5-Day Fasting Mimicking Diet Plan (FMD) | What Foods to Eat


This past January (2018) Professor Valter Longo of USC released a book on the fat loss and anti-aging benefits of calorie restriction titled The Longevity Diet.

In this book, he outlines a specific form of fasting that is quite a bit different than most of the popular Intermittent Fasting diet plans.

His approach is called The Fasting Mimicking Diet (FMD).

It’s a 5-Day diet hack.

It is just meant to be used once every 6 months.

In a second, you will understand why this isn’t a way you would want to eat each and every day.

In his book The Longevity Diet, he outlines a do-it-yourself fasting mimicking diet plan.

do it yourself fasting mimicking diet plan

This is a way to do the diet with foods you can buy at any grocery store.

I’ll include a do-it-yourself fasting mimicking diet meal plan, but first I want to talk about the done-for-you version called ProLon.

The ProLon Fasting Mimicking Diet Plan

The name ProLon is short for “promoting longevity”.

The reason it is called a fasting mimicking diet is that although you are eating food, you are tricking your body into thinking it is fasting.

I’ll get into the full benefits of fasting later (they are impressive).

The ProLon Fasting Mimicking Diet comes with 5 boxes of food. You consume box 1 on day 1, box 2 on day 2, etc.

Here’s the Prolon Diet menu.

prolon fasting mimicking diet menu

The day 1 box of food is 1100 calories and days 2-5 are each about 750 calories.

What’s in the Prolon NR-3 Vitamin Supplement?

I noticed a supplement in the menu above called NR-3.

NR-3 is a multivitamin that you take 2 times per day, preferably at lunch and dinner.

I was curious about what this supplement consists of, so I tracked down the ingredients.

The majority of the ingredients in the capsules are vitamins(11 in total). In addition to that, there are 2 amino acids; methionine & cysteine.

The amount of vitamins in these pills is lower than a typical multivitamin. I’m guessing that maybe the doses need to be kept to a minimum to ensure your body believes it is actually fasting.

How much does ProLon cost?

How much does ProLon cost

The ProLon meal kit costs between $225 – $249 depending upon how many meal kits you buy at one time. If you buy 1-2 boxes, you pay $249 per box. If you order 3 or more boxes, you pay $225 per box. There is also an option to get subscribe to an auto-ship for $225 per box.

If you break it down by day, your cost is about $50 per day.

That is a bit steep, but since this lasts only 5 days and is to be done only once every 6 months it could be a good option.

For those who like the idea but want to do this with food from the grocery store, I’ll outline a do-it-yourself version.

The Do-It-Yourself Version

fasting mimicking diet menu

This is based on the information in The Longevity Diet book, by Valter Longo.

He’s the guy behind ProLon and the Fasting Mimicking Diet.

My guess is the ProLon version is slightly more effective since it uses exact measurements and was formulated by researchers, but this is a way to test out the diet plan.

The DIY Menu (What to Eat)

Day 1

* 1,100 calories
* 500 calories from complex carbohydrates (vegetables such as broccoli, tomatoes, carrots, pumpkin, mushrooms, etc.)
* 500 calories from healthy fats (nuts, olive oil)
* 1 multivitamin and mineral supplement
* 1 omega-3/omega-6 supplement
* Sugarless teas (up to 3 to 4 cups per day)
* 25 grams of plant-based protein, mainly from nuts
* Unlimited water

Days 2-5

* 800 calories
* 400 calories from complex carbohydrates (vegetables such as broccoli, tomatoes, carrots, pumpkin, mushrooms, etc.)
* 400 calories from healthy fats (nuts, olive oil)
* 1 multivitamin and mineral supplement
* 1 omega-3/omega-6 supplement
* Sugarless teas (up to 3 to 4 cups per day)
*25 grams of plant-based protein, mainly from nuts
* Unlimited water

The above components can be divided between breakfast, lunch, and dinner, or they can be taken as two meals and a snack.

Day 6

* Transition diet
* For 24 hours following the end of the five-day FMD, patients should follow a diet based on complex carbohydrates (vegetables, cereals, pasta, rice, bread, fruit, etc.), and minimize the consumption of fish, meat, saturated fats, pastries, cheeses, milk, etc.

Why would we purposely eat so little for 5 days straight?

Here’s why…

What are the Benefits?

fmd diet benefits

I’ve used the protein sparing modified fast (PSMF) before.

This is different.

This isn’t Intermittent Fasting either.

…or time Time Restricted Eating.

This is more aggressive than any of these other fasting methods I have mentioned. With this diet, the goal is slight starvation.

Nonstop food and feeding is a modern thing.

Fasting from time to time is healthy for us.

Dr. Longo claims that it takes 2-3 days for the health benefits of fasting to really kick in.

Here are the health benefits of the fasting mimicking diet plan:

  • Anti-aging
  • Burning of visceral fat
  • Killing damaged cells and replacing with newly regenerated cells from activated stem cells

I am especially interested in the visceral fat part.

I’m close to 50 and the older I get the more fat my body likes to store on my midsection compared to everywhere else.

All of my friends who are the same age are seeing this as well.

Fasting for 5 days is a way to directly target this stubborn belly fat.

fasting mimicking diet to get rid of belly fat

…but not eating anything for 5 days sounds nutty.

Dr. Longo’s studies showed impressive benefits of 5-day fasts.

He even found that fasting for 5 days, was one way to stop the spread of cancer, but the cancer community did NOT want to do this.

He realized that fasting with only water had a 95% failure rate.

People couldn’t do it.

The National Cancer Institute believed that Dr. Longo’s findings were so promising they gave him grants to develop a 5-day diet that could mimic fasting.

(It’s a pretty big deal when the government gives you grants to develop your diet.)

Over a period of time, the 5-Day FMD plan was developed.

The benefit that jumped out at me was this…

The body continues to focus on burning belly fat, long AFTER returning to a normal diet.

“Shifting the body into an abdominal/visceral fat-burning mode, which continues after returning to a normal diet (probably due to epigenetic changes, which are modifications of the DNA and proteins that bind DNA)”

So the Fasting Mimicking Diet Plan is like hitting the “reset button”.

This diet is a way of killing damaged cells and replacing with new healthier cells.

fasting to fight cancer

Your body also switches to target belly fat even after this 5-day period.

Dr. Valter Longo has some controversial viewpoints.

He has stated that the data show that eating over 100 grams of protein per day increase IGF-1 and mTOR signaling which accelerate aging.

He also points out that studies show high levels of protein consumption like this can QUADRUPLE the chances of getting cancer.

low protein diet for longevity

I used to eat a high protein diet.


Cancer runs in my family so my current diet is lower than 100 grams per day in protein.

It took me a loooong time to get used to the idea of eating a lower protein diet.

Studies have shown that you can maintain muscle on a low protein diet as long as you add in resistance training.

What About Ketosis and the FMD Diet?

Dr. Valter Longo believes that fasting is the best way to reach a ketogenic state.

“Fasting is the original way to generate ketogenesis from the inside.”

He also believes in achieving ketosis from a high fat ketogenic diet is harmful to your health.

“If you look at, for example, some of these high-fat high protein diets, in the beginning, everybody thought they were a great idea because people lost weight, and then it turns out, as the epidemiological studies started coming out, they are some of the worst diets you can have, and they promote higher mortality, and higher incidents of all kinds of diseases…and sure enough, there are no very long-lived populations that have a high animal fat, high animal protein diet.”

Although I don’t personally follow a ketogenic diet, I do realize that this is a super popular diet right now.

Here’s a video outlining ketogenic fasting mimicking diet plan.

The gentleman in the video believes that following more of a ketogenic approach to the fasting mimicking diet would make it more effective.

I actually agree with Dr. Longo that the keto diet isn’t healthy over the long-term.

It can work for some people in the short term.

For the long-term, I would advise against it.

The Results from this Diet Plan

First, let’s talk about the results of the Fasting Mimicking Diet study.

It’s titled:

Fasting-mimicking Diet and Markers/risk factors for Aging, Diabetes, Cancer, and Cardiovascular Disease.

  • 100 people were involved in the study
  • 50 subjects ate normally for 3 months
  • 50 subjects did 3 5-day rounds of the fasting mimicking diet

The subjects who followed the fasting mimicking lost an average of 5 pounds and the majority of this weight loss came from abdominal fat.

They also lost 1 inch off of their waist on average.

Here are the results of a woman who used the 5-day ProLon Fast.

  • When she started the fast, she was 165.2 pounds.
  • At the end of the fast, she was 158.8 pounds.
  • So she lost around 7 pounds in 5 days.

Like the subjects in the experiment, it also seems that the majority of her weight came off from the abdominal region.

For people who have stubborn belly fat, this could be something that they should try.

Is this a safe diet?

This is a safe diet for most healthy people. Most humans have the ability to go without food for 21+ days and the Fasting Mimicking Diet plan only lasts for 5 days.

According to the official website, here are the people who should NOT use the ProLon Fasting Mimicking Diet:

  • Under 18
  • Protein-Deficient
  • Have different dietary needs that are mismatched with the Prolon meal diet
  • Sensitive or allergic to soy, nuts, celery, sesame, or oats
  • Pregnant
  • Suffer from any medical condition or sickness
  • Have Body Mass Index (BMI) less than 18

I have to think that this is a safe diet for most people.

Humans evolved under periods of time where very few calories were present, or no food at all was available.

Water is a different story.

Some people actually use dry fasting to lose weight.

I wrote an article about dry fasting for weight loss, although I will probably never use this style of fast.

Do-it-Yourself FMD Review

Since I showed the results of the 5-Day ProLon diet, I also wanted to show real-world DIY fasting mimicking diet review.

Dr. Valter Longo does discourage people from doing their own versions because it is possibly unsafe.

I’m not a doctor and I’m not giving medical advice, but I believe most people would be fine with a do-it-yourself version.

The woman in this video lost 3.5 pounds.


She says she ate a large meal the day before, so she was probably 1 pound heavier than normal.

In reality, she most likely lost closer to 2.5 pounds over the 5 day period.

Here’s where it gets interesting.

She continued to lose weight for 2 days after her do-it-yourself fasting mimicking diet was over.

So she lost close to 5 pounds.

Should you try this dieting approach?

woman eating salad for fat loss

I really like the benefits of occasional fasting, so I’ll probably attempt a do-it-yourself version at some point.

This is just an introduction,

If you want to attempt a do-it-yourself version, pick up his book on Amazon.

If you want to do it in a precise way, check out the ProLon website.

Almost every ProLon review I have seen online has been a positive one.

If I like the results and don’t turn into a zombie for 5 days, I’ll use FMD once every 6 months.

On paper, it makes a lot of sense.


-Rusty Moore

As a former fitness coach to fashion models, I can teach you how to increase muscle definition without adding size.

Click Here to check out my premium courses.