What Is ProLon?
ProLon is a scientifically developed and clinically tested periodic meal plan that promises to mimic the effects of fasting, while still providing you with enough plant-based nourishment—including essential vitamins and amino acids—to remain satisfied throughout the process.
The result? When taken just five consecutive days per month, the company tells us it’s been proven to help quickly decrease weight, body fat, and visceral fat; maintain healthy glucose and cholesterol levels, promote healthy blood pressure, decrease IGF-1 (an aging marker), preserve bone density, and “positively impact related health risk factors.”
And compared to water-only fasting, the company tells us that ProLon is convenient, doesn’t require ongoing lifestyle changes, and has been proven safe.
If you’re tired of the dieting merry-go-round and are looking for a quick, easy solution for losing weight, all of these claims might sound wonderful. But what kinds of results can you realistically expect with ProLon, and is it worth your hard-earned money?
Let’s start answering your questions by taking a deeper look at the program.
How Does ProLon’s Fasting Mimicking Diet (FMD) Work?
Created in collaboration with some of the world’s best food scientists and chefs, ProLon’s meals come in five boxes (one for each day) that consist of a variety of plant-based foods like energy bars, soups, snacks, drinks, and dietary supplements that are low in carbohydrates and proteins, while containing good fatty acids.
According to the program’s website, there are no additives, preservatives, or chemicals in these foods, which provide between 770 and 1,100 calories per day. The company tells us that your body won’t recognize these calories as food, thereby helping you to maintain a fasting mode, without actually fasting.
However, this reduced intake has been clinically shown (more next), according to the website, to “trigger a set of protectionist measures that the body developed during natural selection, when food was scarce and not easy to find and store. It allows your body to optimize its performance, rejuvenate its cells, and thrive under such circumstances.”
Specifically, we’re told it can reduce IGF-1, glucose, and inflammation and aging markers.
Depending on body weight, baseline markers, and other health measurements, low-risk or healthy individuals are recommended to undergo ProLon’s five-day fasting periods two to three times a year, while those who are considered high-risk can undergo them three to 12 times.
During these periods, customers are instructed not to consume any other foods, or any additional liquids other than water. When you’re finished, you’ll have a one-day transition period, after which you can resume your normal eating habits.
Have Fasting Mimicking Diets Like ProLon Been Clinically Proven?
Fasting mimicking dieting was the brainchild of Valter Longo, who developed the program at the University of Southern California.
Along with the university, he's also an owner of the company behind ProLon, called L-Nutra, although he’s emphasized in the past that he receives no money from the sale of these products.
Overall, the plan has undergone three clinical studies:
One completed on periodically fed yeast, which was shown to have a longer lifespan than those who were fed normally.
Another completed on mice, which were fed a reduced calorie and protein diet for four days per month. In the end, they experienced “improved metabolism and cognitive function, gradual weight loss, muscle rejuvenation, higher bone density, 40% fewer malignant lymphomas, immune system regeneration, and longer average, though not absolute, life expectancy.”
A third study conducted on 38 individuals (19 who underwent FMD and 19 who acted as the control). Those on FMD were reported to experience an “average 3% reduction in weight, a reduction in visceral fat, a reduction in C-reactive protein, and rejuvenation for the immune system.”
We also encountered 67 clinical studies related to fasting mimicking diets on the National Institutes of Health’s PubMed, referencing everything from its effects on tumors and multiple sclerosis to cancer and circadian rhythm.
Will ProLon Cause Potential Side Effects?
In these studies, most participants reported only mild or no adverse effects on the fasting days, although none of these side effects were specified.
However, the company emphasizes in several places on their website that ProLon is not for everyone and should only be used by “healthy individuals who want to optimize their health and wellbeing.” It shouldn’t be used by those under 18, women who are pregnant or nursing, those who are allergic to soy or nuts, those with a BMI less than 18, or those with diabetes or significant cardiac disease.
Outside of what’s provided in each box, the company emphasizes that no additional multivitamins or supplements should be taken during the diet period. And, unless approved by a licensed physician, ProLon should never be combined with glucose lowering drugs, such as metformin or insulin.
To make sure you’re a candidate, you’ll need to take a short self-assessment evaluation when purchasing (indicating age, height, weight, BMI, any prescription medications, and so forth), or reach out to your healthcare provider. The website seems to be strict about this, as it rejected a mock order during our research after only indicating that we took prescription medication.
How Much Does ProLon Cost?
The price you pay for ProLon depends on the number of boxes you purchase at a time:
- 1-2 boxes: $299 per box
- 3-6 boxes: $250 per box
All orders come with free standard shipping and no sales tax, except in CA.
In addition to the self-assessment we discussed in the previous section, once your purchase is complete, you’ll also need to complete a guidance call with the company’s dietitian or nurse practitioner to finish processing your order.
ProLon offers a 30-day refund policy on all unopened boxes, less S&H, any discounts received for purchasing multiple boxes at once, as well as a 15 percent per-box restocking fee.
In order to speak to a representative or process a refund, you’ll need to contact customer support at 323-580-6855 or firstname.lastname@example.org.
What Are Dieters & Professionals Saying About ProLon?
While there seems to be mounting clinical evidence that infrequent fasting mimicking diets could provide some measure of weight loss and other potential benefits, there is some concern that this doesn’t extend much beyond calorie restriction.
Specifically, that the control group in the previously noted human study didn’t reduce their calorie intake, so it’s not quite clear whether FMD’s benefits stemmed from fasting or from calorie restriction.
Interviewed for a 2017 Forbes article, David L. Katz, founding director of the Prevention Research Center at Yale University, explained it this way:
“As far as I can tell, this proves nothing about fasting. Going days without food produces a calorie deficit, and that causes weight loss. Weight loss, in turn, ameliorates all of the metabolic markers studied here. So, what we've got is: eating less leads to short-term weight loss, and weight loss improves diverse metabolic markers in the short term. Which part of that didn't we know already? To show a direct benefit of fasting, it needs to outperform an alternative diet pattern matched for calories. That was not done here.”
Furthermore, after interviewing several Registered Dietitians, Korin Miller, writing for Women’s Health, delivered the following verdict:
“Don't expect the Fasting Mimicking Diet to give you long-term results. If weight loss and maintaining that goal weight are your main objectives, experts recommend taking a closer look at your overall diet instead and figuring out where you can make smarter choices.”
Despite this, blogger Quantified Bob perused the program’s studies and came up with his own FMD (not ProLon specifically) in April 2016, finding that it reduced his body fat by about two percent, while actually increasing his muscle mass. He also reported good energy and mental clarity during the process.
After undergoing blood work, he found his white blood count went down, his testosterone levels increased by one point, and his stress (cortisol and adrenal) and liver levels were “optimized.” Overall, he reported being “very impressed” with his FMD results.
Finally, Erin Van Der Meer tried out ProLon specifically, noting that she’d “100 percent do it again,” since it was simple and helped her face, stomach, and thighs look slimmer. However, she also noted that the gained back 25 percent of the weight she lost once she resumed normal eating.
Our Final Thoughts About ProLon
Based on the available clinical evidence (although preliminary), as well as reports from actual users, it appears that a fasting mimicking diet like ProLon could help you lose a quick few pounds, as well as boost several biological markers associated with good health.
But unless you’re clearly someone with a lot of background knowledge (like blogger Bob from earlier), only you can decide whether this weight loss is worth the $250 or more price tag for each pre-filled box.
As consumers ourselves, we’re focused on helping you get the most bang for your buck. Which is why we’d strongly recommend speaking with your healthcare provider about ProLon, and whether or not it might meet your expectations (and budget), prior to placing your order.
The company strongly emphasizes on their website that the program should only be conducted under the supervision of a doctor anyway, so this will provide an opportune time to address more than one issue during the same visit.