Dietary Impact on Sleep, Rhythms and Related Physiology

NCT ID: NCT07138313

Last Updated: 2025-08-22

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 24 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-09-30
• Study Completion Date: 2026-12-15

Brief Summary

Sleep and metabolism are closely interconnected, and emerging evidence suggests that dietary composition may influence both sleep quality and key physiological functions such as glucose regulation, cardiovascular activity, and hormonal signaling. This study aims to investigate how a Western-style unhealthy diet versus a healthier, fiber-rich diet affects objective and subjective sleep measures, 24-hour physiological parameters, and a range of biomarkers related to cardiometabolic, neurodegenerative, and gut microbial function.

Detailed Description

Metabolism is tightly regulated by sleep and interacts bidirectionally with diet. While it is well established that insufficient or disrupted sleep can impair glucose regulation, cardiovascular function, and promote unhealthy eating behaviors that promote cardiometabolic disease, less is known about how different dietary patterns impact subjective and objective sleep parameters, as well as related physiological systems.

The study will systematically investigate how consumption of an unhealthier "Western" diet, compared to a healthier diet, affects both objective and subjective sleep parameters, as well as 24-hour heart rate and blood pressure profiles, glucose variability, and hormonal and molecular biomarkers.

The study will be conducted as a 2-condition, randomized crossover study, with assessments in the field for about a week, followed by a multi-day stay for measurements under standardized laboratory conditions. Participants will be monitored using polysomnography, and wearable devices, including for continuous glucose and heart rate parameters, with multi-compartment sampling to assess diet-mediated responses across cardiometabolic, neurodegenerative, and microbial pathways. In field and in the lab, biological samples will be collected repeatedly across the day to establish diurnal rhythms.

Cognitive performance, mood, and subjective appetite will also be evaluated. By identifying diet-driven changes in sleep and related physiological functions, this study aims to provide mechanistic insights into how nutrition impacts sleep, cardiometabolic health parameters and molecular pathways.

Conditions

Sleep; Diet Interventions; Circadian Rhythm

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Healthy diet

'Low-fat dietary intervention' to be administered to participants

Group Type: EXPERIMENTAL

Low-fat dietary intervention

Intervention Type: OTHER

Low-fat diet for approximately 1 week, preceding in-lab study period (approximately 2 days) under standardized conditions (total dietary exposure up to 9-10 days).

Unhealthier diet

'High-fat dietary intervention' to be administered to participants

Group Type: EXPERIMENTAL

High-fat dietary intervention

Intervention Type: OTHER

High-fat diet for approximately 1 week, preceding in-lab study period (approximately 2 days) under standardized conditions (total dietary exposure up to 9-10 days).

Interventions

Low-fat dietary intervention

Low-fat diet for approximately 1 week, preceding in-lab study period (approximately 2 days) under standardized conditions (total dietary exposure up to 9-10 days).

Intervention Type: OTHER

High-fat dietary intervention

High-fat diet for approximately 1 week, preceding in-lab study period (approximately 2 days) under standardized conditions (total dietary exposure up to 9-10 days).

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Age 18-32 yr
• Healthy (self-reported) and not on chronic medication
• BMI 18-27 kg/m2 (and waist circumference <102 cm), and weight stable (less than 5% body weight change in the past 6 months)
• Non-smoker and non-nicotine user
• Regular sleep-wake pattern, with sleep duration of 7-9.25 hrs per night
• Regular exercise habits the last 2 months
• Regular daily meal pattern with 3 main meals

Exclusion Criteria

• Major or chronic illness, e.g. diabetes, renal disease or inflammatory bowel disease
• Current or history of endocrine or metabolic disorders
• Psychiatric or neurological disorders (e.g. bipolar disorder, epilepsy)
• Frequent gastrointestinal symptoms
• Chronic medication
• Any sleep disorder (including recent or chronic symptoms of insomnia)
• Shift work in the preceding three months or for a long duration
• Extreme chronotype or physical activity patterns
• Time travel over two time zones in the preceding month
• Too much weight gain or weight loss in the preceding 6 months (±5% body weight in past 6 months)
• Any issues with or allergies against the provided food items
• Recent major dietary changes or adoption of specific dietary regimens
• Women who are pregnant, breastfeeding, or planning to become pregnant during the study period.
• Use of illicit drugs or substances of abuse

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 32 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Uppsala University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Jonathan Cedernaes, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

Uppsala University, Sweden

Central Contacts

Jonathan Cedernaes, MD, PhD

Role: CONTACT

jonathan.cedernaes@medsci.uu.se

0184710000

Other Identifiers

CircHFJC2017pt2

Identifier Type: -

Identifier Source: org_study_id