How a Western versus a fiber-rich diet affects sleep and daily body rhythms

Inverkan av Kost pa Dygnsrytmer Och Amnesomsattning

It will test whether eating a Western-style unhealthy diet versus a healthier, fiber-rich diet changes sleep quality and daily heart, glucose, and hormone rhythms in healthy young adults.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 24 (estimated)
• Ages: 18 Years to 32 Years
• Sex: All
• Sponsor: Uppsala University (other)
• Locations: 1 site (Uppsala)
• Trial ID: NCT07138313 on ClinicalTrials.gov

What this trial studies

This is a randomized crossover experiment where each participant follows two different diets (Western-style high-fat versus a healthier, fiber-rich diet) with about a week of at-home monitoring followed by a multi-day stay in the lab under controlled conditions. Sleep will be measured objectively with polysomnography and with wearable devices, while continuous glucose monitoring, heart rate, and blood pressure will capture 24-hour physiological patterns. Repeated biological sampling across the day will measure hormonal, cardiometabolic, neurodegenerative, and gut microbial biomarkers, and cognitive performance, mood, and appetite will also be recorded. Comparing the same people on both diets will help isolate direct diet-driven changes in sleep and related physiology.

Who should consider this trial

Good fit: Healthy non-smoking adults aged 18–32 with BMI 18–27 kg/m2, stable weight, regular sleep (7–9.25 hours nightly), regular exercise, and three daily meals are the intended participants.

Not a fit: People with chronic medical or psychiatric conditions, diagnosed sleep disorders, recent shift work, smokers, those on chronic medications, or those outside the specified age/BMI ranges are unlikely to gain personal health benefits from participation.

Why it matters

Potential benefit: If successful, the results could point to straightforward dietary changes that improve sleep and daily metabolic rhythms and potentially reduce long-term cardiometabolic or neurodegenerative risk.

How similar studies have performed: Observational and some interventional work links diet composition to sleep and metabolism, but detailed randomized crossover trials with continuous 24-hour physiological and multi-compartment biomarker sampling are limited, so this approach is partly novel.

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

Where this trial is running

Uppsala

• Uppsala biomedical center — Uppsala, Sweden (RECRUITING)

Study contacts

• Principal investigator: Jonathan Cedernaes, MD, PhD — Uppsala University, Sweden
• Study coordinator: Jonathan Cedernaes, MD, PhD

Conditions: Sleep, Diet Interventions, Circadian Rhythm