ProLon Review: A Fasting Plan That Lets You Eat?

ProLon Review: A Fasting Plan That Lets You Eat?

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Disclaimer: None of the information in this article constitutes medical advice, and is just the opinion of the writer(s). We recommend that patients follow their doctor’s guidance in regard to weight loss and fasting.

ProLon is a fasting meal service, which sounds like an oxymoron. The brand describes their service as “the fasting plan that lets you eat.” The company also claims that their offering “is based on over 20 years of scientific research and over $34 million in R&D.”

But is ProLon actually proven in clinical studies to cause weight loss? How much weight loss is possible? How do the weight loss effects of ProLon's plan compare to other popular weight loss meal programs like Jenny Craig? And how do real users describe the effects of ProLon?

In this article we'll answer all of these questions and more as we review a clinical trial on ProLon to determine if the plan can cause weight loss. We'll compare its weight loss effects to other popular weight loss meal programs.

We'll also review the ingredients in a ProLon meal to give our take on whether or not the program is healthy, and share real, unsponsored ProLon user reviews including a before-and-after video.

Does ProLon Cause Weight Loss?

ProLon clinical efficacy claims

ProLon is a fasting-mimicking diet, and the brand claims it can cause 5.7 pounds of weight loss in 5 days.

Fasting-mimicking diets significantly reduce calorie and sugar intake to replicate the metabolic benefits of fasting. A clinical trial published in the Science Translational Medicine journal tested whether ProLon could cause weight loss.

Trial participants on ProLon lost around 7 pounds over 3 months by using the program for 5 days of the month.

We will conclude from this research that ProLon is likely to be effective for weight loss. That being said, any diet that restricts calories below baseline can cause weight loss, and we don't consider this trial to be particularly well-designed because there is no comparison to another diet model such as intermittent fasting.

We commend ProLon for funding legitimate medical research proving their plan works, but we would not recommend their program based on these results alone. 

ProLon vs. Other Diet Programs

ProLon isn't the only diet plan that's been studied in legitimate medical research. An extensive 2016 medical review compared the efficacy of commercial weight loss programs. The study authors reviewed data on Weight Watchers, Jenny Craig, Nutrisystem, MediFast and Optifast.

Jenny Craig was found to be the most effective weight loss program, with an average weight loss 4.9% greater than nutritional counseling alone over the course of one year. This equates to weight loss of 9 pounds for a 200 pound person.

We would consider ProLon likely to cause greater weight loss than all of the programs reviewed in this study, given that ProLon caused 7 pounds of weight loss in 3 months, which equates to a potential annualized weight loss of 28 pounds.

We also consider ProLon to be healthier than Jenny Craig as it contains mostly whole foods ingredients and Jenny Craig meals are more processed.

Based on the existing research, we would recommend ProLon over other commercial diet programs.

ProLon Before and After Video

One of the most popular questions consumers have about any diet plan is: what do real users look like before and after?

Thankfully, a YouTube creator named Zoe Miyoko tried ProLon and shared before-and-after images. We've timestamped the below video to start at the before-and-after section:

Is ProLon Healthy?

ProLon Nut Bar ingredients

The above ingredient label is from ProLon's "Nut Bar."

ProLon has a Nutritional Fact Information page on their website with Nutrition Facts labels for all of their products. For the most part, their food products are sourced from whole foods ingredients and we would consider them to be healthy and nutritious.

All ProLon soups are composed entirely of whole foods ingredients and we would recommend any of their soups from a nutritional perspective. The soups are formulated with a plant base like butternut squash, and contain spices such as oregano, garlic and chives.

ProLon snacks are also decently formulated, though there are some ingredients in their snacks we would recommend avoiding (especially to those seeking weight loss), such as cane sugar in their  fasting bar called “L-Bar” and citric acid in their Almond & Kale Crackers.

As detailed in a medical review published in the Toxicology Reports journal, citric acid is a food additive used as a flavor enhancer and preservative which is typically manufactured from a fungus, and which can cause significant whole-body inflammatory reactions in a small subset of the population.

ProLon also has a Drinks section including custom drinks and teas. We would recommend any of their teas which are sourced exclusively from organic herbal tea ingredients. We would recommend avoiding their “L-Drink” which contains natural flavors

As we documented in our review of another nutritional brand called Pruvit, there is some medical research suggesting that natural flavoring agents may be harmful to human health.

Overall we consider ProLon's ingredients to be healthier than most diet plans we've reviewed on Illuminate Health, but we would only recommend ProLon's soups and teas because they're free of questionable additives.

Real, Unsponsored ProLon User Review

One of the most popular YouTube reviews of the ProLon diet is published by a creator named Jason Sani. He shares his experience and results on the ProLon diet:

Is Fasting Healthy?

At this point in the review, readers are likely wondering whether fasting (rather than a "fasting-mimicking diet") is healthy, and whether it can also cause weight loss. A medical review published in 2021 examined data from clinical trials on various types of fasting, from standard fasting to intermittent fasting to the “5:2 diet" (which entails fasting for two days of the week).

The researchers found that fasting had favorable effects on insulin resistance and blood pressure, and also caused weight loss in overweight and obese patients. 

As we explained in our DoFasting supplements reviews article, there is medical evidence that intermittent fasting causes weight loss irrespective of calories consumed, because of favorable metabolic changes. Fasting is a slight stressor to the body which can cause epigenetic changes that improve health. It’s also logical that the human body would be evolved to adapt to variable periods of fasting, because humans did not evolve with constant access to food.

Intermittent fasting, which refers to fasting for a fixed period of hours per day (typically 16), is effective for weight loss. A meta-study examined data from 27 individual trials on intermittent fasting and weight loss. In every single trial, participants lost weight. The amount of weight lost relative to baseline weight ranged from 0.8% to 13%, but the trials were all short in duration, ranging between 2 and 26 weeks. These are incredibly impressive results.

We would recommend that patients speak with a doctor prior to fasting, because it may not be safe for all people. However this data suggests that consumers on a budget may want to consider simply fasting instead of using ProLon.

Our Clean Weight Loss Picks

There are food-based nutrients which have been shown in medical studies to be effective for weight loss.

Dietary fiber was shown in a medical review published in The Journal of Nutrition to cause 16 pounds of weight loss in 6 months when combined with moderate caloric restriction (750 calories per day below baseline).

MBG Organic Fiber Potency+ is our top fiber pick because it's certified organic, provides 7 g of fiber per serving and costs under $1.85 per serving at the time of updating this article.

MCT oil was shown in a meta-study to cause more than one pound of weight loss over 10 weeks. This equates to potential annualized weight loss of 6 pounds per year with less than one tablespoon's worth of MCT oil per day.

Bulletproof MCT Oil is our top MCT oil product, because the only ingredient is MCT oil derived from coconuts. and it currently costs only $15.50 for over a month's worth of product.

Ginger intake "significantly decreased body weight" according to a 2019 meta-study on ginger and weight loss that analyzed data from 14 clinical trials.

Pique La Ginger is our top ginger product, because it's an organic tea in convenient crystallized form, and all that's needed is to pour the powder into a glass and add hot water.

All three of the products mentioned in this section are entirely free of additive ingredients that we consider to be unhealthy or unsafe.

ProLon Pros and Cons

Here’s our opinion of the pros and cons of the ProLon diet:


  • Healthy formulations
  • Fasting has metabolic benefits
  • Proven in a clinical trial to work
  • Better than other diet programs


  • Some products contain questionable additives
  • No proof of efficacy over regular fasting
Stay up-to-date on our research reviews


ProLon has published convincing medical evidence that the fasting-mimicking diet has similar metabolic benefits to fasting. The diet plan is proven to cause weight loss, and appears to be more effective and healthier than other commercial diet programs such as Nutrisystem and Jenny Craig.

We cannot identify any medical studies proving that ProLon is more effective than intermittent fasting, or than regular fasting, so we do not recommend the program overall. Their meal plans also contain a few additive ingredients that we recommend avoiding.

For consumers that are set on using a commercial diet program, we would recommend ProLon over the alternatives.