Investigating how diet affects our internal body clock

Uncovering the Impact of Diet on the Human Circadian Timing System

This study is testing how high-fat and low-fat diets affect our body's internal clock and how quickly we can adjust to changes in light when eating these diets.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 14 (estimated)
• Ages: 18 Years to 40 Years
• Sex: All
• Sponsor: Oregon Health and Science University (Academic / other)
• Locations: 1 site (Portland, Oregon)
• Trial ID: NCT04743271 on ClinicalTrials.gov

What this trial studies

This study aims to explore the impact of diet, specifically high-fat versus low-fat diets, on the human circadian timing system over a 46-day period. Participants will undergo a randomized cross-over design, spending 28 days as outpatients and 18 days as inpatients during two 9-day visits. The research will assess how quickly individuals can adjust their internal clocks to changes in light schedules when consuming different types of diets. The findings could provide insights into the relationship between dietary composition and circadian rhythms in humans.

Who should consider this trial

Good fit: Ideal candidates are healthy, lean men and women with a BMI between 18.5 and 24.9 kg/m².

Not a fit: Patients with major dietary restrictions, chronic health conditions, or those who have recently traveled across time zones may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to dietary recommendations that optimize circadian health and improve overall well-being.

How similar studies have performed: While there is limited research on humans, rodent studies have shown that high-fat diets can disrupt circadian rhythms, suggesting potential relevance for this investigation.

Eligibility criteria

Inclusion Criteria:

* Healthy, lean men and women

Exclusion Criteria:

* Major dietary restrictions (such as entirely dairy-free and/or meat-free diets)
* A body mass index (BMI) of 18.5\< \[BMI\] \< 24.9 kg/m\^2 and a waist circumference \<94/80cm
* Currently psychiatrically/psychologically unsuitable for participation
* Drug/alcohol use, including smoking
* Medication/drug use, including prescribed and over-the-counter medications
* History of working irregular day and night hours, regular night work, or rotating shift work for the 1 year prior to the study.
* Traveled across more than 1 time zone during the 3 months prior to the study
* Currently consuming a habitual high-fat diet
* Chronobiologic and sleep disorders
* Diseases of the Cardiovascular System
* Metabolic Syndrome; Two or more of these factors will be excluded from the study:

  1. HDL cholesterol of less than 40 mg/dL in men or less than 50 mg/dL in women;
  2. systolic blood pressure\>135 mmHg or diastolic blood pressure\>85 mmHg;
  3. Fasting blood glucose ≥ 100 mg/dL;
  4. Triglycerides ≥ 150 mg/dL.
* Pre-Diabetes/Diabetes
* Hypertension
* Disorders of the Respiratory System
* Disorders of the Kidney and Urinary Tract
* Infectious Diseases
* Disorders of the Gastrointestinal System
* Disorders of the Immune System
* Disorders of the Hematopoietic System
* Neoplastic Diseases
* Endocrine and Metabolic Diseases
* Neurologic Disorders
* Subjects must not be currently participating in another research study that would influence their safe participation in our study

Where this trial is running

Portland, Oregon

• Oregon Health & Science University — Portland, Oregon, United States (Recruiting)

Study contacts

• Principal investigator: Andrew McHill, PhD — Oregon Health and Science University
• Study coordinator: Andrew McHill, PhD

Conditions Diet, High-Fat; Circadian Rhythm; High Fat; Diet