Fasting Mimicking Diet and Markers/Risk Factors Side Effects

The Fasting Mimicking Diet: A Complete Guide

The fast-mimicking diet, also known as FMD, has become an increasingly popular way to lose weight, promote longevity, and support overall health. But what exactly is this unique fasting plan? And could it be right for you? This complete guide will teach you everything you need to know about the science behind FMD, how to follow the diet correctly, the potential benefits and risks, and what the current research says about using FMD strategies to improve your health.

What is the Fasting Mimicking Diet?

The fasting mimicking diet (FMD) was developed by longevity and health expert Dr. Valter Longo. It is a very low-calorie, short-term fasting regimen designed to provide the benefits of traditional fasting while still allowing the dieter to receive essential vitamins, minerals, hydration, and calories.

Read More: Healthy Food Diet Plan

Fasting Mimicking Diet
Fasting Mimicking Diet

The FMD approach focuses on stimulating the body’s natural ability to self-repair and regenerate healthy new cells through fasting while lessening the burden of water-only full fasting. It tricks the body into a fasting mode by providing limited nourishment over a short period. The FMD lasts 5 days out of each month, allowing normal healthy eating the rest of the time.

Fasting Mimicking Diet vs Water Fasting

The main difference between a pure water fast and a fast mimicking diet is that FMD allows a minor amount of caloric intake, while water fasting allows zero calories.

On a water fast, only water, black coffee, plain tea, electrolytes, and non-caloric beverages are allowed. No food at all is consumed. This can become dangerous when extended beyond 3 days without medical supervision. It puts extreme stress on the body.

The FMD provides a small amount of plant-based calories and nutrients specifically tailored not to interrupt the body’s fasting processes and benefits. Fasting Mimicking Diet An average day may include around 750 calories, with 11% protein, 42% fat, and 46% carbohydrates. This helps reduce the negative effects of a water-only fast while allowing regenerative cellular processes to occur.

Developed by Expert Dr. Valter Longo

The fast mimicking diet was created by leading longevity researcher Dr. Valter Longo, Ph.D. Dr. Longo is a professor of gerontology and biological science and director of the Longevity Institute at the University of Southern California.

For over 25 years, Dr. Longo has focused his research on understanding the biological mechanisms behind aging and age-related diseases. Fasting Mimicking Diet His research demonstrates how fasting and fasting-mimicking diets can regenerate stem cells and improve immune system function, reduce osteoarthritis inflammation, and destroy precancerous cells. This led him to develop the proprietary FMD diet through his company Prolon (more below).

Dr. Longo’s fasting diet and longevity research has been featured in major media outlets such as National Geographic, Time Magazine, The New York Times, LA Times, and popular health shows like the Dr. Oz Show. His cutting-edge institute continues to produce new fasting diets and make strides in longevity science.

How the Fasting Mimicking Diet Works

The fast mimicking diet is designed to attain the benefits of fasting through calorie restriction – while still providing minimal nourishment to facilitate the fasting state without causing negative stress.

Here’s an overview of how FMD works:

  • Promotes Ketosis: Drastically reducing calories pushes the body into a metabolic state called ketosis, where it starts burning fat stores for fuel. This is the goal of fasting and produces cleansing byproducts like ketones.
  • Reduces Glucose, IGF-1: Fasting rapidly lowers blood sugar and insulin levels, reduces proteins that feed tumor growth like IGF-1, and facilitates beneficial cellular repair processes.
  • Stimulates Autophagy: Low protein and calories stimulate autophagy – essentially cellular “spring cleaning” where the body breaks down and recycles old, damaged cell parts into energy and building blocks for healthy new cells.
  • Activates Stem Cell Regeneration: Fasting releases stem cells from old tissue and stimulates regeneration. This helps organs repair and renew themselves.
  • Reduces Inflammation: The process of fasting and autophagy decreases systemic inflammation and inflammatory disease processes by clearing damaged cells and recycling proteins.

By facilitating these natural fasting mechanisms – while reducing the burden of complete water fasting – the fast mimicking diet allows the practitioner to safely reap longevity and weight loss results.

Prolon Fasting Mimicking Diet Plan

The originally researched and patented fasting mimicking diet for 5 days per month is called the “Prolon” plan, offered through Dr. Longo’s company.

The Prolon fast mimicking diet plan provides nutritionally supported fasts in prepackaged boxes. Each box contains 5 days’ worth of calorie-restricted, organically sourced vegan meals and snacks averaging 34 to 54 percent of normal caloric intake. Fasting Mimicking Diet The box makes fasting simple by taking all the prep work and calorie counting out.

The Prolon FMD box contains plant-based soups, bars, snacks, supplements, teas, and more – including olives and minestrone soup. A typical day may look like this:

  • Breakfast: An olives snack
  • Lunch: Minestrone soup & supplement pack
  • Dinner: Tomato Bisque Soup
  • Snacks: Nut Bar, Lavender Tea, etc

This fasting diet plan contains precise macronutrients and micronutrients targeted to support the fasting process without disrupting it at 750-800 calories per day.

The convenient pre-packed boxes allow you to enter into a fasted state without having to count calories or prep food. However, some basic supplementation and approved snacks may also be consumed if desired outside-the-box meals.

Fast Mimicking Diet Without ProLon

While the full 5-day Prolon box offers convenience and portion control for the fast mimicking diet, the principles can be followed without buying the pre-made kit. Fasting Mimicking Diet You simply need to stick to a very low-calorie, plant-based diet with specific macronutrient ratios.

Here is an overview of fast mimicking diet rules if creating it yourself:

  • Very Low Calorie: 700-800 calories per day
  • High Fat: 42 to 46% fat (avocados, nuts, oils)
  • Low Carb: Avoid sugars & animal proteins. Get carbs from green veggies, limited whole grains
  • Moderate Plant Protein: 10 to 15% protein from nuts, beans, greens
  • Organic Whole Foods: Emphasize fruits, veggies, plants, healthy fats
  • Hydration: Drink lots of water, herbal tea, electrolytes

With a few simple plant-based recipes, creating your own FMD is very doable. Some basic meal ideas may include:

  • Breakfast: Avocado toast with spinach, nut yogurt berry parfait
  • Lunch: Vegetable soup or minestrone, green salad
  • Dinner: Broccoli rice stir fry with tofu
  • Snacks: Mixed nuts, olives, raw veggies, fruit

The fast mimicking diet meal plan PDF linked below from Dr. Longo provides detailed guidelines on calories, macronutrient ratios, and sample meals to follow when doing the diet yourself without the full Prolon box.

What Can You Eat on the Fast Mimicking Diet?

Since the fast mimicking diet tricks the body into a fasting state, eating non-fasting foods can disrupt benefits. The FMD emphasizes natural, organic plant foods over packaged and processed. Here are the basics:

Fast Mimicking Diet
Fast Mimicking Diet

Allowed FMD Foods:

✅ Non-starchy vegetables: Leafy greens, broccoli, tomatoes, zucchini, olives

✅ Nuts & seeds: Almonds, walnuts, sunflower & pumpkin seeds

✅ Healthy oils: Olive oil, avocado oil, flax oil

✅ Fruits: Berries, coconut, avocado

✅ Ancient grains: Quinoa, brown rice

✅ Legumes: Lentils, chickpeas, bean soup

✅ Herbs & spices

✅ Water, coffee, tea, electrolytes

Not Allowed on FMD Diet:

❌ Grains: Wheat, pasta, bread

❌ Meat: Beef, pork, lamb, poultry

❌ Eggs & dairy

❌ Added sugar

❌ Artificial sweeteners

❌ Processed foods

Following the fasting mimicking diet-approved foods list facilitates clean, autophagy-boosting fasts. It focuses on getting micronutrients from whole plant foods rather than macronutrients from calorie-dense proteins and carbs.

Fast Mimicking Diet Benefits

Extensive research by Dr. Longo and others demonstrates that regularly cycling between the fast mimicking diet and normal healthy eating offers powerful wellness and longevity-boosting effects.

Potential fast mimicking diet benefits include:

  • Weight loss & fat reduction: Burns stubborn fat, reduces BMI and body weight.
  • Supports healthy aging & longevity: Optimizes systems that break down from age and obesity.
  • Regenerates stem cells: Stimulates growth of new healthy cells to repair organs.
  • Fights cancer: Animal studies show the FMD starves pre-cancerous cells while boosting immune defenses.
  • Lowers disease risk factors: Reduces insulin, blood sugar, inflammation, LDL cholesterol as well as diabetes and heart disease risk markers.
  • Improves cognition: Enhances neural regeneration in the brain.
  • Increases cellular cleanup & autophagy: Removes waste material from cells.
  • Recycles immune cells: Breaks down old white blood cells and generates new active ones.
  • Improves arthritis: Reduces inflammation markers causing joint pain.
  • Enhances metabolism: Optimizes metabolic hormones like IGF-1, testosterone, and cortisol.
  • Increases stress resistance: Boosts nerve cell cortex which protects cells against stress.

From helping you lose those final 10 lbs to optimizing organ function and preventing disease, the fast mimicking diet offers impressive enhancements for healthy longevity when done regularly each month.

Is the Fast Mimicking Diet Safe?

Safety is a top concern with any fasting diet – especially for those new to fasting. According to its developer Dr. Valter Longo, the fast mimicking diet is safe for any generally healthy adult when applied in the directed frequency and duration.

  • No serious adverse events have been reported.
  • Clinical trials apply medical supervision to maximize safety.
  • Safety is optimized at 3 cycles per year of 5 days fasting, 25 days normal diet.
  • Very low calories minimize lean tissue loss versus water fasts.
  • Supports hydration, electrolytes, and micronutrients
  • This should be avoided in underweight or malnourished people

Of course, consult your doctor before starting any new diet – particularly if on medications or if you have any medical conditions or special nutritional needs. Fasting Mimicking Diet While considered safe for most, a small percentage may experience side effects like fatigue, headaches, or constipation.

Listen to your body, stay hydrated, rest adequately, and stop if you experience negative reactions. Benefits accumulate with multiple monthly cycles. Fasting Mimicking Diet But remember – regular healthy eating habits combined with the occasional fast is ideal for wellness.

Who Should Avoid the Fasting Mimicking Diet?

While evidence shows the fast mimicking diet is safe and beneficial for most healthy adults, it may not be appropriate for everyone. Use caution or avoid FMD if any of the following apply:

  • Under 18 years old
  • Underweight
  • Malnourished
  • Nutrient deficiencies
  • Pregnant or nursing
  • Diagnosed eating disorder
  • On diabetic medication
  • Liver or kidney conditions
  • Cancer patients (check with doctor)

Children and teens require adequate nutrition to grow properly. Severe calorie restriction can trigger negative mental or physical health issues for vulnerable populations. Fasting Mimicking Diet Play it safe and talk to your doctor if you have any concerns.

For cancer patients or others on specific treatment plans, be sure to discuss implementing the fast mimicking diet with your healthcare provider first to ensure safety and adjust medications if needed.

How Often Should You Do the Fasting Mimicking Diet?

Clinical studies and expert recommendations based on years of trials suggest optimizing the fast mimicking diet benefits safely long-term requires a certain protocol:

  • 3-4 Fasting Cycles Per Year
  • 5 Days FMD, 25 Days Normal Diet
  • Start with Quarterly, Work Up to Monthly

This equates to 1 cycle per season. Fasting just 5 days each month may be excessive. Doing FMD repeatedly without breaks can cause negative effects – even if you have weight to lose.

Cycling between brief fasts and periods of regular healthy eating provides balance and facilitates sustainable results. Work with your doctor to determine the right FMD frequency for your health goals while minimizing risk.

Fasting Mimicking Diet Expected Weight Loss

So how much weight can you expect to lose on the fasting mimicking diet? Since FMD is not intended as a weight loss cure-all but rather a longevity-enhancing strategy – weight management effects can vary.

In studies, Dr. Longo cites, subjects losing between 3 to 7 pounds per 5-day cycle is common. However, dramatic short-term weight loss is not the goal. Fasting Mimicking Diet Optimizing organ function, fat loss, and disease prevention over the long run are better guides.

As a general guideline for average fast mimicking diet weight loss expectations:

  • Over 3 cycles per year, 6 to 12 lbs per year
  • A typical cycle is 3 to 7 lbs over 5 days
  • Loss comes from glycogen stores, fat stores & minor muscle
  • Lose continues 72+ hours into a refeeding period

Of course – actual amounts vary based on factors like starting weight, body composition, and adherence to diet rules during fasts and normal eating periods.

Consistently applying the FMD can gradually promote fat loss. However, emphasizing healthy lifestyle habits during non-fasting periods boosts long-term sustainable weight regulation.

Fast Mimicking Diet Meal Plan

If attempting the fasting mimicking diet without the full Prolon kit, having a meal plan in place for your 5-day fasts makes sticking to it much easier.

This fast mimicking diet meal plan PDF from Dr. Longo and Prolon provides recipes and guidelines for creating your own FMD-compatible meals. It includes:

  • Allowed foods list
  • Daily calorie targets
  • Macronutrient ratios
  • Recommended fasting schedule
  • Sample meals & snacks
  • Recipes & shopping lists
  • Supplement Overview
  • FAQs

Having an FMD cheat sheet you can reference takes the guesswork out of prepping plant-based, low-calorie fasting meals from scratch. It simplifies getting into ketosis fast, avoiding hunger, and successfully triggers the benefits of fasting each month.

Fasting Mimicking Diet Before and After

Convinced the science is there – but still skeptical if FMD can really make a tangible difference for real people long term?

“Fasting Mimicking Diet Before and After” testimonials can provide some inspiring examples of the types of results practitioners experience.

For example, this review from a man who lost 50 lbs with Prolon FMD:

“I lost about 8 lbs in my first round of FMD and I was shocked! It was easy after the first day and I learned so much about healthy eating in the process. Over 6 months I lost 50 lbs just doing the diet 4 times a year and making better choices daily. Fasting Mimicking Diet My energy level is through the roof and I no longer have issues with acid reflux or high blood sugar either. I’m a believer in this program!”

Of course, individual experiences vary widely. But many people find by leaning into periodic short fasts combined with healthier eating, sustainable weight loss, and health improvements occur over months and years.

If you commit and stick with the protocol through a few cycles, the probability of positive changes to your long-term well-being is very high according to leading science.

The Takeaway: Who Benefits from Trying the Fasting Mimicking Diet?

The research continues demonstrating promising effects for improved health markers and body composition when strategically fasting and restricting calories periodically.

The fasting mimicking diet unequivocally flips the script on the outdated myth that we need 3 meals plus snacks daily or metabolism and energy will suffer. Fasting Mimicking Diet By giving digestion a rest while nourishing cells with vital micronutrients, the benefits of cellular cleansing renewal accumulate over each fast.

Cycling 5-day fasts quarterly or monthly is certainly not easy. Yet more and more people even with substantial weight to lose find that after experimenting with the fast mimicking diet, their taste buds adapt, cravings fade and excess fat melts away.

With obesity and chronic health conditions quickly becoming top public health crises – proven programs like FMD that offer a non-pharmacological alternative seem poised to enter mainstream nutrition.

Any generally healthy adult can likely safely implement principles of fasting mimicking for longevity and weight loss advantages under doctor supervision. Fasting Mimicking Diet If you have struggled to lose weight sustainably or want to optimize wellness as you age, speak with your physician about whether a calorie-restricted cyclic fasting program could be right for you.

What is the Fast Mimicking Diet (FMD)?

The Fast Mimicking Diet (FMD) isn’t your typical calorie-restrictive regime. Instead, it’s a structured, five-day eating plan designed to mimic the metabolic effects of fasting while still providing essential nutrients. Fasting Mimicking Diet Developed by Dr. Valter Longo at the USC Longevity Institute, the FMD involves consuming specific plant-based, low-calorie, low-protein, and low-carbohydrate meals.

Key Features of the FMD:

  • Duration: Five days, typically repeated every 3-4 months.
  • Calories: Around 500-600 daily, significantly lower than standard needs.
  • Macronutrients: Low protein (~9%), moderate healthy fats (~35%), and low carbohydrates (~40%).
  • Food Sources: Plant-based soups, energy bars, snacks, teas, and supplements.
  • Goal: Trigger cellular repair and regeneration processes associated with fasting.

Potential Benefits of the FMD:

  • Weight Loss: Studies suggest potential for moderate weight loss, mainly from fat reserves.
  • Metabolic Health: May improve insulin sensitivity and blood sugar control.
  • Inflammation Reduction: Early research indicates reduced markers of inflammation.
  • Cellular Renewal: This might promote autophagy, a cellular cleansing process.
  • Longevity: Ongoing research explores potential anti-aging effects.

Fast Mimicking Diet Meal Plan PDF

Pre-packaged FMD meal plans are available, such as ProLon®, which come with detailed instructions and portion-controlled meals. Fasting Mimicking Diet However, creating your own DIY FMD plan is possible with careful research and guidance from a qualified healthcare professional. Remember, no single PDF can cater to individual needs and health conditions.

Fast Mimicking Diet by Dr. Valter Longo

Dr. Valter Longo is a leading researcher on longevity and aging, spearheading the development of the FMD. His research and protocols form the basis of many commercial FMD programs.

Fast Mimicking Diet and Cancer

Preliminary research suggests that the FMD might enhance the effectiveness of certain cancer treatments and improve patient outcomes. Fasting Mimicking Diet However, significant further research is needed before drawing definitive conclusions. Consult your doctor for personalized advice regarding cancer treatment options.

Fast Mimicking Diet Prolon

Prolon® is a commercially available five-day FMD meal kit developed by L-Nutra, based on Dr. Longo’s research. It provides pre-portioned, plant-based meals and supplements formulated to meet the specific guidelines of the FMD.

Fast Mimicking Diet Cheat Sheet
  • Focus on: Plant-based soups, vegetables, nuts, seeds, olives, healthy oils, and unsweetened teas.
  • Limit: Animal products, refined grains, added sugars, processed foods, alcohol.
  • Stay hydrated: Drink plenty of water and unsweetened herbal teas.
  • Listen to your body: Rest, avoid strenuous exercise, and prioritize sleep during the FMD.
Fast Mimicking Diet Calories Per Day

The FMD aims for around 500-600 calories per day, significantly lower than the typical 2,000-2,500 calorie needs for adults. Remember, drastic calorie restriction should be undertaken only under the supervision of a healthcare professional.

Important Considerations
  • Not for everyone: The FMD might not be suitable for pregnant or breastfeeding women, people with certain medical conditions, or those on specific medications.
  • Potential side effects: Fatigue, hunger, headaches, and mild digestive discomfort are possible during the FMD.
  • Consult your doctor: Discuss the FMD with your doctor before starting, especially if you have any underlying health conditions.

Additional Fasting Mimicking Diet Tips

Trying the fasting mimicking diet for the first time can seem daunting. Here are some additional tips to set yourself up for success:

Schedule Appropriately

Choose a 5-day period that works with your schedule. Avoid busy work days or special events. Many start the diet on a Sunday so the most restrictive days fall on weekends.

Expect Some Discomfort

Headaches, fatigue, nausea, and constipation are common temporary side effects of the fast as the body adjusts. Symptoms normally improve after day 3. Stay hydrated with electrolytes.

Supplement As Needed

Consider supplements like electrolytes, magnesium, potassium, or ginger tea to minimize symptoms like headaches, cramps, or nausea.

Plan Light Activities

Take it easy physically during the low-energy first few days. Light walking or gentle yoga is fine, but this is not the time for intense workouts.

Ease In Your First Meal

Break your fast with gentle foods like broth or juice before resuming normal eating to minimize GI upset.

Stay Busy

Distract yourself from work, hobbies, reading, or light housework to take your mind off food or sensations of hunger. Many find fasting gets easier each round.

Weigh In

Tracking progress with a morning weigh-in can serve as your quantified motivation for each cycle. But also track how you feel, immunity, and other biomarkers.

Learn Something New

Read a book on health, listen to a podcast, or educate yourself more on the fasting process so you understand what’s happening in your body. Knowledge eases the mental struggle.

Mastering the mindset shift that brief bouts of hunger or fatigue are productive rather than destructive is central to embracing fasting’s gifts. Fasting Mimicking Diet Be patient with your body as you would a child – for living systems adapt when gently guided vs. constantly forced. Each fasting bout gets easier until hunger barely whispers while health and joy cry out.

Additional Health Benefits

Emerging research continues to reveal new benefits from fasting and fasting-mimicking diets:


Fasting facilitates cellular clean-up processes in the liver, kidneys, brain, and other detoxifying organs that eliminate waste products and toxins. This cleansing effect leaves you feeling refreshed post-fast.

Skin Health

Studies demonstrate improved collagen production, wound healing, UV damage resistance, and psoriasis reduction from regular fasting.Fasting Mimicking Diet Fasters often notice skin clarity and softness improve attractiveness.

Manage Chronic Pain

Early studies report improved pain thresholds and reductions in inflammation that drive pain in arthritis, nerve pain, and fibromyalgia with fasting cycles.


Along with activating cellular repair processes, keeping fasting glucose and IGF-1 low may support longer healthspans as seen in long-lived populations who eat this way regularly.


Some athletes use short fasts to reduce body fat and “tighten up” muscle while restoring insulin sensitivity that drops during hardcore training periods. Fasting Mimicking Diet Fasting and training intelligently together may support performance.

The wide range of fasting benefits – from life extension to fat loss to mental clarity to reduced pain – continue expanding as our understanding of this ancient healing strategy grows.

The Bottom Line

In closing, the science continues indicating that fasting mimicking diets like the classic 5-day-per-month Prolon FMD system developed by longevity expert Dr. Valter Longo are one of the most promising dietary interventions for improving biomarkers of health, supporting sustainable weight loss and enhancing quality of life as part of a healthy lifestyle.

Fasting Mimicking Diet
Fasting Mimicking Diet

Read More: Fast Mimicking Diet

Of course, consult your physician before starting any diet plan. Fasting Mimicking Diet But for healthy adults struggling with excess weight or seeking protective effects against chronic disease, structured and balanced periodic fasting warrants consideration and looks to offer much more benefit than risk for most people.

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