Prolonged Nightly Fasting in Fibromyalgia

The present randomized-controlled pilot trial will test the feasibility, acceptability, and preliminary efficacy of an 8-week prolonged nightly fasting (PNF) intervention protocol in 20 adults with fibromyalgia. Aim 1: Evaluate feasibility and acceptability of the PNF intervention among participants with fibromyalgia. Aim 2: Evaluate preliminary efficacy of PNF on pain severity and sensitivity, mood, sleep and inflammation.

Fibromyalgia is characterized by chronic widespread pain, sleep disturbance, fatigue, negative mood, and cognitive dysfunction. It is estimated about 4 million individuals in the U.S. are affected by fibromyalgia, which results in high disability, lost productivity, and poor quality of life. Various medications have been tested, but findings suggest only small therapeutic effects with high side effects. First line evidence-based psychosocial interventions, such as cognitive behavioral therapy, also yield only small to moderate treatment effects and they require specialized personnel. Thus, there is a dire need to develop a novel approach to manage fibromyalgia symptoms with a high safety profile, are affordable, and are easily implemented by participants without extensive guidance and support from specialized personnel. Prolonged nightly fasting (PNF) which is a type of time-restricted eating with no or minimal caloric intake for periods of time as few as 12 hours has been shown to promote various health benefits. PNF has also been demonstrated to be highly acceptable and adherable for adults with various clinical condition. Although some dietary patterns have been explored for their impact on pain, the effects of PNF on pain-related outcomes (e.g., pain severity, pain sensitivity), mood, sleep, and inflammation among individuals with fibromyalgia have not been examined. The present randomized-controlled pilot trial will test the feasibility, acceptability, and preliminary efficacy of an 8-week PNF intervention protocol in 20 adults with fibromyalgia.

Participants will engage in the PNF (14+ hours a night of fasting and no calorie containing food or beverages) for 8 weeks.

Participants in HEC group will receive weekly 15-minute videos (once weekly) focused on non-diet/non-fasting health educational content for 8 weeks.

Participants will engage in 14+ hours a night of fasting and no calorie containing food or beverages for 8 weeks. Participants will be allotted one "cheat day" per week, during which they will not need to fast (or track their times)- the day may change weekly and will be based on participant preference. Study staff and study participants will engage in a weekly coaching call (via phone; 5-10 minutes). Weekly coaching calls will last through the duration of the 8-week intervention.

Participants in this group will receive weekly 15-minute videos (once weekly) focused on non-diet/non-fasting health educational content for 8 weeks. Participants will be asked to review the video at their convenience, prior to their weekly coaching call (5-10 minutes) with the study staff. Weekly topics will be as follows: Week 1: Sleep hygiene, Week 2: Sun safety, Week 3: Home safety, Week 4: Driving safety, Week 5: Hydration, Week 6: Dental health, Week 7: Working environment, Week 8: Communication.

The number of days prolonged nightly fasting was completed divided by the total number of treatment days

It will be measured by the Global Satisfaction subscale in an adapted version of the Treatment Satisfaction Questionnaire for Medication. The scores are calculated for each of the subscales, which range from 0 to 100, with higher scores indicating higher patient satisfaction with the intervention.

Total score of Fatigue Severity Scale (ranges from 9-63; higher score means greater fatigue severity)

Total score from Revised Fibromyalgia Impact Questionnaire (FIQR) (ranges from 0-100; higher score means greater fibromyalgia symptom severity)

Total score from Montreal Cognitive Assessment (MoCA) (ranges from 0-30; higher score means better cognitive functioning)

Average of 4 items from the Brief Pain Inventory; each rated on a 0 (no pain) to 10 (pain as bad as you can imagine); ratings are made of pain right now, typical pain, worst pain, and least pain during the past week.

Index of thermal temporal summation, mechanical temporal summation, conditioned pain modulation, and aftersensations (this is standardized Z-score)

Average of 7 items from the Brief Pain Inventory; assessing the extent to which participant experienced that pain interfered with their (1) general activity, (2) mood; (3) walking ability; (4) normal walk; (5) relations with other people, (6) sleep, and (7) enjoyment of life

TST is defined as the total number of minutes asleep between the time a participant goes to bed at night and the time a participant gets out of bed in the morning. TST will be derived from ambulatory EEG sleep monitoring.

Inclusion Criteria: age between 18 and 65 female able to speak, write, and read English classified as having fibromyalgia based upon criteria established by the most up-to-date 2016 American College of Rheumatology (ACR) Criteria for Fibromyalgia has a smartphone. Exclusion Criteria: history of eating disorders assessed by MINI Neuropsychiatric Interview self-report of chronic malignant pain (e.g., cancer, HIV) or systemic inflammatory disease (e.g., rheumatoid arthritis, ankylosing spondylitis, lupus) current use of melatonin or an immunosuppressant medication (e.g., steroids) currently pregnant, trying to get pregnant, or breastfeeding plans to relocate within the next 6 months has diabetes mellitus currently trying to lose weight currently routinely fasting more than 12 hours a night works night shifts