ProLon Fasting Mimicking Diet Review: Does It Work for Weight Loss?

Healthline Diet Score: 3.5 out of 5

Fasting is a hot topic in health and wellness, and for good reason.

It’s been associated with a wide range of benefits — from weight loss to boosting your body’s health and life span.

There are many types of fasting methods, such as intermittent fasting and water fasting.

“Fast Mimicking” is a recent fasting trend that restricts calories for a set time period.

This article reviews the Fasting Mimicking Diet, so you can decide whether it’s right for you.


  • Overall score: 3.5
  • Fast weight loss: 3
  • Long-term weight loss: 4
  • Easy to follow: 4
  • Nutrition quality: 3

THE BOTTOM LINE: The Fasting Mimicking Diet is a high-fat, low-calorie intermittent fasting method that supplies prepackaged meals for five days. It may help you lose weight but is pricey and may not be better than standard intermittent fasting diets.

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What Is the Fasting Mimicking Diet?

The Fasting Mimicking Diet was created by Dr. Valter Longo, an Italian biologist and researcher.

He sought to replicate the benefits of fasting while still providing the body with nutrition. His modifications avoid the calorie deprivation associated with other types of fasting.

The Fasting Mimicking Diet — or “fast mimicking” — is a type of intermittent fasting. However, it differs from more traditional types, such as the 16/8 method.

The Fasting Mimicking protocol is based on decades of research, including several clinical studies.

Though anyone can follow the principles of fast mimicking, Dr. Longo sells a five-day weight loss program called the ProLon Fasting Mimicking Diet through L-Nutra, a nutrition technology company that he started (1).

How Does It Work?

The ProLon Fasting Mimicking Diet plan includes five-day, prepackaged meal kits.

All meals and snacks are whole-food derived and plant based. The meal kits are low in carbs and protein yet high in healthy fats like olives and flax.

During the five-day period, dieters only consume what’s contained within the meal kit.

Day one of the diet provides approximately 1,090 kcal (10% protein, 56% fat, 34% carbs), while days two through five provide only 725 kcal (9% protein, 44% fat, 47% carbs).

The low-calorie, high-fat, low-carb content of the meals causes your body to generate energy from noncarbohydrate sources after glycogen stores are depleted. This process is called gluconeogenesis (2).

According to one study, the diet is designed to provide 34–54% of normal calorie intake (3).

This calorie restriction mimics the body’s physiological response to traditional fasting methods, such as cell regeneration, decreased inflammation, and fat loss.

ProLon recommends that all dieters consult a medical professional — such as a doctor or registered dietitian — before starting the five-day fast.

The ProLon five-day plan is not a one-time cleanse and must be followed every one to six months to obtain optimal results.

SUMMARYThe ProLon Fasting Mimicking Diet is a low-calorie, five-day eating program meant to promote weight loss and provide the same benefits as more traditional fasting methods.

The ProLon meal kit is broken down into five individual boxes — one box per day — and includes a chart with recommendations on what foods to eat and the order in which to eat them.

A specific combination of food is provided for breakfast, lunch, dinner, and snacks, depending on the day.

The unique combination of nutrients and reduction in calories is meant to trick your body into thinking it’s fasting, even though it’s being given energy.

Because calories vary between days, it’s important that dieters do not mix foods or carry foods over into the next day.

All foods are vegetarian, as well as gluten- and lactose-free. The purchased kit comes with nutritional facts.

A five-day ProLon Fasting Mimicking Diet kit includes:

  • Nut bars. Meal bars made from macadamia nut butter, honey, flax, almond meal, and coconut.
  • Algal oil. A vegetarian-based supplement that provide dieters with 200 mg of the omega-3 fatty acid DHA.
  • Soup blends. A mix of flavored soups including minestrone, minestrone quinoa, mushroom, and tomato soup.
  • Herbal tea. Spearmint, hibiscus, and lemon-spearmint tea.
  • Dark chocolate crisp bar. A dessert bar made with cocoa powder, almonds, chocolate chips, and flax.
  • Kale crackers. A mix of ingredients including flax seeds, nutritional yeast, kale, herbs, and pumpkin seeds.
  • Olives. Olives are included as a high-fat snack. One pack is provided on day one, while two packs are provided on days two through five.
  • NR-1. A powdered vegetable supplement that delivers a dose of vitamins and minerals that you wouldn’t normally consume during a traditional fast.
  • L-Drink. This glycerol-based energy drink is given on days two through five when your body has started gluconeogenesis (begins to create energy from noncarbohydrate sources, such as fats).

Dieters are encouraged to only consume what is contained within the meal kit and to avoid consuming any other foods or beverages with two exceptions:

  • Soups can be flavored with fresh herbs and lemon juice.
  • Dieters are encouraged to stay hydrated with plain water and decaffeinated teas during the five-day fast.

SUMMARYThe ProLon meal kit contains soups, olives, herbal teas, nut bars, nutritional supplements, chocolate bars, and energy drinks. Dieters are encouraged to only eat these items during their five-day fast.