Energy Deficiency Due to Short-term FastingNCT07651800
Energy Deficiency on Hormones in Contraceptive Users
A study testing Energy Deficiency of approximately ~250 kcal/day in people with Energy Deficiency Due to Short-term Fasting and Hormonal Contraception, run by University of Southern California at 1 site in United States.
Trial summary
The purpose of the present study is to characterize the endocrine and metabolic responses to a modest, short-term energy deficiency (~250 kcal/day) across the menstrual cycle in recreationally active women using different contraceptive methods (oral contraceptive, hormonal IUD, and non-hormonal IUD). Read more about this study
- Who is it for?
- Ages 18 to 35 years, women only
- Conditions the study is for
- Energy Deficiency Due to Short-term Fasting, Hormonal Contraception
- What is being tested?
- Energy Deficiency of approximately ~250 kcal/day
- Type of treatment
- Pill or oral medicine, Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteUnited States
- Study dates
- Sep 2026to Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- Female, aged 18-35 years
- Recreationally active (engaging in structured exercise between 8-15 hours per week)
- BMI of 18.5-29.9 as a BMI below or above these cut points results in highly varied menstrual cycle lengths17
- Not currently experiencing an eating disorder or disordered eating, or having a diagnosed eating disorder in the last 3 years
- Non-pregnant or planning to become pregnant
- Medically free from chronic diseases
Show all 15Show fewer
- Currently using one of the following contraceptive methods for ≥3 months:
- Monophasic oral contraceptive
- Hormonal intrauterine device (H-IUD)
- Copper intrauterine device
- Weight stable (no weight change >5% body weight within the past 3 months)
- Weight greater than or equal to 110 lbs
- Not suffering from known gynecological disease (i.e., PCOS, endometriosis, etc.) that may influence menstrual cycle regularity
- Willing and able to maintain current exercise habits throughout the study
- Willing to follow study dietary guidance to achieve a ~250 kcal/day energy deficit during Cycle 2
Who cannot join
- Amenorrhea or oligomenorrhea
- Perimenopausal or menopausal
- Currently pregnant, planning pregnancy, or breastfeeding
- Use of hormonal contraception other than monophasic oral contraceptives or hormonal IUD (implant, nuvaring, etc.)
- Initiation or change of contraceptive method within the past 3 months
- Diagnosis of polycystic ovary syndrome (PCOS), endometriosis, hypothalamic amenorrhea, or other known reproductive endocrine disorder
Show all 14Show fewer
- Current or history of eating disorder or clinically diagnosed disordered eating
- Current participation in intentional weight loss or weight gain program
- Use of medications known to affect metabolism or hormone levels (e.g., systemic corticosteroids, thyroid medications, insulin, GLP-1 agonists)
- Known metabolic, cardiovascular, renal, hepatic, or endocrine disease
- Musculoskeletal injury limiting exercise participation within the past 3 months
- Smoking or nicotine use
- Contraindications to DXA scanning (e.g., pregnancy, recent high-radiation diagnostic imaging exceeding institutional limits)
- Inability or unwillingness to comply with study procedures
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
University of Southern California Health Sciences Campus Center for Health Professions
Los Angeles, California, 90033
Emily Lundstrom, PhD, 3234422180, elundstr@usc.edu
About this study
Official title: Effects of a Modest Energy Deficit on Reproductive Hormones Across the Menstrual Cycle in Contraceptive Users
The purpose of the present study is to characterize the endocrine and metabolic responses to a modest, short-term energy deficiency (~250 kcal/day) across the menstrual cycle in recreationally active women using different contraceptive methods (oral contraceptive, hormonal IUD, and non-hormonal IUD). This study will leverage daily urinary hormone metabolite tracking and comprehensive metabolic assessments, providing foundational data addressing an important and previously unexamined interaction between energy availability and hormonal regulation in contraceptive users.
Read the detailed description
The purpose of the present study is to characterize the endocrine and metabolic responses to a modest, short-term energy deficiency (~250 kcal/day) across the menstrual cycle in recreationally active women using different contraceptive methods. The investigators will be focusing on oral contraceptive users, hormonal IUD, and non-hormonal (i.e., copper IUD). Daily urinary hormone metabolite tracking and comprehensive metabolic assessments (i.e., resting metabolic rate, body composition via DXA, exercise logs, and energy intake) will be used to provide foundational data addressing an important and previously unexamined interaction between energy availability and hormonal regulation in contraceptive users.
Based on evidence that female reproductive hormones are sensitive to energetic stress, that estrogen plays a central role in regulating metabolism and endocrine function, and that hormonal contraceptive methods differentially alter endogenous hormone profiles, the central hypothesis of this study is that a modest, controlled energy deficiency (~250 kcal/day) will alter reproductive hormone profiles across the menstrual cycle in recreationally active women using contraceptives. Specifically, it is hypothesized that changes in urinary reproductive hormone measures will be detectable during an energy-deficient cycle compared to a baseline cycle, and that the magnitude and pattern of these changes will differ by contraceptive type, with hormonal oral contraceptive users demonstrating a different hormonal response to energy deficiency than copper or hormonal intrauterine device users.
A secondary hypothesis is that energy deficiency-induced hormonal changes will be associated with alterations in resting metabolic rate and body composition, and that these associations may be moderated by exercise energy expenditure and perceived stress. Collectively, these hypotheses are grounded in prior research demonstrating hormonal sensitivity to energetic perturbations and the distinct endocrine environments created by different contraceptive methods, while addressing a clear gap in the current literature regarding the interaction between energy availability and hormonal regulation in contraceptive users.
- Being tested
- Energy Deficiency of approximately ~250 kcal/day
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Energy Deficiency of approximately ~250 kcal/dayBehavioural
Following an initial baseline menstrual cycle, participants will be subjected to at least two weeks of a ~250 kcal/day energy deficit monitored through daily diet tracking.
| Study group | Role | What they receive |
|---|---|---|
| Monophasic low dose oral contraceptive users | Experimental | The first group will be only individuals who are on a low dose, monophasic oral contraceptive that they have elected to be on prior to enrollment in the study. They will undergo a baseline monitoring menstrual cycle that will include daily urinary hormone monitoring, baseline metabolic and body composition assessments, and assessment of baseline energy expenditure and energy intake. During a two week washout week, participants will not be monitoring hormones, but will be subjected to a ~250 kcal/day energy deficit. Following this imposed energy deficiency, they will resume urinary metabolite testing and exercise intake and expenditure tracking. They will undergo this monitoring for a final menstrual cycle and metabolic and body composition assessments, and assessment of energy expenditure and energy intake. Receives: Behavioral: Energy Deficiency of approximately ~250 kcal/day |
| Hormonal IUD | Experimental | The second group will be only individuals who have a hormonal IUD that they have elected to be on prior to enrollment in the study. They will undergo a baseline monitoring menstrual cycle that will include daily urinary hormone monitoring, baseline metabolic and body composition assessments, and assessment of baseline energy expenditure and energy intake. During a two week washout week, participants will not be monitoring hormones, but will be subjected to a ~250 kcal/day energy deficit. Following this imposed energy deficiency, they will resume urinary metabolite testing and exercise intake and expenditure tracking. They will undergo this monitoring for a final menstrual cycle and metabolic and body composition assessments, and assessment of energy expenditure and energy intake. Receives: Behavioral: Energy Deficiency of approximately ~250 kcal/day |
| Non-Hormonal (i.e., Copper) IUD | Experimental | The last group will be only individuals who have a non-hormonal/copper IUD that they have elected to be on prior to enrollment in the study. They will undergo a baseline monitoring menstrual cycle that will include daily urinary hormone monitoring, baseline metabolic and body composition assessments, and assessment of baseline energy expenditure and energy intake. During a two week washout week, participants will not be monitoring hormones, but will be subjected to a ~250 kcal/day energy deficit. Following this imposed energy deficiency, they will resume urinary metabolite testing and exercise intake and expenditure tracking. They will undergo this monitoring for a final menstrual cycle and metabolic and body composition assessments, and assessment of energy expenditure and energy intake Receives: Behavioral: Energy Deficiency of approximately ~250 kcal/day |
What is being measured
The primary outcome is the main question the study is designed to answer.
Urinary hormone exposure
Participants will be asked to track daily urine concentrations of estrogen and progesterone throughout a baseline (i.e., non-energy-deficient state) menstrual cycle and a menstrual cycle with an imposed energy deficit. The outcome will compare hormone exposure measured by the urinary concentrations between the two cycles.
Measured: From enrollment to energy deficit menstrual cycle is 3 months/90 days
Secondary outcomes (5)
Estimated versus actual resting metabolic rate
Body composition and estimated metabolic rate will be collected using DXA. The DXA will be measured at baseline and at the conclusion of the energy-deficient menstrual cycle. Resting metabolic rate will be measured via indirect calorimetry testing at baseline, at the beginning of the second monitored (i.e., energy-deficient) menstrual cycle, and at the conclusion of the energy-deficient menstrual cycle. The estimated and actual metabolic rate will be compared as an assessment of energy status. Participants will also be asked to track exercise using a paper log or wearable device to estimate exercise energy expenditure (EEE), and daily intake (EI) will be measured via a paper log or an application. These values will be subtracted (EI-EEE) and normalized to fat-free mass collected via DXA to estimate energy availability.
Measured: From enrollment to completion 90 days/3 months
Eating behaviors and attitudes will be measured using the EDEQ and the Three Factor Eating Questionnaire
The Eating Disorder Examination Questionnaire is a 12 item questionnaire scaled from 0 to 3 (0 being 0 days and 3 being 6 to 7 days) assessing feelings around eating behaviors, body image, and restraint. The Three Factor Eating questionnaire is an 18-question survey that assesses cognitive restraint, emotional eating, and uncontrolled eating on a 4 point Likert scale (0 being never and 3 being at least once a week).
Measured: From enrollment to conclusion 90 days/3 months
Subjective stress levels will measured using the Perceived Stress Scale
The Subjective Stress Scale measures percieved stress through 10 questions about recent stress perceptions on a 0 to 4 Likert scale (0 being never; and 4 being very often).
Measured: From enrollment to conclusion 90 days/3 months
Low Energy Availability Indicators will be assessed using the LEAF-Q
The low energy availability in Females Questionnaire (LEAF-Q) is used to identify female athletes 'at risk' of low energy availability. This questionnaire assesses physiological symptoms associated with LEA, including 25 questions arranged into 3 sections; eating and reproductive assessment, injury assessment, and gastrointestinal symptom assessment. A total score of ≥8 out of 25 questions indicates that the athlete is at risk of LEA. There is a standardized scoring system that varies by question and subquestion.
Measured: From enrollment to conclusion 90 days/3 months
Body composition will be measured using DXA
Dual-energy x-ray absorbtometry will be used to assess body composition including segmental analysis of body fat and lean mass.
Measured: From enrollment to conclusion 90 days/3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jun 2026
- Study startSep 2026 (estimated)
- Primary completionJun 2027 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Energy Deficiency Due to Short-term FastingStudies of the same condition, open and under way.
- More trials run by University of Southern CaliforniaThe sponsor's other registered studies.
- 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
- Screening
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- There will be three groups: oral contraceptive users, hormonal IUD users, and non-hormonal IUD users that will all undergo the same protocol. The first cycle will involve a baseline assessment of urinary hormone metabolites. The second cycle will involve an imposed energy deficiency for at least 2 weeks will continuous hormone monitoring.
- Masking
- None (open label)
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Southern California
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Todd Schroeder, University of Southern California
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07651800
- Sponsor's protocol ID
- HS-26-00204
- Status last verified
- Jun 2026
- First submitted
- 23 Apr 2026
- Last updated
- 16 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 16 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of a Modest Energy Deficit on Reproductive Hormones Across the Menstrual Cycle in Contraceptive Users
- ClinicalTrials.gov ID
- NCT07651800
- Acronym / sponsor ID
- HS-26-00204
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- University of Southern CaliforniaUniversity, hospital or other
- Study start
- Sep 2026 (estimated)
- Primary completion
- Jun 2027 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 16 Jun 2026 (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.
The purpose of the present study is to characterize the endocrine and metabolic responses to a modest, short-term energy deficiency (~250 kcal/day) across the menstrual cycle in recreationally active women using different contraceptive methods (oral contraceptive, hormonal IUD, and non-hormonal IUD). This study will leverage daily urinary hormone metabolite tracking and comprehensive metabolic assessments, providing foundational data addressing an important and previously unexamined interaction between energy availability and hormonal regulation in contraceptive users.
Detailed description
The purpose of the present study is to characterize the endocrine and metabolic responses to a modest, short-term energy deficiency (~250 kcal/day) across the menstrual cycle in recreationally active women using different contraceptive methods. The investigators will be focusing on oral contraceptive users, hormonal IUD, and non-hormonal (i.e., copper IUD). Daily urinary hormone metabolite tracking and comprehensive metabolic assessments (i.e., resting metabolic rate, body composition via DXA, exercise logs, and energy intake) will be used to provide foundational data addressing an important and previously unexamined interaction between energy availability and hormonal regulation in contraceptive users.
Based on evidence that female reproductive hormones are sensitive to energetic stress, that estrogen plays a central role in regulating metabolism and endocrine function, and that hormonal contraceptive methods differentially alter endogenous hormone profiles, the central hypothesis of this study is that a modest, controlled energy deficiency (~250 kcal/day) will alter reproductive hormone profiles across the menstrual cycle in recreationally active women using contraceptives. Specifically, it is hypothesized that changes in urinary reproductive hormone measures will be detectable during an energy-deficient cycle compared to a baseline cycle, and that the magnitude and pattern of these changes will differ by contraceptive type, with hormonal oral contraceptive users demonstrating a different hormonal response to energy deficiency than copper or hormonal intrauterine device users.
A secondary hypothesis is that energy deficiency-induced hormonal changes will be associated with alterations in resting metabolic rate and body composition, and that these associations may be moderated by exercise energy expenditure and perceived stress. Collectively, these hypotheses are grounded in prior research demonstrating hormonal sensitivity to energetic perturbations and the distinct endocrine environments created by different contraceptive methods, while addressing a clear gap in the current literature regarding the interaction between energy availability and hormonal regulation in contraceptive users.
Study design
- Primary purpose
- Screening
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
- Model description
- There will be three groups: oral contraceptive users, hormonal IUD users, and non-hormonal IUD users that will all undergo the same protocol. The first cycle will involve a baseline assessment of urinary hormone metabolites. The second cycle will involve an imposed energy deficiency for at least 2 weeks will continuous hormone monitoring.
| Arm | Type | Receives |
|---|---|---|
| Monophasic low dose oral contraceptive users | Experimental | Behavioral: Energy Deficiency of approximately ~250 kcal/dayThe first group will be only individuals who are on a low dose, monophasic oral contraceptive that they have elected to be on prior to enrollment in the study. They will undergo a baseline monitoring menstrual cycle that will include daily urinary hormone monitoring, baseline metabolic and body composition assessments, and assessment of baseline energy expenditure and energy intake. During a two week washout week, participants will not be monitoring hormones, but will be subjected to a ~250 kcal/day energy deficit. Following this imposed energy deficiency, they will resume urinary metabolite testing and exercise intake and expenditure tracking. They will undergo this monitoring for a final menstrual cycle and metabolic and body composition assessments, and assessment of energy expenditure and energy intake. |
| Hormonal IUD | Experimental | Behavioral: Energy Deficiency of approximately ~250 kcal/dayThe second group will be only individuals who have a hormonal IUD that they have elected to be on prior to enrollment in the study. They will undergo a baseline monitoring menstrual cycle that will include daily urinary hormone monitoring, baseline metabolic and body composition assessments, and assessment of baseline energy expenditure and energy intake. During a two week washout week, participants will not be monitoring hormones, but will be subjected to a ~250 kcal/day energy deficit. Following this imposed energy deficiency, they will resume urinary metabolite testing and exercise intake and expenditure tracking. They will undergo this monitoring for a final menstrual cycle and metabolic and body composition assessments, and assessment of energy expenditure and energy intake. |
| Non-Hormonal (i.e., Copper) IUD | Experimental | Behavioral: Energy Deficiency of approximately ~250 kcal/dayThe last group will be only individuals who have a non-hormonal/copper IUD that they have elected to be on prior to enrollment in the study. They will undergo a baseline monitoring menstrual cycle that will include daily urinary hormone monitoring, baseline metabolic and body composition assessments, and assessment of baseline energy expenditure and energy intake. During a two week washout week, participants will not be monitoring hormones, but will be subjected to a ~250 kcal/day energy deficit. Following this imposed energy deficiency, they will resume urinary metabolite testing and exercise intake and expenditure tracking. They will undergo this monitoring for a final menstrual cycle and metabolic and body composition assessments, and assessment of energy expenditure and energy intake |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (15 listed)
- Female, aged 18-35 years
- Recreationally active (engaging in structured exercise between 8-15 hours per week)
- BMI of 18.5-29.9 as a BMI below or above these cut points results in highly varied menstrual cycle lengths17
- Not currently experiencing an eating disorder or disordered eating, or having a diagnosed eating disorder in the last 3 years
- Non-pregnant or planning to become pregnant
Key exclusion criteria (14 listed)
- Amenorrhea or oligomenorrhea
- Perimenopausal or menopausal
- Currently pregnant, planning pregnancy, or breastfeeding
- Use of hormonal contraception other than monophasic oral contraceptives or hormonal IUD (implant, nuvaring, etc.)
- Initiation or change of contraceptive method within the past 3 months
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 Deficiency of approximately ~250 kcal/dayFollowing an initial baseline menstrual cycle, participants will be subjected to at least two weeks of a ~250 kcal/day energy deficit monitored through daily diet tracking. | Behavioural | Hormonal IUD, Monophasic low dose oral contraceptive users, Non-Hormonal (i.e., Copper) IUD |
Primary outcome
Urinary hormone exposure
Time frame: From enrollment to energy deficit menstrual cycle is 3 months/90 days
Participants will be asked to track daily urine concentrations of estrogen and progesterone throughout a baseline (i.e., non-energy-deficient state) menstrual cycle and a menstrual cycle with an imposed energy deficit. The outcome will compare hormone exposure measured by the urinary concentrations between the two cycles.
5 secondary outcomes
Estimated versus actual resting metabolic rate
Time frame: From enrollment to completion 90 days/3 months
Eating behaviors and attitudes will be measured using the EDEQ and the Three Factor Eating Questionnaire
Time frame: From enrollment to conclusion 90 days/3 months
Subjective stress levels will measured using the Perceived Stress Scale
Time frame: From enrollment to conclusion 90 days/3 months
Low Energy Availability Indicators will be assessed using the LEAF-Q
Time frame: From enrollment to conclusion 90 days/3 months
Body composition will be measured using DXA
Time frame: From enrollment to conclusion 90 days/3 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Jun 2026.
- Individual participant dataSharing planned: No
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.
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 Deficiency of approximately ~250 kcal/day in people with Energy Deficiency Due to Short-term Fasting and Hormonal Contraception, run by University of Southern California 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 15 inclusion and 14 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: opening soon, as of the sponsor's last update on 16 Jun 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Emily Lundstrom, PhD (3234422180, elundstr@usc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Urinary hormone exposure (time frame: From enrollment to energy deficit menstrual cycle is 3 months/90 days). 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 16 Jun 2026.