Fasting and Caloric Restriction: A Therapeutic Tool for Chronic Fatigue Syndrome and Fibromyalgia
My Personal Journey With Fasting and Chronic Illness
During a period of intense grief and emotional stress, I noticed an unexpected improvement in my chronic fatigue syndrome (ME/CFS) symptoms when I stopped eating regularly. The loss of appetite, common with emotional distress, led to an unintentional reduction in calorie intake. Despite neglecting self-care and increasing my activity level, I felt physically better than ever—a surprising outcome that sparked my interest in fasting as a therapeutic tool. I first proposed this dietary approach for those with ME/CFS in a prior post. You can read that here.
What Are Fasting and Caloric Restriction (CR)?
Fasting refers to abstaining from food for specific periods, while caloric restriction (CR) involves reducing total calorie intake without necessarily skipping meals. Both methods fall under the umbrella of dietary restriction (DR) and share many overlapping benefits, including neuroprotection and anti-inflammatory effects.
Fasting vs. CR: Fasting may not always reduce total calorie intake (e.g., intermittent fasting protocols with normal caloric consumption), but studies indicate that the positive effects of these practices often stem from reduced calorie intake.
Key Insight: The benefits of fasting and CR, such as reduced inflammation and improved mitochondrial function, are linked to lower overall calorie consumption.
It is possible to fast for 18 hours and then overconsume foods for 6 hours to reach the recommended 2,000 calories per day. This may be indicated for some who struggle to maintain weight or those who are physically active, but keep in mind that the positive effects of CR or fasting seen in the literature are dependent on consuming fewer calories.
Why Consider Fasting for Fibromyalgia and Chronic Fatigue?
1. Caloric Restriction Is Neuroprotective
Protects neurons in the hippocampus and cortex.
Reduces age-related functional decline.
Associated with long lifespans and lower disease rates in populations practicing CR (e.g., Okinawa).
2. Caloric Restriction Reduces Neuroinflammation
Inhibits pro-inflammatory actions of astrocytes and microglia.
Improves brain health by reducing inflammation, which is central to conditions like ME/CFS and fibromyalgia.
3. Fasting Reduces Inflammatory Cytokines
Animal studies show reduced NFkB and increased BDNF with CR or intermittent fasting (IF).
In humans, CR and IF improve markers like insulin, blood lipids, and C-reactive protein (CRP).
4. Fasting Supports Mitochondrial Health
Enhances gene activity (e.g., PGC1-alpha) to produce new mitochondria and combat oxidative stress.
Boosts antioxidant defenses (via SIRT3), preserving neural tissue and promoting stem cell activity.
Different Fasting Protocols to Consider
Intermittent Fasting (IF) Methods
Circadian Rhythm Fasting: Eating only during daylight hours.
Works best with a structured sleep-wake cycle.
16:8 Method: 16 hours of fasting with an 8-hour eating window.
Ideal for beginners and those who prefer mild calorie restriction.
18:6 Method: 18 hours of fasting with a 6-hour eating window.
Increases blood ketone production.
20:4 Method (Warrior Diet): 20 hours of fasting with a 4-hour eating window.
Suitable for more advanced fasters aiming for maximum ketone production.
Long-Term Fasts
Caution: Fasting for 36 hours or more is not recommended for individuals with ME/CFS or fibromyalgia due to risks of muscle wasting, low blood pressure, and worsened orthostatic intolerance..
Keep Fasting Simple
Many popular fasting methods are rebranded versions of basic protocols:
Warrior Diet: The 20:4 fasting method.
5:2 Diet: Two days per week of reduced calorie intake (500–600 calories) with normal eating on other days.
Fast Mimicking Diet: A packaged meal plan to simulate fasting, useful for those unable to prepare meals themselves.
Pro Tip: Fasting doesn’t have to cost money. Use free tools like the ZeroFast app to track fasting schedules and customize your approach.
Recommendations for ME/CFS and Fibromyalgia Patients
Start Slowly: Begin with a 16:8 protocol and gradually increase to 18:6 or 20:4 if tolerated.
Ensure Caloric Adequacy: Avoid significant weight loss unless medically advised.
Focus on Ketone Production: Opt for protocols that increase β-hydroxybutyrate for added benefits.
Consult Your Doctor: Before starting fasting, especially if you have chronic health conditions.
Clinical Studies Supporting Fasting and CR
Memory Improvement: A 30% calorie reduction over 3 months improved memory and reduced CRP levels in elderly participants.
Inflammation Reduction: In a 2-year CR study, participants experienced weight loss and reduced inflammatory markers (CRP, TNF-α).
Metabolic Benefits: IF protocols like 18:6 improve insulin sensitivity, blood pressure, and oxidative stress without significant weight loss.
Symptom Relief in MS: An IF protocol reduced inflammation and improved gut microbiota in patients with multiple sclerosis, without adverse effects.
Hormonal Effects of Fasting
Thyroid Hormones: Short-term fasting protocols (e.g., 16:8) show minimal impact on thyroid function, though longer fasts (36+ hours) may depress T3 levels.
Reproductive Hormones: Studies indicate no significant changes in luteinizing hormone, testosterone, or follicle-stimulating hormone with CR.
Who Should Avoid Fasting?
Fasting is not recommended for:
Pregnant or lactating women.
Children and adolescents.
Individuals with a history of eating disorders.
Elderly individuals who are underweight or frail.
People on medications requiring food (e.g., antibiotics).
Those with poorly controlled diabetes (Type I or II).
Final Thoughts: Fasting as a Therapeutic Strategy
Fasting and caloric restriction offer promising benefits for managing symptoms of fibromyalgia and chronic fatigue syndrome, from reducing neuroinflammation to improving mitochondrial health. By choosing the right fasting protocol and prioritizing safety, patients can explore this therapeutic approach to enhance their quality of life.
References
Bok E, et al. (2019) Dietary Restriction and Neuroinflammation: A Potential Mechanistic Link. Int J Mol Sci. 20(3). pii: E464.
Pani G. (2015) Neuroprotective effects of dietary restriction: Evidence and mechanisms. Semin Cell Dev Biol. 40:106-14.
Witte AV, et al. (2009) Caloric restriction improves memory in elderly humans. Proc Natl Acad Sci U S A. 106(4): 1255–1260.
Meydani SN, et al. (2016) Long-term moderate calorie restriction inhibits inflammation without impairing cell-mediated immunity: a randomized controlled trial in non-obese humans. Aging (Albany NY). 8(7): 1416–1426.
Martin CK, et al. (2016) Effect of Calorie Restriction on Mood, Quality of Life, Sleep, and Sexual Function in Healthy Nonobese Adults: The CALERIE 2 Randomized Clinical Trial. JAMA Intern Med. 176(6):743-52.
Sutton EF, et al. (2018) Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Clinical and Translational Report. 27(6): P1212-1221.E3.
Azizi, F. (2015) Islamic Fasting and Thyroid Hormones. Int J Endocrinol Metab. 13(2): e29248.
Cignarella F, et al. (2018) Intermittent Fasting Confers Protection in CNS Autoimmunity by Altering the Gut Microbiota. Cell Metab. 27(6):1222-1235.e6.
Stekovic S. et al (2019) Alternate Day Fasting Improves Physiological and Molecular Markers of Aging in Healthy, Non-obese Humans. Cell Metab. pii: S1550-4131(19)30429-2.
