Trial results for a study investigating intermittent fasting and a no-sugar diet for Long COVID symptoms were posted on ClinicalTrials.gov on 2026-05-14, showing that overall, participants experienced a decrease of 19.6 points in their LC-Score.
Background
Long COVID, also known as Post-Acute Sequelae of SARS-CoV-2 infection (PASC), refers to a wide range of new, returning, or ongoing health problems that people can experience four or more weeks after first being infected with the virus that causes COVID-19. Symptoms can include fatigue, brain fog, shortness of breath, and pain, significantly impacting quality of life. As specific pharmacological treatments for Long COVID remain limited, there is growing interest in exploring lifestyle interventions, including dietary modifications and fasting protocols, to manage and alleviate these persistent symptoms.
Trial design
This completed cross-over study, identified as Phase NA, enrolled 77 participants with Long Covid19 and Long COVID. The trial assessed the effects of a no added sugar diet, a restricted daily eating window (Time-Restricted Eating, TRE), and one or two full day water fasts. The study aimed to determine if these interventions had an effect on self-reported symptoms of Long COVID (PASC).
Key results
The trial reported changes in LC-Score and the number of Long COVID symptoms, both per treatment group and overall:
- For the 'Fasting 4 Weeks' treatment group, the change in LC-Score was a mean of -10.2 (Standard Deviation 13.6 scores on a scale).
- For the 'TRE 4 Weeks' treatment group, the change in LC-Score was a mean of -2.8 (Standard Deviation 11.6 scores on a scale).
- Regarding the change in the number of Long COVID symptoms, the 'Fasting 4 Weeks' group showed a mean decrease of -5.0 (Standard Deviation 5.6 symptoms).
- The 'TRE 4 Weeks' group showed a mean decrease of -1.4 (Standard Deviation 4.8 symptoms).
- Overall, for all participants, the change in LC-Score was a mean of -19.6 (Standard Deviation 16.3 scores on a scale).
- The overall change in the number of Long COVID symptoms for all trial participants was a mean decrease of -8.3 (Standard Deviation 9.24 symptoms).
- One serious adverse event was reported in the 'TRE 6 Weeks' group, and one serious adverse event was reported in the 'Fasting 4 Weeks' group.
What this means
The results suggest that dietary interventions, specifically intermittent fasting and a no-sugar diet, may help reduce symptoms and improve LC-Scores in individuals with Long COVID. Participants experienced notable reductions in both their overall LC-Score and the number of reported symptoms. While both fasting and time-restricted eating showed some benefit, the 'Fasting 4 Weeks' protocol appeared to yield a greater reduction in both LC-Score and symptom count compared to 'TRE 4 Weeks'. The occurrence of two serious adverse events across the intervention groups indicates that while these interventions show promise, they should be implemented with caution and under medical supervision, especially given the complex nature of Long COVID.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for the study NCT06214455, titled "Intermittent Fasting and a No-Sugar Diet for Long COVID Symptoms", were posted on 2026-05-14 on clinicaltrials.gov.