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Because multiple sclerosis (MS) is a chronic condition that can be unpredictable, focusing on beneficial health habits is key for reducing issues like fatigue and pain.

What you eat can be a major part of those lifestyle choices. One eating plan that’s gotten attention for its potential role in reducing flare-ups is the fasting mimicking diet.

Here’s a look at what it entails, possible benefits for MS, and what you need to know if you’re thinking of giving it a try.

The diet is a 5-day, plant-based, very low calorie meal program developed by ProLon, a company founded by Valter Longo, PhD, who’s also the director of the Longevity Institute at the University of Southern California, Los Angeles.

The 5-day program is designed to deliver 34 to 54 percent of normal caloric intake and is meant to be repeated over time.

For example, the Prolon website recommends that people with obesity or overweight do one 5-day cycle per month for 3 consecutive months, and people who are at a healthy weight who exercise regularly complete 1–2 cycles per year.

The diet is called fasting mimicking because unlike a true fast, where you go without any food for a specified period, it calls for eating 1,090 calories on day 1 and about 725 calories on days 2 through 5, with a focus on low carb, high fat foods.

“This means your body will be in a fasted state but not malnourished,” says Sofia Norton, RD, a dietitian who specializes in low carb eating, including the ketogenic diet.

Food options include choices like nut bars, kale crackers, and olives.

When someone has MS, the myelin responsible for conducting nerve impulses throughout the nervous system becomes damaged by immune cells, also called T cells, says Laura O’Connor, RDN, registered dietitian at Huntington Hospital in New York.

The fasting mimicking diet aims to reduce the number of proinflammatory T cells, leading to regeneration of myelin.

This is important because myelin acts as a sheath around nerves, including those in the brain and spinal cord.

Myelin is a primary target in MS, and when it’s damaged, that’s what leads to neurologic issues, as well as pain and other symptoms.

When you’re taking in very few calories, as you would with the fasting mimicking diet, this creates stress in the body and the release of the stress hormone cortisol. This, in turn, may lead to destruction of those immune cells, says Bansari Acharya, RDN, a dietitian specializing in chronic conditions.

“This process may sound detrimental, but it actually encourages the production of new, healthy cells,” she says. “This may be particularly promising for people with MS, as it is an autoimmune disease that’s progressive, so the creation of new cells could be a great benefit.”

Research conducted by Dr. Longo and his team in 60 people with MS found that a 7-day fasting mimicking cycle, followed by 6 months of a Mediterranean diet, led to improvements in quality of life, including physical and mental health.

The fasting mimicking diet also led to an over 20 percent reduction in the total T cell count in 72 percent of the patients, which may have led to symptom reduction.

Although this research is promising, it was done with a small number of participants, says Colleen Chiariello, RDN, chief clinical dietitian at Syosset Hospital in New York.

Some effects may also have been prompted by use of the Mediterranean diet — which is high in fruits, vegetables, good fats, lean proteins, and whole grains — rather than the fasting mimicking diet on its own, she explains.

That means the main drawback to the diet is the limited research on its efficacy, adds O’Connor.

More investigation is needed before real conclusions about its short- and long-term effects on MS symptoms can be known.

Since the plan involves a specific number of calories for 5 days, does that mean you can just give it a try at home on your own, as long as you track consumption?

Not a good idea.

Dr. Longo said this in a news release about the diet: “What we don’t want is patients trying to do this at home without involvement of their specialist or without understanding that larger trials are necessary to confirm that the diet, as a treatment, is effective against multiple sclerosis or other autoimmunities.”

Changing up your eating plan so dramatically, even for just 5 days, needs to be done with the advice of a healthcare provider familiar with your MS medications and symptoms.

It’s also imperative that an expert helps guide you on what to eat to avoid malnutrition and how to transition toward a Mediterranean eating style or another nutrition eating pattern afterward.


Elizabeth Millard lives in Minnesota with her partner, Karla, and their menagerie of farm animals. Her work has appeared in a variety of publications, including SELF, Everyday Health, HealthCentral, Runner’s World, Prevention, Livestrong, Medscape, and many others. You can find her and way too many cat photos on her Instagram.