Diet changes to reduce sleepiness in narcolepsy and idiopathic hypersomnia

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

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.

Why it matters

Who can join: the full rules

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 it's running

• 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
• Email: elizabeth.machan@sydney.edu.au
• Phone: +61408 290 687

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Long-term test of TAK-360 in people with narcolepsy or idiopathic hypersomnia

  This study tests TAK-360 over an extended period to see if it is tolerable for people with narcolepsy type 1, narcolepsy type 2, or idiopathic hypersomnia who completed an earlier TAK-360 trial.

  Recruiting at 33 sites Phase 2/3 Takeda · Chula Vista, California and 32 other locations · NCT07646678

• Expanded-dosing Xywav vs placebo in narcolepsy and IH

  This study tests whether expanded nightly dosing of Xywav helps adults with narcolepsy or idiopathic hypersomnia, compared with placebo.

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• Phase 3 HBS-301 for idiopathic hypersomnia

  This trial will test whether the oral medicine HBS-301 helps adults with idiopathic hypersomnia reduce daytime sleepiness, sleep inertia, and fatigue.

  Recruiting at 42 sites Phase 3 Harmony Biosciences Management, Inc. · Birmingham, Alabama and 41 other locations · NCT07500090

• Long-term ORX750 treatment for people with narcolepsy or idiopathic hypersomnia

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  Recruiting at 24 sites Phase 2 Centessa Pharmaceuticals (UK) Limited · Auburn, Alabama and 23 other locations · NCT07096674

• Evaluating TAK-360 for daytime sleepiness in adults with Idiopathic Hypersomnia

  This study is testing a new medication called TAK-360 to see if it can help adults with Idiopathic Hypersomnia feel less sleepy during the day.

  Recruiting at 28 sites Phase 2 Takeda · Redwood City, California and 28 other locations · NCT06812078

• Extended‑release sodium oxybate for children with narcolepsy type 1

  This will test whether an extended‑release form of sodium oxybate is safer, more convenient, and preferred by children with narcolepsy type 1 compared with non‑extended‑release oxybate options.

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.