NCT06214455Completed
Intermittent Fasting and a No-Sugar Diet for Long COVID Symptoms
The Effect of a No-added Sugar Diet, Time-restricted Eating and Periodic Water Fasting on Long COVID Symptoms
Source: ClinicalTrials.gov · Last updated 14 May 2026
Brief summary (registry, in English)
This cross-over study will assess a no added sugar diet, a restricted daily eating window, and one or two full day water fasts to determine if there is an effect on self-reported symptoms of Long Covid (PASC).
- Status (registry)
- Completed
- Study type
- Interventional
- Enrollment
- 77 (actual)
- First submitted
- 3 Jan 2023
- Start date
- 4 Nov 2022
- Primary completion date
- 1 Jul 2024
- Lead sponsor
- Pacific Northwest University of Health Sciences
- Diseases
- Long COVID and ME/CFS
- NCT number
- NCT06214455
What you commit to
- Study type: Interventional
- Participants enrolled: 77
- From 4 Nov 2022 to the primary completion date, 1 Jul 2024
- 2 sites in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Likely COVID-19 or SARS-CoV-2 infection \< 45 days before enrollment
- Previously fasted more than 18 hours with Long COVID
- Previous Autoimmune condition
- Previous Chronic Health Conditions that did not fully resolve (Includes ME/CFS, Lyme Disease, and Fibromyalgia)
- Prescription anticoagulation medication that cannot be halted during the study period. Brilinta (ticagrelor), Plavix (clopidogrel), Coumadin, Warfarin etc.
- High Cholesterol medications that cannot be halted or reduced during the study period (Fenofibrate, Statins \> 10 mg)
- Anti-inflammatories or immunosuppressants such as Steroids, Low dose Naltrexone (LDN), Maraviroc, Remicade/Infliximab or Colchicine that cannot be halted during the study period
Other illness
- Past history of an eating disorder.
- Severe pulmonary disease requiring supplemental oxygen
- Any recent (90 days) history of malignancies, fractures, surgery, radiation, chemo, anesthesia, or traumas
- Diagnosed with Type I or Type II Diabetes
- Heart condition (Coronary artery disease, Heart valve disease, Heart No failure, Stroke)
- Liver disease
Other
- Body Mass Index (BMI) must be 20 or greater
- Currently doing intermittent fasting
- Pregnant or breast-feeding
- Partial loss of vision due to macular degeneration
- Pre-pandemic Arrythmia
- Metformin, Ivermectin, or peptides such as BCP-157 that cannot be halted during the study period
Who the study is looking for
- Adult (18-69 years old)
- Five or more common Long Covid symptoms
- Free from fever \> 100F and known bacterial and parasitic infections
- Must indicate willingness to limit certain supplements and report all medications.
- Must indicate willingness to make significant dietary changes - and limit daily eating to an 8 or 10 hour window.
- Must indicate willingness to attempt 36 hr or 60 hr water fasts each week for 4 weeks.
- Have a valid email address and phone number
- Reside in the United States
- Be able to read and to communicate in English
- Must indicate willingness to avoid "extra" supplements such as Fish Yes Oil, Cod liver Oil, Krill Oil, MCT oil, Coconut Oil, Tumeric/Curcumin, Berberine, Quercetin (\> 500 mg), Red Yeast Rice, French Marine Bark extract, Red Sage, Ginko biloba, Oregano Oil, Peppermint Oil, Black seed oil, Cinnamon bark extract, Elderberry, Stinging Nettle, Milk Thistle, Monolaurin, Vendicinals 9, Tollovid, QuadraMune and all Probiotics.
- Must indicate willingness to avoid certain nutraceuticals such as Zinc (more than 25 mg), Arginine, Glutamine, Palmitoylethanolamide (PEA), Alpha Lipoic Acid, L Carnitine and Taurine during the study period.
- Must indicate willingness to avoid longevity supplements such as NAD+, Niacin, NMN, Nicotinamide Riboside, Spermidine and Fisetin during the study period.
- Must indicate willingness to halt Olive oil consumption greater than 1 tsp daily during the study period.
Age in the registry: 19 years to 69 years · Sex: All · Does not accept healthy volunteers
Sites (2)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Remote trial - anyone residing in the United States Coordinator of this site? Confirm its status | Boulder | United States | Unknown status |
| Pacific Northwest University Coordinator of this site? Confirm its status | Yakima | United States | Unknown status |
Related publications
- Intermittent fasting and a no-sugar diet for Long COVID symptoms: a randomized crossover trial.Sci Rep · 2025 · PMID 40730806
This page is information, not medical advice. Discuss any trial with your doctor.