Intermittent fasting has been crucial in my long-lasting CFS recovery. –  Dr. Courtney Craig

The pleasure of eating good tasting food is undeniable, but food can have a dark side for people with Chronic Fatigue Syndrome (ME/CFS) and Fibromyalgia (FM).

Food! Could avoiding it at times help with ME/CFS and FM?

Food! Could avoiding it at times help with ME/CFS and FM?

Digesting food, for one thing, takes work – lots of it.  In energy-depleted disorders like ME/CFS and FM the energy that goes into digestion could conceivably have been used for healing.

If you have blood volume issues, eating can cause your blood to rush to your stomach leaving you depleted elsewhere.  The cramping, bloating and other gut issues common in Fibromyalgia and ME/CFS take their toll as well.

Dr. Cheney once wryly said that if only ME/CFS patients didn’t have to eat they would get a lot better.  Eating small meals is definitely the way to go for many people with these disorders, but what about occasionally cutting out meals altogether? Would that help?

Dr. Craig on Fasting

Dr. Courtney Craig, D.C., a former Chronic Fatigue Syndrome patient, asserted in a recent blog “Cellular Spring Cleaning: Intermittent Fasting for CFS”  that it can. In fact she found that intermittent fasting helped her avoid relapses and stated it has been ‘crucial’ in her long term recovery.

That got my attention. I’ve tried fasting before. It definitely helped before it wiped me out, but Dr. Craig’s fasts are nothing like the fasts I tried.  Her quickie ‘made for ME/CFS and FM’ type fasts last 8-12 hours and start after an early dinner and end with a late breakfast around noon. Fasting while you sleep is an idea I can get my head around.

Instead of doing them for days, you do short fasts once or twice a week.  I’m definitely going to give them a try. Fasting fits my favorite criteria for treatments: it’s cheap – in fact, you save money doing it – and you can do it from home.

Dr. Craig warns that people with uncontrolled hypoglycemia, adrenal fatigue, or thyroid problems could have problems with intermittent fasting. 

Find out more about Dr. Craig’s ME/CFS and FM fasting protocol including what kinds of ‘foods’ to eat to get you through the fast in her blog “Cellular Spring Cleaning: Intermittent Fasting For CFS“.

I was eager to learn more.

Dr. Courtney Craig (DC) on Intermittent Fasting in Chronic Fatigue Syndrome and Fibromyalgia

 Simply by avoiding meals for 12-18 hours periodically I have been able to stave off relapse and even “bad days.” –  Dr. Courtney Craig

The Nitty Gritty – Doing the Fast

When do you know if should break a fast? I have heard of fasters having to go through a kind of  rough period before their body adjusts, but are there any signs that signal it’s time to cut short a fast even if you haven’t gotten to the 8-12 hour mark? What if you’re feeling great at noon the next day? Your energy is up and your desire for food is gone – what about continuing further?

I can’t stress this enough: I don’t recommend intermittent fasting until the individual has switched over to a low carbohydrate, nutrient-dense diet for at least 3 months or longer. It is vital to first stabilize blood sugar (insulin) and leptin levels. Otherwise, fasts for 8-18+ hours will feel like starvation and can seriously tax already fatigued adrenal glands and disrupt normal thyroid function.

glasses of water

It’s important to keep well-hydrated when you’re fasting

It is also vital to continue to drink water while fasting. Those with POTS or hypotension may also need to replenish electrolytes.

Fasting is very much an individual experience where some will be able to go for longer periods than others. If you can’t fast for 24 hours, 14-16 hours may still have a beneficial effect. It’s important to just be aware of how you feel while fasting, take in adequate liquids, and not exceed your limits. Monitoring blood pressure may also be a good idea during fasts. I encourage working closely with a nutritionist or clinician who is familiar with intermittent fasting.

When should you break the fast? A good rule of thumb in my opinion is to only eat when you’re hungry. Hunger hormones like leptin and ghrelin tightly regulate appetite. However, in individuals who eat a high carbohydrate diet (standard American diet) leptin resistance can occur. Blood sugar quickly drops with leptin resistance resulting in hypoglycemia and severe hunger pangs.

What about that last dinner? Should it consist of extra protein? Do you have any recommendations?

An early dinner that is low in carbohydrates (primarily coming from vegetables) with moderate protein and high in healthy fat is my usual dinner. Loading up on carbohydrates before a fast may seem like the logical thing to do since carbs are stored as glycogen (similar to how athletes carb-load before a race), but this defeats the purpose of the entire fast. In order to get the cellular benefits of fasting, one must deplete glycogen stores and burn fat as fuel through a process known as ketosis.

Insulin needs to be kept very, very low to promote the creation of ATP from fats and not glucose.


Sometimes it does go better with butter …

Ketosis can be measured easily using urine test strips to look for ketone bodies. One ketone in particular, β-hydroxybutyrate, is beneficial to mitochondria. It acts as an antioxidant and increases gene expression of oxidative stress resistance factors (5).

This important discovery potentially creates a “biohack” for intermittent fasting—a simple trick I use if I get hungry during a fast. In theory, as long as you can remain in ketosis (fat burning mode), consumption during a fast will not undo the beneficial effects. This can be achieved by eating small amounts of quality fat (I like coconut butter or butter coffee/tea) which will have little effect on insulin levels, maintain ketosis, and tide you over for another few hours before breaking the fast.

You stated that fasting has helped you avoid relapses. Are there times when you were not doing well that you thought, “This is time to give my body a break and do a short fast”?


Fasting has helped Dr. Craig to limit the duration of her flares

Even in getting my CFS under control after 15 years, I am not immune to the occasional flare-up when I get lazy about diet/supplements or have a lot of stress in my life. Every so often if I feel my symptoms returning or a cold coming on I will focus on trying to do a 14-16 hour fast to boost my immune system. With that (and the combination of diet/supplements) my flares are usually only 1-2 days in duration.

However, in general I try to fast at least once or twice per week for maintenance. I have noticed that I’m much more resilient to stress, poor sleep, and have far less post-exertional malaise. I’m now able to go for long walks (4-5 miles), do basic strength training, lecture for 7 hours, and bustle around NYC without the usual soul-crushing fatigue.

My sister can go on week-long lemon juice fasts and end them up feeling great!  When I’ve fasted in the past I’ve always experienced times when the world just seems brighter. My mental clarity is increased, my body feels better, but even if I’m drinking protein shakes I can’t fast for more than a day and half without feeling like I’m going to fall apart. Why can she whip off a week while I’m struggling after a day?

I can’t fast for 24 hours either—at least I’ve never buckled down and tried it. In theory, I believe the effect can be the same with more frequent, shorter duration fasts. I could only guess why it’s easy for her and not you … maybe her diet is lower in carbohydrates? Higher in good fats? Could be related to hunger hormones as well?

The Science

How did you get into fasting?  I’ve tried it intermittently, but I don’t know if I’ve ever heard it discussed with regard to ME/CFS or FM. It, however, became an important of your treatment plan.  How did you find out about it?

Caloric restriction (fasting) has long been understood to reduce oxidative stress and slow mechanisms of aging in various organisms, but only recently have the biological reasons for this begun to be understood. The effects of fasting are believed to be controlled by the sirtuin family of proteins. The seven known mammalian sirtuin proteins control a variety of functions including aging, programmed cell death (apoptosis), transcription, cellular energy efficiency, mitochondrial biogenesis, antioxidant mechanisms, and circadian rhythm.

I had the opportunity last spring to attend the International Conference on Human Nutrition and Functional Medicine where the theme was mitochondrial health. In attendance was Matt Hirschey, PhD, who has authored several landmark papers that demonstrate that the cellular benefits of fasting are due to the effects it has on sirtuin proteins, specifically SIRT1 and SIRT3 (1); (fig. 2).

free radicals

Fasting promotes the supply of antioxidants that protect against free radicals

SIRT1 stimulates receptors that up-regulate antioxidant molecules (glutathione), increase mitochondrial mass, and inhibit NF-kB—a very important transcription factor that promotes inflammatory cytokines and is implicated in CFS pathogenesis (2). SIRT3 is located within the mitochondria where it also stimulates antioxidant molecules to reduce oxidative stress.

However, new research has also shown that fasting dramatically affects the immune system as well. Scientists at the University of Southern California (USC) found that 2 to 4 day fasts significantly reduced white blood cell counts in humans as well as mice. In the mice group that fasted for 72 hours, stem-cell based regeneration of immune cells occurred. The USC group concluded that fasting may be a viable option to lower the toxicity of chemotherapy in cancer patients by bolstering the immune system with healthy cells (3). I’m intrigued that fasting may have a similar effect to the drug Rituximab which acts by eliminating dysfunctional B lymphocytes and indirectly stimulates the production of new lymphocytic stem cells from bone marrow.

The nutrition naysayers shudder at the idea of voluntary caloric restriction. We are taught that caloric restriction can disrupt hormone balance, stress the adrenals, weaken the immune system, and even result in excessive oxidative stress.

But I was then introduced to the notion of hormesis, a pharmacological concept that indicates that, where a dose-dependent curve is present, low doses of an agent can have the opposite effect of high doses of an agent.  This led me to have a broader understanding of caloric restriction at a practical level.

In the mitochondria this theory is termed mitohormesis, where small amounts of oxidative stress are protective and lead to resilience to further oxidative stress. Hirschey and others predict this resilience is produced when SIRT proteins are stimulated during fasting (2). Fasting thus appears to build a cellular resiliency which is lost when the hormetic threshold is exceeded. Since ME/CFS is defined by chronic oxidative stress, building cellular resiliency could potentially help undo that vicious cycle to improve energy production.

Your blog suggested that during fasting your body gets rid of damaged mitochondria and that clears the way for new mitochondria to be produced. Is that correct?


Removing damaged mitochondria provides room for new healthier mitochondria to show up

Fasting leads to mitochondrial autophagy (self-eating), also known as mitophagy, where genes are stimulated in the mitochondria to undergo apoptosis and destruction by intracellular enzymes. Death and destruction of the cell’s energy factories may seem like a bad idea at first, but when those factories are already damaged by chronic oxidative stress, a bit of remodeling is extremely beneficial.

From my understanding it is not completely understood how mitophagy is controlled, but studies have shown that insulin suppresses mitophagy while glucagon stimulates it. So during fasting, insulin is kept very low and glucagon is elevated which leads to mitochondrial recovery. (4)



Dr. Courtney Craig used traditional and integrative therapies to recover from ME/CFS

Dr. Courtney Craig was first diagnosed with CFS as a teen in 1998, and recovered in 2010 utilizing both conventional and integrative medicine. Trained as a doctor of chiropractic and nutritionist, she now provides nutrition consulting and blogs about what she’s learned on her website.

Check out her Health Rising  blogs here.


1  Merksamer PI, Liu Y, He W, Hirschey MD, Chen D, Verdin E. The sirtuins, oxidative stress and aging: an emerging link. Aging (Albany NY). 2013 Mar;5(3):144-50. http://www.ncbi.nlm.nih.gov/pubmed/23474711

2  Morris G, Maes M. Increased nuclear factor-κB and loss of p53 are key mechanisms in Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS). Med Hypotheses. 2012 Nov;79(5):607-13. Epub 2012 Aug 27. http://www.ncbi.nlm.nih.gov/pubmed/22951418

3  Cheng CW, et al Prolonged Fasting Reduces IGF-1/PKA to Promote Hematopoietic-Stem-Cell-Based Regeneration and Reverse Immunosuppression. Cell Stem Cell. 2014 Jun 5;14(6):810-23. http://www.ncbi.nlm.nih.gov/pubmed/24905167

4  Cuervo, A. M., Bergamini, E., Brunk, U. T., Dröge, W., French, M., & Terman, A. (2005). Review: Autophagy and Aging. Autophagy. 1(3), 131-140. http://www.landesbioscience.com/journals/autophagy/cuervoAUTO1-3.pdf

5  Shimazu T, et al. Suppression of oxidative stress by β-hydroxybutyrate, an endogenous histone deacetylase inhibitor. Science. 2013 Jan 11;339(6116):211-4. Epub 2012 Dec 6. http://www.ncbi.nlm.nih.gov/pubmed/23223453


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