Sleep QualityCHRONO-MEDNCT07339592
This Trial Examines How Last Meal Composition and Timing Affect Sleep Quality and Circadian Gene Expression Among Medical Residents. Recruitment Not Yet Started; Study Begins Dec 2025 and Ends Dec 2026.
A study testing High-Carbohydrate Last Meal, High-Protein Last Meal and Balanced Standard Dinner in people with Sleep Quality and Meal Timing, run by University of Jordan at 1 site in Jordan.
Trial summary
This randomized controlled trial aims to evaluate the effects of last meal composition and timing on sleep quality and circadian gene expression among medical residents in Jordanian hospitals. Sleep disturbances are common in this population due to long working hours, high stress, and irregular eating schedules. Read more about this study
- Who is it for?
- Ages 25 years and olderHealthy volunteers can take part
- Conditions the study is for
- Sleep Quality, Meal Timing, Circadian Rhythm
- What is being tested?
- High-Carbohydrate Last Meal, High-Protein Last Meal and Balanced Standard Dinner
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 90 participants
- Where
- 1 siteJordan
- Study dates
- 1 Dec 2025to May 2026
- 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 25 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Currently enrolled and working in Jordanian hospitals.
- Not currently following a specific diet or weight-loss program.
- Willing to comply with study protocol and intervention meals for two weeks. Provide written informed consent before participation.
Who cannot join
- Presence of any chronic medical condition (e.g., diabetes, thyroid disorders, gastrointestinal, cardiovascular, or respiratory diseases).
- Diagnosed sleep disorders, such as insomnia, sleep apnea, or restless legs syndrome.
- Mental health disorders (stress, anxiety, or depression diagnosed or medicated).
- Pregnancy or lactation.
- Use of medications or herbal supplements known to affect sleep (e.g., melatonin, chamomile, ashwagandha, lavender).
- Caffeine dependence exceeding moderate levels ( >400 mg caffeine/day).
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: CHRONO-NUTRITION INTERVENTIONS FOR IMPROVING SLEEP QUALITY: The Impact of Last Meal Composition and Timing on Sleep Quality Among Medical Residents at Hospitals
This randomized controlled trial aims to evaluate the effects of last meal composition and timing on sleep quality and circadian gene expression among medical residents in Jordanian hospitals. Sleep disturbances are common in this population due to long working hours, high stress, and irregular eating schedules. Chrono-nutrition, the science of aligning food intake with circadian rhythms, may provide a practical approach to improving sleep and overall well-being.
Participants will be randomly assigned to one of three groups:
Read more
- High-carbohydrate last meal (≈80% of dinner calories from carbohydrates),
- High-protein last meal (≈40-50% of dinner calories from protein),
- Control group consuming a balanced standard meal. Each participant will consume the assigned meal 3-4 hours before bedtime for two weeks. Sleep quality will be measured using the Pittsburgh Sleep Quality Index (PSQI) and smartwatch-derived parameters, while salivary samples collected pre- and post-intervention will be analyzed for CLOCK and BMAL1 gene expression. The study will also include dietary, anthropometric, and physical activity assessments.
This study has been approved by the Institutional Review Board of the University of Jordan (IRB No. 491/2025). Recruitment has not yet started. Enrollment is expected to begin in December 2025, with primary data collection completed by June 2026 and final study completion by December 2026.
- Being tested
- High-Carbohydrate Last Meal, High-Protein Last Meal, Balanced Standard Dinner
- Medical subject headings
- Sleep Initiation and Maintenance Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High-Carbohydrate Last MealDietary supplement
Dinner ≈30% daily kcal; ~80% carb; taken 3-4 h before sleep for 2 weeks
High-Protein Last MealDietary supplement
Dinner ≈30% daily kcal; ~38-54% protein; 3-4 h before sleep for 2 weeks.
Balanced Standard DinnerDietary supplement
Standard macronutrient distribution; same timing (3-4h pre-sleep) and 2-week duration.
| Study group | Role | What they receive |
|---|---|---|
| High-Carbohydrate Last Meal | Experimental | Dinner ≈30% of daily kcal; ~80% of dinner kcal from carbs; consumed 3-4 h before sleep for 2 weeks. Receives: Dietary Supplement: High-Carbohydrate Last Meal |
| High-Protein Last Meal | Experimental | ≈30% of daily kcal; ~38-54% of dinner kcal from protein; consumed 3-4 h before sleep for 2 weeks. Receives: Dietary Supplement: High-Protein Last Meal |
| Balanced Standard last meal | Active comparator | Standard balanced dinner (per usual guidelines), same timing (3-4 h pre-sleep) and 2 weeks duration. Receives: Dietary Supplement: Balanced Standard Dinner |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Sleep Quality (PSQI Global Score)
Sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI) before and after the 2-week intervention. The PSQI total score (0-21) will quantify subjective sleep quality; higher scores indicate poorer sleep
Measured: Baseline and 2 weeks post-intervention
Secondary outcomes (6)
Change in CLOCK Gene Expression
CLOCK mRNA expression will be measured in salivary samples collected pre- and post-intervention using RT-PCR. Relative quantification (ΔCt method) will determine expression changes.
Measured: Baseline and 2 weeks post-intervention
Change in BMAL-1 Gene Expression
BMAL-1 mRNA levels will be analyzed in the same saliva samples via real-time PCR. Changes will be compared across meal groups.
Measured: Baseline and 2 weeks post-intervention
Change in Total Sleep Duration
Total sleep duration will be objectively measured using smartwatch data and expressed as average nightly sleep duration.
Unit of Measure: Minutes per night
Measured: 1 week baseline and 2 weeks during intervention
Change in Sleep Efficiency
Sleep efficiency will be calculated as the percentage of total sleep time divided by time in bed using smartwatch data.
Unit of Measure: Percentage (%)
Measured: 1 week baseline and 2 weeks during intervention
Change in Sleep Stage Distribution
Sleep stage distribution (light, deep, and REM sleep) will be assessed using smartwatch data and expressed as percentage of total sleep time.
Unit of Measure: Percentage (%)
Measured: 1 week baseline and 2 weeks during intervention
Change in Average Heart Rate During Sleep
Average heart rate during sleep will be measured using smartwatch data. Unit of Measure: Beats per minute (bpm)
Measured: 1 week baseline and 2 weeks during intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Jan 2026
- Study start1 Dec 2025
- Primary completionJan 2026 (estimated)
- Study completionMay 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sleep QualityStudies 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 90 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Jordan
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Hadeel Ali Ghazzawi, University of Jordan
- Investigators
- Hadeel A Ghazzawi, professor, Principal investigator, The University of Jordan School of Agriculture
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07339592
- Sponsor's protocol ID
- University of Jordan 491/2025
- Acronym
- CHRONO-MED
- Status last verified
- Jan 2026
- First submitted
- 16 Dec 2025
- Last updated
- 14 Jan 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 14 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- CHRONO-NUTRITION INTERVENTIONS FOR IMPROVING SLEEP QUALITY: The Impact of Last Meal Composition and Timing on Sleep Quality Among Medical Residents at Hospitals
- ClinicalTrials.gov ID
- NCT07339592
- Acronym / sponsor ID
- CHRONO-MED / University of Jordan 491/2025
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 90 participants (estimated)
- Lead sponsor
- University of JordanUniversity, hospital or other
- Study start
- 1 Dec 2025 (actual)
- Primary completion
- Jan 2026 (estimated)
- Study completion
- May 2026 (estimated)
- First posted
- 14 Jan 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.
This randomized controlled trial aims to evaluate the effects of last meal composition and timing on sleep quality and circadian gene expression among medical residents in Jordanian hospitals. Sleep disturbances are common in this population due to long working hours, high stress, and irregular eating schedules. Chrono-nutrition, the science of aligning food intake with circadian rhythms, may provide a practical approach to improving sleep and overall well-being.
Participants will be randomly assigned to one of three groups:
- High-carbohydrate last meal (≈80% of dinner calories from carbohydrates),
- High-protein last meal (≈40-50% of dinner calories from protein),
- Control group consuming a balanced standard meal. Each participant will consume the assigned meal 3-4 hours before bedtime for two weeks. Sleep quality will be measured using the Pittsburgh Sleep Quality Index (PSQI) and smartwatch-derived parameters, while salivary samples collected pre- and post-intervention will be analyzed for CLOCK and BMAL1 gene expression. The study will also include dietary, anthropometric, and physical activity assessments.
This study has been approved by the Institutional Review Board of the University of Jordan (IRB No. 491/2025). Recruitment has not yet started. Enrollment is expected to begin in December 2025, with primary data collection completed by June 2026 and final study completion by December 2026.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| High-Carbohydrate Last Meal | Experimental | Dietary Supplement: High-Carbohydrate Last MealDinner ≈30% of daily kcal; ~80% of dinner kcal from carbs; consumed 3-4 h before sleep for 2 weeks. |
| High-Protein Last Meal | Experimental | Dietary Supplement: High-Protein Last Meal≈30% of daily kcal; ~38-54% of dinner kcal from protein; consumed 3-4 h before sleep for 2 weeks. |
| Balanced Standard last meal | Active comparator | Dietary Supplement: Balanced Standard DinnerStandard balanced dinner (per usual guidelines), same timing (3-4 h pre-sleep) and 2 weeks duration. |
Who may qualify
- Ages
- 25 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Currently enrolled and working in Jordanian hospitals.
- Not currently following a specific diet or weight-loss program.
- Willing to comply with study protocol and intervention meals for two weeks. Provide written informed consent before participation.
Key exclusion criteria (6 listed)
- Presence of any chronic medical condition (e.g., diabetes, thyroid disorders, gastrointestinal, cardiovascular, or respiratory diseases).
- Diagnosed sleep disorders, such as insomnia, sleep apnea, or restless legs syndrome.
- Mental health disorders (stress, anxiety, or depression diagnosed or medicated).
- Pregnancy or lactation.
- Use of medications or herbal supplements known to affect sleep (e.g., melatonin, chamomile, ashwagandha, lavender).
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 |
|---|---|---|
| High-Carbohydrate Last MealDinner ≈30% daily kcal; ~80% carb; taken 3-4 h before sleep for 2 weeks | Dietary supplement | High-Carbohydrate Last Meal |
| High-Protein Last MealDinner ≈30% daily kcal; ~38-54% protein; 3-4 h before sleep for 2 weeks. | Dietary supplement | High-Protein Last Meal |
| Balanced Standard DinnerStandard macronutrient distribution; same timing (3-4h pre-sleep) and 2-week duration. | Dietary supplement | Balanced Standard last meal |
Primary outcome
Change in Sleep Quality (PSQI Global Score)
Time frame: Baseline and 2 weeks post-intervention
Sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI) before and after the 2-week intervention. The PSQI total score (0-21) will quantify subjective sleep quality; higher scores indicate poorer sleep
6 secondary outcomes
Change in CLOCK Gene Expression
Time frame: Baseline and 2 weeks post-intervention
Change in BMAL-1 Gene Expression
Time frame: Baseline and 2 weeks post-intervention
Change in Total Sleep Duration
Time frame: 1 week baseline and 2 weeks during intervention
Change in Sleep Efficiency
Time frame: 1 week baseline and 2 weeks during intervention
Change in Sleep Stage Distribution
Time frame: 1 week baseline and 2 weeks during intervention
Change in Average Heart Rate During Sleep
Time frame: 1 week baseline and 2 weeks during intervention
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 14 Jan 2026.
- Individual participant dataSharing planned: No
Related trials for Sleep Quality
Enrolling by invitation
Physical Activity Interventions for Sleep Improvement and Sedative-Hypnotic Reduction in Middle-Aged and Older Adults: Investigating the Role of Sarcopenia
Insomnia Chronic, Hypnotics and Sedatives
Not yet recruiting
CannaRiver CBD Calm for Anxiety, Sleep, and Well-Being in Adults With Generalized Anxiety Disorder
Generalized Anxiety Disorder
Recruiting
Hemodynamics After Resistance Training
Perimenopause
Not yet recruitingPhase 2
Lemborexant on Perioperative Sleep Quality in Patients With Brain Tumor Undergoing Surgery
Brain Neoplasms, Sleep Initiation and Maintenance Disorders
Not yet recruitingPhase 2
Lemborexant on Perioperative Sleep Quality in Patients With Parkinson's Disease Undergoing Deep Brain Stimulation
Parkinson Disease (PD), Sleep Initiation and Maintenance Disorders
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.
Hadeel A Ghazzawi, professor principal investigator
The University of Jordan School of Agriculture
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing High-Carbohydrate Last Meal, High-Protein Last Meal and Balanced Standard Dinner in people with Sleep Quality and Meal Timing, run by University of Jordan at 1 site in Jordan.
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 3 inclusion and 6 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: enrolling by invitation, as of the sponsor's last update on 14 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 Jordan. 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?
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?
Change in Sleep Quality (PSQI Global Score) (time frame: Baseline and 2 weeks post-intervention). 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 14 Jan 2026.