agency
- Study start
- 16 Aug 2022 (actual)
- Primary completion
- 7 Mar 2024 (actual)
- Study completion
- 7 Mar 2024 (actual)
- First posted
- 2 Jun 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This randomized, parallel study will examine the effects of energy balance and varying magnitudes of energy deficit on 1) the protein kinetic responses to consuming high quality protein and 2) carbohydrate oxidation during steady-state exercise. Healthy adults, representative of active duty military personnel, will complete a 2 d energy balance phase followed by a randomly assigned, 5 d energy deficit phase (n=15 per group; 20%, 40% and 60% energy deficit). At the end of each energy phase the effects of energy balance and energy deficit severity on resting postabsorptive (fasting) and postprandial (after consuming ~34 g protein) muscle protein synthesis (MPS) and whole-body protein synthesis, breakdown, and balance (synthesis - breakdown) will be determined. On the next day, the effects energy balance and energy deficit severity on carbohydrate oxidation during steady-state exercise will be determined. Primary study procedures include anthropometric and body composition measures, resting metabolic rate measures, aerobic exercise, tightly controlled diet and exercise interventions, repeated blood sampling, stable isotope infusion, stable isotope ingestion, and percutaneous muscle biopsies. The following hypotheses will be tested: 1) Δ (postprandial - postabsorptive) MPS and Δ whole-body protein balance at rest will progressively decrease as magnitude of energy deficit increases and 2) exogenous carbohydrate oxidation will be higher and endogenous carbohydrate oxidation will be lower during steady-state exercise as magnitude of energy deficit increases.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
- Model description
- Randomized, parallel study comparing the effects of 3 magnitudes of energy deficit.
| Arm | Type | Receives |
|---|---|---|
| 20% Energy Deficit | Experimental | Other: Energy DeficitEnergy Deficit equal to 20% total daily energy requirements. |
| 40% Energy Deficit | Experimental | Other: Energy DeficitEnergy Deficit equal to 40% total daily energy requirements. |
| 60% Energy Deficit | Experimental | Other: Energy DeficitEnergy Deficit equal to 60% total daily energy requirements. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (9 listed)
- Men and women aged 18 - 35 years
- Body mass index < 30.0 kg/m2
- Weight stable for the past 2 months (± ~2.27 kg)
- Healthy without evidence of chronic illness or musculoskeletal injury as determined by the US Army Research Institute of Environmental Medicine Office of Medical Support and Oversight (OMSO) or home duty station medical support
- Routinely participate in aerobic and/or resistance exercise at least 2 days per week defined by self-report for previous 6 months
Key exclusion criteria (8 listed)
- Metabolic or cardiovascular abnormalities, gastrointestinal disorders (e.g., kidney disease, diabetes, cardiovascular disease, etc.)
- Significantly abnormal blood clotting as determined by OMSO or home duty station medical support
- History of complications with lidocaine
- Present condition of alcoholism, anabolic steroid use, or other substance abuse issues as determined by OMSO or home duty station medical support
- Blood donation within 8-wk of beginning the study
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Energy DeficitA combination of individualized exercise performed on a cycle ergometer and individualized dietary prescriptions will be used to achieve energy balance or the assigned energy deficits throughout the controlled feeding and testing periods | Other | 20% Energy Deficit, 40% Energy Deficit, 60% Energy Deficit |
Primary outcome
Whole-body protein balance
Time frame: 2 days
Determined using L-[1-13C]-leucine stable isotope.
Muscle Protein Synthesis
Time frame: 2 days
Determined using L-[ring-2H5]-phenylalanine stable isotope.
Carbohydrate Oxidation during Steady-state Exercise
Time frame: 2 days
Determined using U-13C-glucose stable isotope.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Jan 2026.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Energy Deficit in people with Energy Supply; Deficiency, Severe and Energy Supply; Deficiency, run by United States Army Research Institute of Environmental Medicine at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 21 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Whole-body protein balance (time frame: 2 days). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Jan 2026.