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ProLon Fasting Mimicking Diet Review: Pros, Cons, and Effectiveness
Published on February 18, 2021
ProLon is a diet that uses specific foods to achieve the health benefits of fasting without actually fasting. There is significant evidence this diet might improve overall health, but it would not be my first choice for losing weight.

Pros
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Cons
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What Is the Fasting Mimicking Diet?
The ProLon Fasting Mimicking Diet is the first meal program that allows you to get the benefits of fasting, while still eating. “ProLon” stands for “Promoting Longevity and Healthspan.”
The diet was developed by Dr. Valter Longo, the director of the Longevity Institute at the University of Southern California. Dr. Longo is a well-respected health researcher.
The ProLon diet was developed based on Dr. Longo’s research about how cells sense food.
With this understanding, he was able to develop a formulation that “tricks” the cells into thinking there is no food available and that the body is fasting.
This allows you to get all the benefits of fasting without actually fasting.
The goal of the program is to:
- Promote cellular renewal
- Support metabolic health
- Enhance clarity and performance
- Encourage fat focused weight loss
The program is not weight-focused, although many do lose weight. The main goal is to increase longevity and health by cleaning up harmful cells and debris in the body.
This process, called autophagy, is believed to reduce the risk of disease, improve health, and optimize brain function. (1)
ProLon Fasting Mimicking Diet’s Scorecard
The ProLon Fasting Mimicking Diet was objectively evaluated by a dietitian based on the following criteria:
Evidence-Based | 5/5 |
Easy to Follow | 5/5 |
Customization | 1/5 |
Sustainability | 3/5 |
Safety | 4/5 |
Value for the Price | 3/5 |
Accountability | 1/5 |
Overall Rating: | 3.1/5 |
How It Works
ProLon involves a 5-day meal program that is a combination of specific nutrients in precise quantities that will nourish you but are not recognized as food by your body.
At the start of the program, you receive a box of plant-based, gluten-free packaged food that includes a combination of soups, supplements, and drink mixes.
The diet provides between 725 and 1090 calories, depending on the day you are on. It is designed to meet 34–54% of your normal calorie intake.
For 5 days you eat only the food provided in the boxes. Some of the foods you might eat on the ProLon diet include:
- Tea
- ProLon snack bars
- Plant-based soups, like minestrone and tomato
- Kale crackers
- Appetite suppressing drinks
- Olives
- A variety of multivitamins and other supplements
After the 5 days, you are supposed to ease back into regular meals a little at a time. For optimal results, it is recommended that you do three cycles of ProLon for consecutive months.
Evidence to Support Claims
There is substantial evidence of the benefits of intermittent fasting, from stress management to better brain health, and improved cellular function. (2)
It may also be beneficial for weight loss and improving body composition. (3)
Although fasting has benefits, not eating for extended periods of time has downsides such as decreased immune function, fatigue, and low blood sugar or blood pressure.
It is also difficult to stick with for most people.
Considering the benefits and challenges of fasting, having an alternative in the ProLon diet is a great way to circumvent some of those downsides.
The ProLon diet was developed by health researchers and has quite a bit of evidence to support its claims.
A 2017 study compared the effect of ProLon versus an unrestricted diet on various health markers. (4)
One hundred subjects followed either a normal diet or three rounds of ProLon for a three-month period.
Those on the ProLon diet had significantly reduced body fat, lower blood pressure, improved blood sugar, lower inflammation, and better blood lipid levels.
Subjects lost an average of 6 pounds. These results were sustained for up to 115 days after following the program.
There is on-going research to continue to understand the benefits of ProLon and how it can improve health.
Sustainability
ProLon is super easy to follow, you just eat what is provided in the box for 5 days.
The main challenge to following this diet would be hunger, although many of the reviews I read said most people do not feel very hungry on the diet.
Since it is only five days, it seems like you could power through it.
My other concern would be that people might binge once the five days are over, reversing any benefits they may have achieved.
If you can slowly transition onto a healthier diet once you are done with your cycle, you might be able to maintain some of the benefits.
The diet is also not customizable for specific allergies or dietary preferences. The food included is plant-based, non-GMO, and gluten-free, so it can meet most people’s food restrictions.
Those with allergies to nuts, seeds, or oats should avoid this diet as it contains those ingredients.
Accountability
There is no accountability mentioned on the ProLon website.
Only one of the reviews I read said that the program did come with a consultation with a dietitian or nurse, but I was not able to find this information on their website.
Like most diet protocols out there, I am certain there are user-created Facebook groups for the ProLon diet, but the quality of these can vary if they are not regulated.
Value for the Price
ProLon offers three different pricing levels for the diet. They are:
- Monthly subscription for $189: You will receive a new 5-day ProLon box every month.
- One-time order for $199: Just one box of the 5-day ProLon diet.
- One-time order + bars for $224: This includes the ProLon intermittent fasting bars along with the 5-day box.
Since ProLon is designed to replace all of your food for 5 days, this is a fairly moderate price.
This diet is fairly unique, for those looking for specific health benefits, this price may be worth it.
Safety
ProLon is safe for most healthy people. But it is recommended you speak to your doctor before starting the diet.
Those with blood pressure concerns or diabetes should be cautious when trying a diet like this due to the low calorie and carb allowance.
This would be a particular concern if you are on medication for either of these conditions. I would recommend medical supervision if you want to give it a try.
Those with allergies to nuts, seeds, oats, or any of the ingredients in the box should not do ProLon.
It is not recommended for pregnant or breastfeeding women. I would also avoid it if you have a history of eating disorders.
How It Compares
As far as I am aware, there are no other fasting alternative diets that work in the same way as ProLon.
The health benefits provided by this diet in terms of longevity and cellular repair are unique.
Trying intermittent fasting on your own can provide similar benefits and there is currently no evidence that ProLon is any better than just regular fasting.
Fasting with food might just be easier to sustain for a longer period of time.
If you are curious about fasting, I would recommend starting slowly with a 16:8 protocol where you fast for 16 hours and eat during an 8-hour window.
The Bottom Line
If you are primarily looking for long-term sustained weight loss, ProLon is probably not your best choice.
Although you might lose weight during the 5 days you are on the program due to drastic calorie restriction, once you being to eat normally again you can expect to gain this weight back.
The theory behind ProLon is definitely interesting and the program may prove to have long-term health benefits.
I would recommend this diet to someone who is primarily interested in improving overall well-being and longevity with periodic fasting.
At WellnessVerge, we only use reputable sources, including peer-reviewed medical journals and well-respected academic institutions.
- Identification of natural products with neuronal and metabolic benefits through autophagy induction:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5240827/ - Metabolic Effects of Intermittent Fasting:
https://www.annualreviews.org/doi/abs/10.1146/annurev-nutr-071816-064634 - Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism:
https://pubmed.ncbi.nlm.nih.gov/15640462/ - Fasting-mimicking diet and markers/risk factors for aging, diabetes, cancer, and cardiovascular disease:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6816332/