Intermittent Fasting And MS: Your Questions Answered

Intermittent Fasting And MS: Your Questions Answered

There have been quite a few headlines about “Intermittent Fasting” and its purported benefits for folks living with Multiple Sclerosis.

And I have had quite a few questions from fellow MS’ers about this approach to eating and what the benefits actually are. I thought I would summarize and answer the questions here just in case anyone else is wondering. I do love getting questions from readers (!) so if there is something that you have been wanting to know, just shoot me an email and ask! 


Is Intermittent Fasting A Diet?

No, Intermittent fasting is not a “diet”. It does not dictate the consumption or avoidance of specific foods; rather it is an eating pattern where you cycle between periods of eating and periods of fasting. Intermittent Fasting is not a new concept, as it has been around for a long time and been included as a component of a number of weight loss diets regimens—which may specify specific food guidelines but they often vary. 


What Do You Mean By Periods Of Eating And Periods Of Fasting?

There is more than one (in fact there are several) intermittent fasting patterns including.

  • Alternate Day Fasting: which suggests you eat nothing for 24 hours and then eat normally for 24 hours, repeat. In other words, eat (only) every other day.
  • Modified Fasting (5:2): which suggest that you eat minimally(~500-600 calories) for 2 non-consecutive days (say…Monday & Thursday?) during the week and eat normally for the other 5 days.
  • Time-Restricted Feeding: which suggests that you consume all of your daily calories in a shorter window of time (~6 hours). In other words, eat between the hours of noon and 6 pm only (for example). The specifics of this pattern vary but this is the general idea.

Is Intermittent Fasting An Effective Way To Lose Weight?

Many of the clinical trials studying the effectiveness of intermittent fasting have been conducted on mice. While studies with human subjects have indeed shown some benefit in terms of weight loss and or improved insulin sensitivity, there is little evidence to suggest that intermittent fasting is more effective than moderating your calorie intake every day. More research is needed.

Outside the lab, the effectiveness of intermittent fasting on weight loss depends on how sustainable it is. In other words, if you have difficulty moderating your intake at every meal will consuming fewer but larger meals be a more sustainable practice? Will it fit into your work, family and social life? Will eating all of your daily nutrient needs in one or two meals per day have an impact on your digestion? Is there a risk of it interrupting your sleep? Will you get “hangry” headaches? Will it contribute to (or exacerbate) disordered eating? Sustainability matters in the real world. How sustainable is it really? Food for thought…


Are There Risks?

Intermittent fasting dietary patterns do not appear to cause adverse effects in healthy adult subjects. However, people with poorly controlled blood sugar, a history of disordered eating, Gastroesophageal Reflux Disease (GERD) or any other medical condition, and anyone taking medications should discuss intermittent fasting with their doctor before putting it into practice.

Some things to consider:

  • It may be tough to consume adequate nutrition with the Time-Restricted Feeding pattern.
  • Will there be an impact on exercise habits (exercising on a completely empty stomach?) or fatigue levels?
  • If you have a history of disordered eating, this pattern may not be the best idea for you.
  • What effects can it have on digestion and bowel function?
  • Will eating large meals later in the day impact sleep quality?
  • Supplements are recommended while following these patterns. 
  • Do any of your medications or supplements need to be taken with food? Away from food? This eating pattern may interfere with these guidelines.



What Is The MS Connection?

The research study that sparked such an interest recently can be found here.  And now that you have a better idea of what intermittent fasting is (in general) let’s take a closer look at how it was studied in relation to MS. 


Study Summary:

A mouse study led by University of Southern California researchers led to a small randomized human pilot study to assess the safety and feasibility of either 1) a diet that mimics intermittent fasting  or 2) a ketogenic diet on 60 relapsing remitting multiple sclerosis (RRMS) patients .



The Mice Study:

Mice with induced experimental autoimmune encephalomyelitis (EAE) as a model for multiple sclerosis (MS) were put into two groups. One group completed 3 cycles of a very low calorie, low protein diet– a Fasting Mimicking Diet (FMD)— for three weeks (fasting three days out of every seven days). The other group was fed a Ketogenic Diet (KD) for thirty days continuously.  


Both diets decreased disease severity compared to the control group but the Ketogenic Diet had more modest effects and did not reverse EAE progression in mice. The FMD mice group had clinical reductions to disease symptoms including higher blood levels of corticosterone, improvements in cytokines and T-Cells and a regeneration of myelin. Around 20% of the mice in this group showed a “complete recovery”. 


The (small) Human Study:

60 study participants (age 18-67) with relapsing remitting multiple sclerosis (RRMS) were randomly assigned to a control diet for 6 months, the Ketogenic Diet for 6 months or a single cycle of a modified human Fasting Mimicking Diet for 7 days, followed by a Mediterranean Diet for 6 months. The study aimed to assess the impact of the diet interventions on Health Related Quality of Life (HRQOL).

  • The Control Diet (CD) Included: These participants followed their normal and usual diet.
  • Single Cycle of Fasting Mimicking Diet (FMD) Included:
    • Day 1: Roughly 800 calories from fruit, rice or potatoes.
    • Days 2-8: 100 mL (just under 1/2 cup) vegetable broth or juice with 1 TBS of linseed oil ( also known as flax seed oil) three times daily, plus additional calorie-free liquids.
    • The calorie goal was 200-350 calories or 10-18% of normal daily caloric intake.
    • Participants were advised to consume 2-3 liters of unsweetened fluids each day and were encouraged to use enemas if tolerated. After the seven day fasting period solid foods were reintroduced over three days. After the fasting and refeeding period, a normal calorie, plant-based Mediterranean Diet was maintained for 6 months.
  • The Ketogenic Diet (KD) included: Participants were recommended an average daily intake of <50g carbohydrates, >160 grams fat, <100g protein each day. Participants were provided instructions and guidance on this diet. 


How Did the Study Track Their Intake?

Participants of all three groups self recorded their intake with a 115 item dietary record that did allow the recording of other foods/quantities. 


Results of the Human Study:

Both intervention diets were well tolerated and had high compliance rates. Both the FMD and the KD groups reported meaningful improvements on the HRQOL which includes overall quality of life, physical health and mental health.

In the FMD group, there was a significant drop in white blood cell counts (WBC) that returned to normal after they transitioned to the Mediterranean Diet. It is unknown if participants would have experienced the same benefits if they had skipped the fasting phase and gone directly to the Mediterranean Diet. 

MRI and immune function analysis were not conducted on the human participants and it is unknown if cell repair occurred as it did in the mice study.  This study has not clearly identified the mechanism for the improvements reported by the human study participants; additional research is needed. 


Take Away Message

As I said above… I am very happy that researchers are finally looking at the role nutrition plays in multiple sclerosis. But as frustrating as it is, we are still at the beginning and there is still no evidence to suggest that making these changes would be beneficial. Or how or why they would be beneficial.  I would discourage anyone with MS (or any medical condition for that matter) from adopting a severely restrictive (ketogenic) diet or fasting dietary pattern without the supervision of an MD and a RDN. However, as the researchers continue their work….. the Mediterranean Diet is a safe, healthy and sustainable way to feed your body and your brain every day!


Read my thoughts on the Johns Hopkins pilot study investigating the safety and feasibility of Intermittent Fasting in people with MS.


Thanks for asking! Keep your questions coming!


  • Choi IYPiccio LChildress PBollman BGhosh ABrandhorst SSuarez JMichalsen ACross AHMorgan TEWei MPaul FBock MLongo VD. A  Diet Mimicking Fasting Promotes Regeneration and Reduces Autoimmunity and Multiple SclerosisSymptoms. Cell Rep. 2016 Jun 7;15(10):2136-46. doi: 10.1016/j.celrep.2016.05.009. Epub 2016 May 26.
  • Harvie MNHowell TCould Intermittent Energy Restriction and Intermittent Fasting Reduce Rates of Cancer in Obese, Overweight, and Normal-Weight Subjects? A Summary of Evidence. Adv Nutr. 2016 Jul 15;7(4):690-705. doi: 10.3945/an.115.011767. Print 2016 Jul.
  • Lv MZhu XWang HWang FGuan WRoles of caloric restriction, ketogenic diet and intermittent fasting during initiation, progression and metastasis of cancer in animal models: a systematic review and meta-analysis. PLoS One. 2014 Dec 11;9(12):e115147. doi: 10.1371/journal.pone.0115147. eCollection 2014.
  • Mattson MPWan R. Beneficial effects of intermittent fasting and caloric restriction on the cardiovascular and cerebrovascular systems. J Nutr Biochem. 2005 Mar;16(3):129-37.




I am a Registered Dietitian Nutritionist living in Greensboro, North Carolina. I help people overcome nutrition obstacles and help them meet their nutrition and wellness goals.

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Hi, I’m Mona. I have been living with Relapsing Remitting Multiple Sclerosis (RRMS) for over ten years. As a registered dietitian nutritionist (RDN) I help others with MS to navigate the nutrition superhighway and make sustainable progress toward their unique wellness goals.

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