Fasting-mimicking diet: how to reduce weight in 5 days

Losing weight in only five days seems impossible, don’t you think? But not if you follow the fasting-mimicking diet.

This scientific, nutrient-dense diet offers a short but impactful weight loss strategy. Plus, the fasting-mimicking diet also provides a wide range of health benefits, from the heart to cognitive health. 

The concept of a fasting-mimicking diet is simple; you only need to fool your body into thinking it is fasting, but technically, you are not. Intrigued? Who isn’t, right?

Well, the fasting-mimicking diet refers to a reduced-calorie diet with macro- and micronutrient breakdown for your body to perceive it is fasting. 

Featured product offer
ProLon® 5-Day Meal Program
  • The only nutrition program designed and tested by 14 renowned universities worldwide.
  • Clinically shown to reduce fine lines and wrinkles after 3 cycles (15 days total).
  • Each kit contains various soup flavors, snacks, teas, and supplements.

How does the fasting-mimicking diet work?

Following the definition above, the fasting-mimicking diet allows you to eat smaller amounts of food, in contrast to the traditional concept of fasting. Its scientific process involves the so-called autophagy, which refers to somewhat “housecleaning” of the cells in your body. 

Autophagy is like a garbage truck that takes away unwanted byproducts of your cell activity. The cells have significant roles in the body, including keeping us breathing and making energy.

As the body cells work non-stop every minute of the day, they produce waste along the process, and their junk needs to be cleaned up–this is where autophagy steps in. 

How does the fasting-mimicking diet work?

The more clean-up autophagy does, the better for your overall wellness, including the benefit of lesser risk for fatal diseases in the future and longevity. The fasting-mimicking diet allows your body to speed up autophagy, meaning more clean-up [1]. 

5 days of fasting-mimicking diet for weight loss 

Behind the fasting-mimicking diet is Dr. Valter Longo, an Italian-American biogerontologist and cell biologist, and his team at the Longevity Institute at The University of Southern California. According to them, you only need to follow a five-day diet plan to reap its benefits in weight loss [2]. 

In order to make the fasting-mimicking diet effective, you must speed up autophagy to clean out old and damaged cells while preserving muscle mass at the same time. Following the approach below, you only need to do the fasting-mimicking diet for five days. 

DayDietWhat happens?
Day 1 You should only consume 1,100 calories, with 11 percent from protein, 46 percent from fat and 43 percent from carbohydrates.Your body starts to transition into a fasting stage. It upregulates fat burning and prepares to begin autophagy, the cellular clean-up.  
Day 2A lesser amount of calories should be eaten, just 725 calories, with a macronutrient breakdown of 9 percent from protein, 44 percent from fat and 47 percent from carbohydrates.The fat-burning process that’s happening in your body further increases, and the cellular clean-up is improved. 
Day 3 Similar to Day 2.The cellular clean-up continues, and your body begins to reach ketosis, the process by which your body fat is burned to be the primary fuel source of your body. 
Day 4 Similar to Day 2.Still, the cellular cleaning and renewal continue along with fat burning. 
Day 5 Similar to Day 2. The fast is completed, and re-feeding beyond day 5 is only to fuel overall wellness [3].

The five-day fasting-mimicking diet is recommended to be done at least once a month within three months to obtain optimal results. During the five days of the diet, you must drink a minimum of 70 ounces of water every day. 

Plus, you must not consume any caffeinated drinks. Instead of not eating at all, you are technically doing calorie restrictions while the diet itself mimics the traditional fasting method. 

Calorie restriction during fasting-mimicking diet

In the standard fasting diets, the ultimate challenge is focusing on what you eat. If the dieter avoids eating during fasting, they may still consume a lot of foods with low nutritional value during the eating window. 

Eating low nutritional value foods is not sustainable for both short and long term if you aim to lose weight, even if you eat them once in a while. They lack essential nutrients, can’t help in body repair and turn your metabolism out of whack. The whole fasting effort can turn into a waste. 

Unlike with the fasting-mimicking diet, there is a set eating schedule, daily calorie requirement and recommended foods to eat containing all the needed nutrients to repair and maintain itself.

The fasting-mimicking diet provides meals that are low-calorie, high-fat and low-carb, causing it to generate more energy from non-carbohydrate sources once glycogen stores have depleted in the body, which is called gluconeogenesis [4].

The calorie restriction of the fasting-mimicking diet mimics the physiological response of your body to traditional fasting methods, including cell regeneration, decreased inflammation and excessive fat loss. 

Dr. Longo and his team of health experts advise dieters to consult with their medical professionals before following the five-day diet. It is important to know if you can sustain the diet, considering your medications or health conditions, as the fasting-mimicking diet is not a one-time thing; it needs to be done for several months in a row to achieve optimal results. 

Featured product offer
Future Kind+ Plant-Powered Meal Shake
  • Contains 16 g of protein to promote fullness.
  • 100% vegan and gluten-free.
  • Combines organic protein powders, probiotics, fiber mix, super greens and digestive enzymes.

Foods to eat and to avoid

You can consume foods while you are on the fasting-mimicking diet; just make sure to calculate the calories you eat. During the five days, you must take note to eat only plant-based protein, healthy fats and low carbohydrate food sources [5].

Your diet must include a variety of foods that are all plant-based while still can satisfy your taste buds and appetite. 

Nutrition bars, kale crackers and soups are a few of the foods that fasting-mimicking dieters usually eat. Make sure that the foods you eat are a combination of macro- and micronutrients designed to keep the body nourished whilst simultaneously going through the rejuvenating process of the fasting state. 

foods to eat and avoid

Usually, the dieters who do the fasting-mimicking diet avail the pre-packed meal kits that are prepared following the requirements of it.

The meal kits of the fasting-mimicking diet are prepared low in carbs and protein yet still high in healthy fats, such as olives and flax. All foods included are vegetarian, gluten-free and lactose-free. 

Plus, there is a specific combination of food that should be followed depending on the day for breakfast, lunch, dinner and even snacks. Your meals should have a combination of nutrients and calorie reduction to trick your body into thinking it is fasting. 

The meal kits usually include the following: 

  • Algal oil – a vegetarian-based supplement from marine algae that is rich in omega-3 fatty acid DHA and EPA. It is usually used to improve thinking skills and physical performance.
  • Dark chocolate crisp bar – a healthy dessert bar made with cocoa powder, almonds, chocolate chips and flax. Dark chocolate is a powerful antioxidant that can lower the risk of developing heart disease.
  • Herbal tea – has a type of flavonoid called catechins that can boost your metabolism and aid in breaking down fats. Some types of herbal teas to include in your diet can be spearmint, hibiscus and lemon-spearmint tea.
  • Kale crackers – considered to be a low-energy-density food. Eating kale crackers does not add many calories to your diet. Plus, kale crackers can help in boosting your energy while preventing you from gaining weight. This food has a mix of ingredients, such as flax seeds, nutritional yeast, kale, herbs and pumpkin seeds. 
  • L-Drink – is made of purified water, vegetable glycerin, natural flavours, citric acid and potassium sorbate. L-Drink is an energy drink that you can consume from Day 2 to Day 5 when your body starts the process of gluconeogenesis. 
  • Nut bars – eating protein bars or nut bars can effectively help in reducing weight as they can control your calorie intake. Also, meal bars are easy to carry which makes them a pretty accessible, healthy snack.  They are usually made from macadamia nut butter,  flax, honey, almond meal and coconut.
  • Olives – are one of the best low-calorie density foods to eat to manage weight. Olives are also a great source of healthy fats that can promote weight loss by making you feel full for longer hours. You can eat one pack of olives on Day 1 while two packs for Day 2 to Day 5. 
  • Soup blends – are an important part of the fasting-mimicking diet. Soup blends have a mix of flavoured soups, such as minestrone, quinoa, mushroom and tomato soup.

How to prepare?

  • Measure certain biomarkers – you should do this before starting the fasting-mimicking diet to track your progress. Some biomarkers can be blood glucose levels, ketones and weight changes every day. 
  • Set up your environment – it should be free from any low-nutritional value snacks.
  • Build support – you can also ask for support from your family and friends. You can depend on them to help you with your food restrictions and keep an eye on your dietary requirements.
  • Have better sleep – another factor to prepare your body is to sleep properly before you do the fasting-mimicking diet. You need to rest as you may feel more tired than usual when you follow the diet. 
  • Create and stick to the meal plan – all you need to do is to follow the eating schedules and the allowed foods to eat. 
Featured product offer
ProLon® Intermittent Fasting Bars
  • The recipe is a unique blend of macronutrients and micronutrients that has been researched for over 20 years at USC.
  • Created with proprietary formula made up of high-quality ingredients that don't activate the body's nutrient-sensing system.
  • Each box contains 12 bars--all plant-based, non-GMO, soy-free, dairy free, and gluten-free.

[1] https://health.usnews.com/wellness/food/articles/what-is-the-fasting-mimicking-diet 
[2] https://www.drlamcoaching.com/blog/benefits-of-a-fasting-mimicking-diet/ 
[3] https://prolon.co.uk/blogs/healthy-eating/surviving-the-prolon-fasting-mimicking-diet-fmd
[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4050641/ 
[5] https://www.healthline.com/nutrition/plant-based-diet-guide

Photograph: Woodsymoss/Envato
The information included in this article is for informational purposes only. The purpose of this webpage is to promote broad consumer understanding and knowledge of various health topics. It is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition or treatment and before undertaking a new health care regimen, and never disregard professional medical advice or delay in seeking it because of something you have read on this website.