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 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?
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.
Can Food Supplements Cause Weight Loss?
There exist several over-the-counter (OTC), food-based weight loss supplements that don't require a prescription, and which have medical research backing.
Dietary fiber is associated with weight loss in clinical trials, especially when combined with caloric restriction.
A landmark medical study found that moderate caloric restriction (750 calories per day below baseline) combined with dietary fiber intake (a minimum of 20 grams per day) caused an average weight loss of 16.03 pounds over 6 months. That’s a pace of 32 pounds per year of weight loss in overweight individuals simply by adding fiber to a moderately-restricted-calorie diet.
The fiber supplement we recommend is SuperGut Fiber Mix. It contains a clean and effective formulation: a blend of three different types of unflavored dietary fiber and zero additive ingredients. It can be mixed into liquids or foods. Interested consumers can buy SuperGut fiber at this link to the product page on the brand's website.
We recommend using two fiber mixes per day, which provides 16 grams (g) of total fiber. Diet should provide the remaining fiber necessary to meet the 20 g minimum threshold.
MCT oil is derived from coconuts, quickly absorbed by the body and increases metabolic rate, which causes fat loss. A meta-study on MCT oil documented weight loss of 1.12 pounds over 10 weeks. This equates to a potential annualized weight loss of 5.84 pounds with MCT oil supplementation.
We recommend Bulletproof MCT Oil as our top MCT oil product, because it has a clean and effective formulation. The only ingredient is MCT oil derived from coconuts, and the product has no questionable additives. Interested consumers can buy Bulletproof MCT Oil at this link to the product page on the brand's website. This supplement only costs $15.50 for over a month's worth of product.
The effective dose range of MCT oil for weight loss (based on the medical review) is 1.7 g to 10 g per day. Bulletproof's MCT oil provides 14 g in one tablespoon, so around two-thirds of one tablespoon should be a maximally-effective dosage.
We're not suggesting that these products are as effective as ProLon for weight loss; just that it may be worthwhile for a patient to discuss these supplements with their doctor given their documented efficacy and lack of side effects. They may also be used in addition to a weight loss program like ProLon.
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