Diet changes to reduce sleepiness in narcolepsy and idiopathic hypersomnia

A Novel Dietary Approach to Manage Symptoms of Narcolepsy and Idiopathic Hypersomnia

This project will try whether a 12-week whole-food ketogenic diet versus an isocaloric standard whole-food diet reduces daytime sleepiness and improves quality of life in adults with narcolepsy or idiopathic hypersomnia.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 30 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: University of Sydney (Academic / other)
• Locations: 1 site (Macquarie Park, New South Wales)
• Trial ID: NCT07006233 on ClinicalTrials.gov

What this trial studies

This is a single-centre, randomized, parallel-group trial comparing a 12-week whole-food ketogenic diet (WFKD) to an isocaloric whole-food diet (WFD) in adults with narcolepsy type 1, type 2, or idiopathic hypersomnia. The primary focus is on feasibility and tolerability using the RE-AIM framework, with secondary outcomes including daytime sleepiness, sleep onset latency, psychomotor vigilance, metabolic health measures, and quality of life. Participants will be stratified by diagnosis and will monitor ketones via finger-prick and urinary dipstick while continuing usual medical care. The design includes mixed methods to capture patient preferences and implementation barriers to broader adoption.

Who should consider this trial

Good fit: Adults (18+) with ICSD-3–confirmed narcolepsy type 1 or 2 or idiopathic hypersomnia, BMI >18.5 kg/m2, who habitually consume >130 g carbohydrate/day, are willing to change their diet and monitor ketones, and have internet access and English proficiency.

Not a fit: People who are underweight (BMI ≤18.5), already follow a low-carbohydrate or ketogenic diet, are unwilling to consume animal protein/fat or to monitor ketones, or cannot attend the single centre or use required remote tools may not receive benefit from this intervention.

Why it matters

Potential benefit: If successful, this approach could offer a practical non-drug option to reduce sleepiness and improve metabolic health and quality of life for people with hypersomnolence.

How similar studies have performed: Ketogenic and low-carbohydrate diets have shown benefits for metabolic health and some neurological conditions like epilepsy, but their effects on narcolepsy and idiopathic hypersomnia are largely untested.

Eligibility criteria

Inclusion Criteria:

* Evidence (from multiple sleep latency test, 24-hour polysomnography, or actigraphy) of diagnosis of narcolepsy type 1, narcolepsy type 2 or idiopathic hypersomnia that meets ICSD-3 criteria.
* For the NT1 subtype, patients must have been screened positive for the HLA DQB10602 genotype.
* Body mass index \>18.5 kg/m2
* 18 years or over
* Be willing to be involved in dietary change that may include animal protein and fat.
* Be willing to monitor ketones via finger-prick and urinary dipstick.
* Habitual diet is a standard diet consuming a moderate or high carbohydrate level (defined for the study as above 130g carbohydrate/day).
* Willingness to provide informed consent and willingness to participate and comply with the study requirements.
* Access to a computer, laptop, tablet, or smartphone and stable internet access.
* Proficient comprehension of English language (able to independently read information sheet) and availability of a support person during consultations if English comprehension is challenged.

Exclusion Criteria:

* Body mass index \<18.5 kg/m2, history of an eating disorder with an EDE-Q score greater than 3.
* Participants who have sustained significant weight loss in the last 3 months (\>5% change in total body weight).
* Previous bariatric surgery or current prescription of weight loss medication.
* Diagnosis of unstable psychiatric disorders (excluding anxiety or depression).
* Cognitive impairment that limits ability to understand the study requirements or provide informed consent.
* Physical impairment that limits ability to meet the study requirements.
* Non-English speaking and inability to read the Participant Information Sheet.
* No access to stable internet and device on which to participate in telehealth consultations and complete study questionnaires.
* Person lactating, pregnant or of childbearing potential who are not willing to avoid becoming pregnant during the study period.
* Habitual diet is currently low carbohydrate/ketogenic (defined for the study as \<130g carbohydrate/day based on screening 24 food hour recall).
* Habitual diet excludes animal products (e.g. Vegan diet).
* Laboratory parameters that may indicate alternate catalyst for hypersomnolence in the opinion of the study physician, including abnormal: full blood count, thyroid function, Epstein-Barr Virus, erythrocyte sedimentation rate, cortisol, antinuclear antibodies, extractable nuclear antigen test, positive rheumatoid factor, Antistreptolysin O positive, Iron studies or multiple biochemistry panel.
* Participants who have changed their medication prescription or dose within the preceding 4 weeks.
* Participants with inherited metabolic disorders, prior history of hypoglycaemia or insulinoma
* Participants with insulin dependent Type 1 or Type 2 diabetics prescribed insulin which may interfere with the participant's ability to meet the study requirements.
* Participants with uncontrolled medical conditions or patients with significant medical co-morbidities who in the opinion of the study physician, would be at risk of adverse health consequences due to the study intervention (e.g. poorly controlled type 2 diabetic patients who are not prescribed insulin)
* Current cancer diagnosis (excluding skin cancers or benign cancers)
* Current active enrolment in a pharmaceutical or intervention based clinical trial or participant who may have received an investigational new drug within the last 12 weeks.

Where this trial is running

Macquarie Park, New South Wales

• Woolcock Institute of Medical Research — Macquarie Park, New South Wales, Australia (Recruiting)

Study contacts

• Principal investigator: Elizabeth A Machan, PhD — University of Sydney
• Study coordinator: Elizabeth A Machan, PhD

Conditions Idiopathic Hypersomnia; Narcolepsy Type 1; Narcolepsy Type 2; keto diet; ketogenic; keto; whole food diet; narcolepsy