Dietary Impact on Sleep, Rhythms and Related Physiology

Uppsala University

Status: Begins enrollment this month

Conditions: Diet Interventions; Circadian Rhythm; Sleep

Treatments: Other: Low-fat dietary intervention; Other: High-fat dietary intervention

Study type: Interventional

Funder types: Other

Identifiers

NCT07138313

CircHFJC2017pt2

Details and patient eligibility

About

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.

Full 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.

Enrollment: 24 estimated patients

Sex: All

Ages: 18 to 32 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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24 participants in 2 patient groups

Healthy diet

Experimental group

Description:

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

Treatment:

Other: Low-fat dietary intervention

Unhealthier diet

Experimental group

Description:

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

Treatment:

Other: High-fat dietary intervention