The ProLon Fasting Mimicking Diet (FMD) has gained popularity as a structured approach to experiencing the benefits of fasting while still consuming food. This article delves into the details of the ProLon diet, examining its components, potential benefits, and drawbacks based on user reviews and scientific studies.
Introduction to the ProLon Diet
The ProLon diet is a 5-day program designed to nourish the body while encouraging benefits associated with prolonged fasting, such as cellular rejuvenation. It is a prepackaged meal plan that claims to offer your body the nutrients it needs while avoiding activating your food sensing pathways so that you can get the benefits of prolonged fasting. Developed by Dr. Valter Longo, it is a nutrition program that puts your body into a state of fasting while still nourishing your body with essential nutrients.
What is the ProLon "Fasting Mimicking Diet?"
The ProLon diet is a 5-day prepackaged plan that features vegetable-based soups, energy bars, snacks, herbal teas, and supplements. The diet consists of an ultra-low-calorie blend of proteins, carbohydrates, fats, and nutrients that’s meant to trick the body into thinking it is fasting, but with less discomfort or risk than a true water-only fast. The ProLon diet is designed to offer sufficient nutrients to sustain your body while keeping calories low enough so you’ll receive the benefits of being in a fasting state. It contains no animal protein, low amounts of plant protein, very low amounts of saturated fat, high amounts of unsaturated fats, very low amounts of sugars, and high amounts of complex carbohydrates.
The Science Behind ProLon
Dr. Valter Longo, founder of L-Nutra and creator of the Fasting Mimicking Diet (FMD), developed the nutrition program to help patients lose weight and, more importantly, reduce cholesterol, lower age-related disease risk, boost metabolic health, and promote longevity. Prolon’s program has also been clinically tested by the laboratory of Dr. Longo and Keck Hospital at the University of Southern California, which is a big deal-something many other fasting programs and cleanses can’t claim.
Dr. Longo and his team at The University of Southern California have been working with pathways in the body called “nutrient-sensing pathways.” The FMD works by avoiding triggering these pathways, which tell the body it is in a fed state. The nutrient-sensing pathways control autophagy, the “housecleaning” of our body’s cells.
Read also: Is the ProLon Diet Worth It?
While there are many different signaling factors in the “nutrient-sensing pathways” involved with cellular fasting, the 3 primary nutrient-sensing pathways that ProLon and fasting down-regulate are IGF-1, mTOR, and PKA. The process is complex, and each pathway can interact with other pathways, but in general, PKA responds primarily to sugar and carbohydrates, while IGF-1 is primarily responsive to protein (and more strongly triggered by animal protein), and mTOR is triggered by IGF-1 and amino acids.
What's Included in the 5-Day Program?
The super-structured program comes in one-day and five-day options. The box contains five separate boxes for each day, each filled with your ‘meals’ and supplements. The meals come in the form of plant-based soups, bars, snacks, specific drinks, and supplements. You’re also allowed unlimited water and one cup of black coffee (minus the creamer) per day. Each day, you’re consuming around 700 to 1,000 calories, depending on the day.
The box also includes a “menu” that outlines everything you’ll eat (and are allowed to drink) for each day. Each day starts with a nut-forward bar, which is pretty satisfying and helps keep you full. Lunch is usually a soup of some sort, and in the afternoon, on three of the days, you get either kale and almond crackers or a pack of olives. Dinner is another soup, and on days one and two, you get a small “dessert.” You’re also given a glycerin liquid to mix with water, which “provides the body with an alternate energy source to use instead of lean body mass during days 2-5 of the fast,” as well as several herbal tea bags.
What's On the Menu?
Each day, you’ll be eating one (very tasty) nut bar from breakfast, one soup for lunch and one soup for dinner, delicious olives and/or kale and flaxseed crackers for your snack, and lots of herbal teas; and on a few of the days you even get dessert with a delicious “choco crisp’ bar. For days 2-5 you’re also drinking something called an “l-drink” throughout the day, that’s designed to fuel and protect lean muscle mass as your body burns fat.
Day-by-Day Breakdown
Day 1: The first day’s diet contained 1,150 calories. It was hard, but not impossible.
Read also: Is the ProLon Diet Safe?
Day 2: Fat burning & ketogenesis - fat-burning ramps up, contributing to the initiation of ketogenesis (ketone production). By the end of this day, ketosis may occur. When your body reaches ketosis, it switches from burning glucose (from carbohydrates) to burning fat for energy, producing ketones as a byproduct, which can be used as an alternative fuel source. This can lead to fat loss, appetite recalibration, and a variety of other benefits.
Day 4: Cellular rejuvenation - cellular cleaning/renewal and fat-burning continues.
Day 5: Renewal & change: once you complete day five, cellular renewal continues (and you’ll continue to experience all of the benefits in the days post-cleanse.
Taste and Texture of ProLon Foods
It’s not the best food I’ve ever had, but I didn’t expect it to be. I was surprised by how good some of the soups, crackers, and olives were. I expected to feel famished and repulsed by the soups' flavor (or lack thereof). While I definitely wouldn’t choose the Carrot Ginger soup again, I really enjoyed the Green Pea and Chives and Lentil Curry soups and would eat them even if I wasn’t on the FMD diet. The kale and almond crackers and olive packs were also delicious. I’m already hunting for alternatives on Amazon and Costco so I can enjoy them every day. I was also impressed by the creamy consistency of the soups. I had imagined they’d be chalky (like some powdered greens supplements), but they weren’t at all.
Personal Experiences and Results
By day six, I had lost five pounds. While most of this was likely water weight, I haven’t regained it yet. I attribute this to the transition diet (days six and seven), which is recommended after the program. The brand suggests slowly introducing easy-to-digest foods like beans, grains, and lean protein in the two days following completion. Despite the significant caloric reduction, I didn’t feel as exhausted and malnourished as I’d anticipated. The third and fifth days were challenging, but that was mostly due to temptation from others around me who weren’t doing the cleanse.
Read also: Comprehensive Guide to Tea Fasting
Another concern I had was how the reduced calories would impact my sleep. Fortunately, like many others, my sleep was OK. The fifth night was rough, and my Oura Ring called me out for my lack of “readiness,” but I figured one night of subpar sleep was worth the other benefits. Plus, I didn’t feel sluggish or zombified the next day, which I attribute to the FMD benefits.
Exercise During ProLon
In theory, yes. In fact, the brand suggests you maintain your normal lifestyle as much as possible while on the program. However, I kept my workouts low-impact (i.e., walking) and skipped my usual heated Pilates fusion classes and weight training. These classes are heated to 105°F and combine bursts of cardio and HIIT. I was worried about feeling faint, and they significantly increased my appetite. With brisk walks on an incline for three of the five days, I felt OK (I skipped days three and five because I was more tired and lightheaded).
You’ll need to avoid strenuous physical activity during the five day cleanse. Because your body isn’t getting as many calories as it typically would, you simply don’t have as much energy to expend; so it’s important to keep physical activity light during this period. Gentle walks and light yoga/stretching are fine, but harder workouts should be avoided during the duration of program.
Potential Benefits of the ProLon Diet
ProLon is a fantastic program, and I highly, highly recommend it. I often will incorporate a Prolon cleanse into my clients’ holistic nutrition plans, and I recommend it to anyone looking for a health reset. It’s great if you’ve been struggling with sugar cravings, brain fog, low energy, or bloating/gut issues.
The ProLon diet may improve your cardiovascular health, support your metabolic health, and help you lose weight while maintaining lean muscle mass. It can:
- Support healthy aging
- Increase your metabolism
- Reduce inflammation
- Lower your blood pressure
- Help you lose weight while maintaining lean muscle
- Encourage cellular rejuvenation
The FMD reduced markers of inflammation and promoted a healthier gut microbiome.
Clinical Study Results
Three FMD cycles reduced body weight, trunk, and total body fat; lowered blood pressure; and decreased insulin-like growth factor 1 (IGF-1). No serious adverse effects were reported.
A post hoc analysis of subjects from both FMD arms showed that body mass index, blood pressure, fasting glucose, IGF-1, triglycerides, total and low-density lipoprotein cholesterol, and C-reactive protein were more beneficially affected in participants at risk for disease than in subjects who were not at risk.
Potential Drawbacks and Considerations
Due to the specific foods required, it can be hard for people with food allergies or strong food preferences to follow the ProLon diet. The ProLon diet may also not be a good fit for those on a tight budget due to the kit’s high cost. Fasting isn’t appropriate for everyone, and you may experience dizziness, fatigue, headaches, and difficulty concentrating while following the ProLon diet. Also, you shouldn’t do the ProLon diet if you’ll be undertaking strenuous activities or spending time in extreme temperature environments, including saunas and hot tubs. It’s important to remember that the ProLon diet isn’t a long-term, daily dietary solution for health complications.
Individuals with allergies to any of the ingredients included in the foods may experience hives, rashes, or difficulty breathing if they ingest these items.
Cost of ProLon
A 5-day ProLon fasting kit costs approximately $175, or $35 per day. The research supporting the benefits and associated weight loss of the ProLon diet was specific to individuals following the 5-day program once a month for 3 months, which totals $525.
Prolon is eligible for purchase and reimbursement with HSA/FSA - partnered with TrueMed. Programs like health savings accounts (HSA) and flexible spending accounts (FSA) enable individuals to allocate pre-tax money for qualified healthcare expenses.
ProLon vs. Other Fasting Methods
Fasting - a complete absence of food intake. Intermittent fasting or alternate-day fasting - a long-term practice of fasting every other day, with standard food intake on non-fasting days. Fasting mimetics - pharmacological agents that trigger some of the effects of fasting. Caloric restriction - A 20-40 percent reduction in standard calorie intake, but a standard intake of micronutrients
Intermittent fasting involves designated periods of the day without eating. Among the various protocols, the 16:8 method is the most popular. In this approach, individuals fast for 16 consecutive hours, consuming only calorie-free beverages like water or plain tea, followed by an 8-hour eating window. During this time, they focus on healthy food choices without the need to count calories. The Fasting Mimicking Diet (FMD), on the other hand, works differently. It includes specific foods designed to prevent the activation of pathways that break the fasting state.
Who Should Avoid ProLon?
It’s important to note that Prolon is not for everyone, especially athletes, those with eating disorders, or individuals with certain health conditions. The fasting-mimicking diet is contraindicated during pregnancy, breastfeeding, in children, and anyone with a history of an eating disorder. Other medical conditions may also prohibit its use.
Important Considerations
It’s always recommended to consult your physician or healthcare provider before starting a new diet or lifestyle shift. Fasting is not appropriate for everyone.
Frequently Asked Questions
How much weight do you lose on ProLon?
Most of the research into weight loss and the other benefits of fast-mimicking diets such as ProLon involve rodents or testing at the cellular level. A 2021 study found that weight loss might occur during the fast-mimicking period, but it was not sustainable for the long term. More high-quality, long-term human studies are needed to determine the effectiveness of the ProLon diet for weight loss.
While I prefer to view weight loss as a secondary benefit to all the immense overall health and longevity benefits you get with Prolon, yes - most people lose around 5 lb. on average after completing the 5-day program.
How long should you be on the ProLon diet?
The ProLon meal plan lasts for 5 days with a day of transitional diet after. It’s important to discuss the best frequency for you with a licensed healthcare professional. ProLon generally recommends doing it once a month for 3 months in a row the first time you do the diet. After that, depending on your health goals, you could do it once a month for up to 6 months or once every 3 months.
What are the side effects of the ProLon diet?
You may have fatigue, headaches, dizziness, or difficulty concentrating while doing the ProLon diet.
Can you drink coffee on the ProLon diet?
Although ProLon recommends avoiding caffeine while following the diet, you can have 140 milligrams of caffeine each day. According to ProLon, this is equivalent to about one 8-12-ounce cup of traditionally brewed black coffee, two cups of black or green caffeinated tea, or six cups of traditionally brewed decaffeinated coffee.