Nighttime synchronization of eating and your circadian clock

Nighttime Synchrony of Your Nutrition and Circadian Health: The N-Sync Study

This trial will test whether changing light exposure and when you eat during short sleep periods changes metabolism in healthy adults aged 18–35 who normally sleep 7–9 hours per night.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 120 (estimated)
• Ages: 18 Years to 35 Years
• Sex: All
• Sponsor: University of Utah (Academic / other)
• Locations: 1 site (Salt Lake City, Utah)
• Trial ID: NCT07329283 on ClinicalTrials.gov

What this trial studies

This randomized, in-lab crossover trial has each participant complete three 5-night sleep-restriction conditions with different timing of light and food, separated by ambulatory baseline monitoring. Participants will follow one of two arm orders so everyone completes all three conditions (central and peripheral alignment, central clock misalignment, or peripheral misalignment). After each sleep-restriction segment participants undergo an intravenous glucose tolerance test and a constant routine protocol to map 24-hour metabolic rhythms. The full protocol includes 6–8 clinic visits, three overnight stays, surveys, and medical tests over about 4–6 months.

Who should consider this trial

Good fit: Ideal candidates are healthy men and women age 18–35 with BMI 18.5–24.9 kg/m2 who habitually sleep 7–9 hours per night and have no major medical, psychiatric, or sleep disorders.

Not a fit: People with diabetes, significant organ disease, BMI outside the specified range, recent shift work, pregnancy, smoking, heavy alcohol use, or recent medication use are excluded and are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, the findings could lead to practical timing recommendations for light exposure and meals that protect metabolism during periods of restricted sleep.

How similar studies have performed: Prior circadian and meal-timing studies have shown that misaligned light and food timing can change metabolic measures, but testing these effects specifically during controlled sleep restriction in a three-arm crossover format is relatively novel.

Eligibility criteria

Inclusion Criteria:

1. Age: 18-35 years old; equal numbers of men and women
2. Body Mass Index (BMI): 18.5-24.9 kg/m2
3. Sleep Habits: habitual self-reported average total sleep time (TST) 7-9 hours per night for prior 6 months

Exclusion Criteria:

1. Clinically diagnosed sleep disorder or apnea hypopnea index (AHI) ≥5
2. Evidence of significant organ system dysfunction or disease (e.g., heart disease, diabetes)
3. Fasting plasma glucose ≥100 mg/dL
4. Major psychiatric illness (e.g., major depressive disorder)
5. Cancer that has been in remission less than 5 years
6. History of shift-work in prior year
7. Weight change \>5% of body weight over prior six months
8. Currently following a weight-loss program
9. Menopause
10. Pregnant/nursing
11. Greater than 5-day variation in menstrual cycle length month-to-month
12. Currently smoking
13. Alcohol intake \>14 drinks/week or \>3 drinks/day.
14. Use of prescription medications (except oral contraceptives) within one month prior to or during in-lab visits.
15. Consumption of illegal drugs or \>500mg per day of caffeine.

Where this trial is running

Salt Lake City, Utah

• College of Health Research Complex - University of Utah, Salt Lake City 84112 — Salt Lake City, Utah, United States (Recruiting)

Study contacts

• Principal investigator: Christopher Depner, PhD — University of Utah
• Study coordinator: Victoria Miranda, MS

Conditions Sleep; Metabolism Changes; Circadian Rhythm; Lifestyle Factors; Sleep Hygiene; Sleep Hygiene, Inadequate; Sleep Deprivation; Insufficient Sleep