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The Fasting Mimicking Diet – The Art of Faux-Fasting

The Fasting Mimicking Diet – The Art of Faux-Fasting

Have you tried fasting but don’t respond well to the nutritional abstinence, loathe it, or simply can’t see it through? The fasting-mimicking diet is an alternative approach that mimics the effects of fasting while still allowing some food intake and nutritional supply. This short-term, low-calorie, and plant-based diet has been shown to have deeply beneficial effects on our overall health and longevity. In this article, CARE sheds light on the science surrounding this diet to lose weight and, more importantly, optimize your health.

Blog Author Elena Health Coach at CARE
Elena Iagovitina

Health Coach

Published in Nutrition
10 min read · Feb 05, 2024

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Table of content

What Is the Fasting-Mimicking Diet?

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A fasting-mimicking diet (FMD) is a low-calorie and plant-based diet that mimics the physiological and metabolic effects of fasting, including the activation of cellular stress response pathways and autophagy. FMD involves consuming a low-calorie, low-protein, and low-carbohydrate diet for 4–7 days. [1]

This innovative approach hinges on tricking your body into a fasting state despite the intake of some food and nutrients, thereby initiating cellular and metabolic changes like those achieved through actual fasting.

Even though there are different types of fasting-mimicking diets, a limited calorie intake to prevent nutrient deficiency is the basic concept of this diet’s approach. But how many calories are enough to prevent nutrient deficiency? An exemplary study provided FMD participants between 3000 and 4600 kJ per day, as well as high micronutrient nourishment to prevent the effects of nutrient deficiency, which gives you a good indication. [2]

Typically, on the first day of the diet, you consume around 40% of your normal daily calorie intake (11% protein, 46% fat, and 43% carbohydrate). On the remaining days of the diet, you should consume only 20-30% of your usual calorie intake (9% protein, 44% fat, and 47% carbohydrate). [1] [2]

The Key to FMD is its low protein, low carbohydrate, and high-fat composition, which is calibrated to minimize the insulin and glucose response in your body.

This diet not only aims to promote weight loss but also contributes to improved metabolic health, disease prevention, and longevity, as proven by various scientific studies. [1] [2] [3]

But how does the fasting-mimicking diet work, and how is it superior to actual fasting?

How Does a Fasting-Mimicking Diet Work?

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When you embark on this diet, your body, due to the specific nutrient composition and caloric restriction, perceives a state of fasting. But what does that mean? When and how does our body go into a state of fasting?

When your body perceives a state of fasting, it essentially recognizes a significant reduction in energy intake or a change in the type of nutrients being consumed. Biologically, this triggers a shift from using glucose as the primary energy source to mobilizing stored fats for energy, a process known as ketogenesis. During this ketogenic state, there's a decrease in insulin levels and an increase in glucagon levels, signaling your body to start breaking down fat reserves. [1] [2]

So, in a nutshell, the perception of fasting triggers a shift from glucose-based to ketone-based energy, promoting the metabolic state of ketosis. In this state, your body starts efficiently burning fat for energy, leading to weight loss. [1]

But the fasting-mimicking diet and its effects are about much more than weight loss. Additionally, the stress of this perceived fasting state activates cellular pathways like autophagy. Autophagy is a cellular process where cells cleanse themselves of damaged and old cell components, enhancing cellular repair and renewal. This process is associated with longevity and disease prevention, making this diet not just a weight loss tool but also a contributor to your overall health. [3]

So, now, let’s take a look at the numerous health benefits of a fasting-mimicking diet plan.

What Are the Potential Health Benefits of the Fasting Mimicking Diet?

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Weight Loss and Body Fat Reduction

The FMD facilitates weight loss primarily through ketosis, where your body burns fat for energy instead of carbohydrates. This leads to a reduction in body fat while preserving lean muscle mass. The caloric restriction and change in nutrient composition help in maintaining a calorie deficit, further contributing to weight loss. [1] [2]

Enhanced Metabolic Health

By reducing the intake of sugars and proteins, FMD lowers blood glucose and insulin levels, which can improve your insulin sensitivity. This is particularly beneficial in reducing the risk of type 2 diabetes. Additionally, the diet has been shown to lower “bad cholesterol” (LDL) and triglycerides, which are key markers for cardiovascular health and a preventative factor of cardiovascular disease. [4]

Cellular Clean-Up, Anyone?

Autophagy, your body's cellular cleaning process, is significantly promoted and boosted during FMD. This process helps in the removal of damaged cellular components, which is crucial in preventing various diseases, reducing inflammation, and slowing down the aging process. [3] One could say autophagy is your body’s internal anti-aging and cleansing treatment.

Improving Cognitive Function and Brain Health

The FMD has neuroprotective effects, improving cognitive function and mental clarity. The ketones produced during the diet provide an efficient energy source for the brain, and the reduction in inflammation and oxidative stress supports overall brain health, possibly reducing the risk of neurodegenerative diseases. [1]

Cancer Prevention and Chemotherapy Treatment Support

Emerging research suggests that FMD can support cancer treatment. By reducing glucose and insulin-like growth factor 1 (IGF-1), the diet may inhibit the growth of certain cancer cells. Additionally, FMD has been studied for its potential to enhance the effectiveness of chemotherapy and reduce its side effects. [2]

Stem Cell Regeneration

FMD promotes the regeneration of stem cells, particularly after the fasting period. In your body, stem cells serve as a repair system, continually renewing and regenerating tissues, aiding in healing, and maintaining the normal turnover of regenerative organs, such as blood, skin, or intestinal tissue. This regeneration leads to the rejuvenation of your immune system and improvement in overall cellular function and health, contributing to disease prevention and recovery. [3]

Longevity and Lifespan Extension

The caloric restriction and specific nutrient composition of the FMD have been associated with longevity. By activating pathways related to lifespan extension, such as reducing IGF-1 and increasing ketone bodies, the diet can contribute to a longer, healthier life and reduce risks of age-related diseases. [3] [5]

Each of these health benefits highlights the profound impact of the Fasting-Mimicking Diet, backed by scientific research and studies. The diet's comprehensive and holistic approach to health and wellness makes it an intriguing option if you wish to improve your overall health and well-being.

What Foods Can You Eat on a Fasting-Mimicking Diet?

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While on a Fasting-Mimicking Diet or fasting-mimicking program, your food choices are crucial for the effectiveness of the diet. You should strictly focus your nutritional intake on nutrient-dense, plant-based foods that are low in carbohydrates and proteins but high in good fats.

  • During the first day, you should aim for about 40% of your usual daily caloric intake.
  • The following days, Days 2-5 (or 2-7), you should eat approximately 20-30% of your normal daily caloric intake.

You Can Go a Little Nuts (and Seeds)

Nuts and seeds, such as almonds, walnuts, chia seeds, and flaxseeds, are excellent for a Fasting-Mimicking Diet, offering a rich source of healthy fats, protein, and fiber. These attributes help you maintain satiety and provide you with sustained energy within the diet's caloric limits, while their abundance in omega-3 fatty acids, vitamins, and minerals ensures a well-rounded intake of essential nutrients.

Veggies Are Un-Beet-Able

Vegetables, especially non-starchy ones like bell peppers, cucumbers, and broccoli, are ideal for the Fasting-Mimicking Diet as they are low in calories and carbohydrates yet rich in essential nutrients and fiber. This combination supports the diet's objective of reducing calorie and carbohydrate intake while ensuring an adequate supply of vitamins, minerals, and dietary fiber.

Healthy Fats & Oils

Healthy fats, found in foods like olive oil, avocados, and coconut oil, are integral to the Fasting-Mimicking Diet, as they provide essential fatty acids and help in maintaining energy levels without spiking blood sugar. These fats support your body’s metabolic shift towards fat-burning ketosis, which is crucial in this diet.

Anything where the Kids say yuck! – Leafy Greens

Leafy greens, like spinach and kale, are excellent choices for the FMD due to their high nutrient density and low-calorie content. They provide you with essential vitamins and minerals, such as iron, calcium, and vitamins A, C, and K, while contributing minimal carbohydrates and fats, aligning perfectly with the diet's nutrient-rich, low-calorie eating goals.

Avocadabra

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The avocado is technically a fruit, but the green gold deserves a special spot on this list. Avocados are a superb addition to the Fasting-Mimicking Diet due to their high content of monounsaturated fats, which promote heart health and aid in maintaining stable energy levels. Additionally, avocados are rich in fiber, potassium, and essential vitamins, making them a nutrient-dense choice.

Spill the Tea – Herbal Teas

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Herbal teas complement the Fasting-Mimicking Diet, as they are calorie-free, can help manage hunger pangs, and provide a comforting, hydrating option without breaking the fasting state. Additionally, many herbal teas have their own health benefits, such as aiding digestion, reducing inflammation, and providing antioxidants.

Fasting Mimicking Diet – CARE’s Sample Meal Plan

CARE has curated some fasting-mimicking diet meals that may guide you and inspire you to find fasting-mimicking diet food.

Day 1 (40% of normal calorie intake: 800–1000 calories)

Breakfast:

  • Oatmeal with a small banana and a teaspoon of honey.
  • Green tea or black tea.

Lunch:

  • Quinoa salad with mixed greens, cucumber, cherry tomatoes, and a light olive oil dressing.

Dinner:

  • Grilled vegetables (zucchini, bell peppers, and eggplant) with a small portion of avocado.
  • Herbal tea.

Snacks:

  • A handful of almonds.
  • An apple.

Day 2 (20-30% of normal calorie intake: 400–600 calories)

Breakfast:

  • Sugar-free Chia pudding made with almond milk and a sprinkle of cinnamon.

Lunch:

  • Vegetable broth with a side of steamed kale or spinach.

Dinner:

  • A small portion of roasted cauliflower and a few slices of cucumber.

Snacks:

  • A few slices of carrot.
  • Herbal tea.

Day 3 (20-30% of normal calorie intake: 400–600 calories)

Breakfast:

  • A small smoothie with spinach, half a green apple, and flaxseeds.

Lunch:

  • A small salad with lettuce, arugula, and a few cherry tomatoes, with a teaspoon of olive oil and lemon juice.

Dinner:

  • Steamed broccoli with a sprinkle of turmeric.

Snacks:

  • A handful of berries (like blueberries or raspberries).
  • Green tea.

Day 4 (20-30% of normal calorie intake: 400–600 calories)

  • Breakfast:
    • A small portion of mixed nuts (almonds, walnuts).
  • Lunch:
    • A few slices of avocado with lemon juice and a sprinkle of salt.
  • Dinner:
    • Grilled asparagus and a small portion of roasted Brussels sprouts.
  • Snacks:
    • Cucumber slices.
    • Herbal tea.

Here are a few things to keep in mind during your fasting-mimicking diet:

  1. Hydration is key: Drink plenty of water throughout the day.
  2. Adjust your portion sizes according to your specific caloric needs.
  3. Your focus should be on high-fiber, nutrient-dense foods that are low in protein and carbohydrates but rich in healthy fats.
  4. This diet plan is only an example and can be adjusted based on your individual preferences and nutritional requirements or dietary restrictions.

If you are looking for a more convenient way to see this diet through or are a busy bee, you can take a look at the ProLon fasting mimicking diet. This five-day FMD was created by Dr. Valter Longo, a professor of gerontology and biological sciences, and includes gluten-free and plant-based food that is proprietary and prepackaged.

How Long Should You Do a Fasting-Mimicking Diet?

The duration of the Fasting-Mimicking Diet is short-term and time-restricted, usually lasting between 4 and 7 days. [1] Many people like to start with four to five days in the beginning. Why such a brief period?

This timeframe is sufficient to induce the physiological mechanisms of fasting, such as ketosis and cellular rejuvenation, without imposing excessive stress on your body.

Prolonged fasting can lead to nutrient deficiencies and is not necessary to reap the benefits of this diet – in fact, they can then turn into detrimental effects.

What Are the Potential Health Risks of a Fasting Mimicking Diet?

Risk of Nutrient Deficiencies

Engaging in a calorie-restricted diet like the Fasting-Mimicking Diet, especially if done frequently, too long, or without proper guidance, could lead to deficiencies in essential nutrients.

Not Suitable for Everyone

The Fasting-Mimicking Diet is not appropriate for everyone. It can be inappropriate for people with certain health conditions, such as diabetes, those with a history of eating disorders, chronic diseases, pregnant or breastfeeding women, and children.

Potential Side Effects

Some people may experience side effects such as fatigue, dizziness, headaches, or irritability, particularly during the initial stages of the diet. These symptoms are typically a result of your body adjusting to reduced calorie intake and the shift to fat-burning for energy.

CARE Believes in the FMD

Healthy ageing and enabling you to optimize your wellness and fitness are what make us at CARE thrive. Do not take your health for granted, and start to think about tomorrow.

As a member of CARE, you get a comprehensive and in-depth insight into your present health status with our regular health assessments and blood analysis that showcase your potential health gaps and allow you to prevent diseases in time.

Your health is your greatest asset, and we would be delighted to consult and assist you on your personal health journey!

List of References

Blog Author Elena Health Coach at CARE

Elena Iagovitina

Health Coach at CARE Zurich

About the author

Elena is an enthusiastic Health Coach and blog writer at CARE, with a passion for holistic medicine and health. Previously, Elena worked for almost five years as a coach leading retreats, workshops, and seminars. These included mind-body therapy: breath work, meditation, and massage; as well as energy force therapy: reiki, and qi gong; and third expressive therapy: movement, writing and support groups. Elena shares exciting articles on the blog, on the topic of where the alternative and traditional medicine intersect with Western Medicine. Elena is also the driving force behind the CARE community. In her spare time, she enjoys hiking, traveling to remote locations and dancing. You might also see her on the lake of Zurich as a coast guard. Join her on her journey to learn more about health and discover the world of preventive medicine! Visit all articles written by Elena!