Fasting Mimicking Diet — My Experience

I first heard about the Fasting Mimicking Diet on the Rich Roll Podcast. I fast a couple of times a year for three or more days. I do it for a few reasons. There is evidence that fasting can thwart off any cancer forming in the body, can perpetuate cellular regeneration, and can be a healthy way to burn fat. I also like the psychological benefit of overcoming the challenge. When I heard that a scientist had done a bunch of research into developing a fast that tricks your body into all of the benefits of fasting but with food I was intrigued. It’s also plant based which is perfect for me given I’m vegan. This is my experience.

The FMD comes with all the food and supplements that is delivered in a very organized packaging. Each day’s menu is in its own box. There is extensive packaging throughout. Prolon was very brand conscience with its logo on every individual's item down to the flag on the tea bag.

The program included a phone call consultation which was scheduled for fifteen minutes. The consultant asked the same qualifying questions that I filled out online when placing the order. These included my weight, age, activity level, etc. This program is not for the underweight, is not approved by the FDA and is not a medical treatment of any kind and Prolon wanted to record my acknowledgment of that fact. The consultant asked my goal for the program and I told her I was looking to lower my body fat percentage as well as treating the experience as an experiment. I mentioned I do the Wim Hof breathing, yoga and cold showers every morning and surprisingly she knew what it was and recommended I pause the cold showers for the duration of the fast. I mentioned I’ve been doing a callisthenics HIIT training every second day which she also recommended I hold off on. I also mentioned I drink two cups of coffee a day and she recommended I stick to one if I can. She asked if I had any questions and I didn’t. The entire conversation took about ten minutes. I still did the cold showers.

Day 1–161.8 lbs

I did a HIIT training for fourteen minutes. I wanted to give my body its best shot, and the HIIT training would burn fat for up to 48 hours.

  • I needed two coffees as I woke up with our toddler at 430 AM.
  • The breakfast was a nut-based breakfast bar called the L-Bar. The L-Bar was dense and sweet. It was almost too sweet for me which forced me to take small bites over time. The bar is sweetened with honey so although the diet is plant-based hardcore vegans may not agree with the honey thing.
  • I had one the teas that were included and was also caffeinated.
  • Lunch was a tomato soup which was delicious! It came with kale crackers that were thick and hearty. This blew me away. I felt as if I was eating at an Italian bistro (if Italian bistros served soup in the pot in which it was prepared). There was also a small package of olives that were a part of lunch, also delicious.
  • There was an afternoon snack that was another L-Bar. It was a lot of food for a fast. I also had another tea.
  • Dinner was a hearty minestrone and a small but dense chocolate bar. They both were delicious especially the bar!

The first day felt like I was preparing for the weak. It was filling and very tasty!

Day 2–158.5 lbs (-3.3 lbs)

I woke up with the worst headache. I overdid the caffeine yesterday and my body is out of balance. The entire day I played catch up and had to rest for a few hours. I thought about quitting but I didn’t want to break the promise to myself.

Today and the rest of the fasting days were to include what ProLon calls an L-Drink. It’s a bottle of concentrated liquid along with a large water bottle was provided. The instructions say to only use the amount of concentrate associated with my weight, about half fo me, and to dilute it with water. The mixture was to be consumed throughout the day. A tea bag that was also provided could be added for extra flavour which I did, using a hibiscus tea. The drink was mildly fruity.

  • Breakfast was the L-Bar which I did with a coffee.
  • Lunch was a mushroom soup I didn’t care for and olives. It was a pretty light meal.
  • Snack was just olives.
  • Dinner was a quinoa soup which was decent and another chocolate bar.

Day 3–156.4 (-5.4 lbs)

I woke up feeling great all day. The tomato soup with kale crackers was filling and satiated me in the afternoon. There was only a minestrone for dinner with no dessert bar and I was feeling a little hungry when going to bed. No chocolate bar makes Rob a sad cowboy.

Day 4–155.9 lbs (-5.9 lbs)

Woke up feeling good again but hungry. This was definitely the most challenging day. Had the L-Bar for breakfast, vegetable soup and olives for lunch, more olives for the snack and the quinoa for dinner and the chocolate bar!

My stomach was growling after dinner.

Day 5–154.5 lbs (-7.3 lbs)

Woke up pretty hungry and dove into the L-Bar. Did a little fist-pump to seeing that the lunch was the tomato soup and kale crackers. There was no afternoon snack and only minestrone for dinner.

I did my Wim Hof breathing exercises and pushups as I do every second day and felt just as strong as I am normally.

Day 6–155.1 lbs (-6.9 lbs)

It’s hard not to gorge myself in an epic binge but the instructions suggest to take it slow by starting with liquids then moving on to light meals. I took it slow but snacked all day. I felt great and was able to go back to my regular diet.

The Following Week

I continued to eat as clean as I could post fast avoiding processed sugars and limiting things like bread. My weight went back up to about 157 lbs and I’ve been the same for a while now. My strength was still there so was my energy. My body fat percentage came in at 15% down from 18.9% a few weeks before the fast! I have a better relationship with hunger now and I try to stick to a 12–14 hour daily fast that is to say that I mentally note the time when I’ve finished dinner or had a substantial snack and I avoid “breaking my fast” AKA breakfast until 12–14 hours later.


Let’s take a look at their claims. I took these from ProLon’s website:


ProLon helps promote natural multi-system regeneration, including effects on a wide range of markers that contribute to aging, such as cholesterol, inflammation, and fasting blood glucose.

There’s not much I can test here without a lab. I already pester my doctor enough with my bloodwork related to my diet experiments.


ProLon is clinically proven to help people lose an average of 5 lbs. of fat and 1.2 inches of waist circumference, while preserving lean body mass (muscle and bone).* *Science Translational Medicine — February 2017

I’ve lost 7.3 lbs in five days and I’m not a big guy. I started at 161 lbs. I don’t see or feel any muscle loss and when my first callisthenics workout easily, maybe even easier than before. This may be due to the fact that I’m lifting a lighter, leaner body. Either I was pleasantly surprised.


ProLon provides the body with healthy, plant-based ingredients that provide the body with optimal nourishment including essential vitamins and amino acids.

I think this is true but I’m not a fan of supplements at all so I prefer to get all my nutrients from whole foods. This is for a fast so I don’t think it’s a big deal.


ProLon was created in collaboration with some of the world’s best food scientists and chefs to provide delicious food that incorporates the science of FMDs™.

The food itself blew me away and I don’t even like soup. When I saw on the packaging that everything was from Italy I wasn’t surprised! Viva Italia!


ProLon meals come in 5 grab-and-go boxes (one for each day) that include plant-based energy bars, soups, a variety of snacks, drinks, and supplements.

It was very convenient. Every item was in high-quality packaging that was very clearly labelled.


ProLon uses healthy, plant-based ingredients including fresh olives, vegetables, fruit, nuts, seeds, dark chocolate and herbal teas, and does not contain any additives or chemicals.

It sure tasted like it!


I believe that all of the claims ProLon make, that I could measure, are true. It was challenging at times but much easier than a water only fast. If you want to try a fast and never have before ProLon might be a good way to try it out. Of course, I’d talk to a doctor first to make sure it’ll be safe.

I’m in Canada and ProLon doesn’t ship here so I had to have it shipped to family in the US who then shipped it to me so after that cost it was upwards of $300 (and in writing this right now I just realized I haven’t paid my brother in law back. Sorry Jon! Email transfer coming forthwith!). Although I do find this high I do recognize that it comes with all the food and supplements for five days not to mention the tremendous R&D that has gone into it. ProLon tries to make this a monthly subscription which I feel may be out of reach for many people. Perhaps ProLon can develop a less expensive version? Just a thought.

I was never overly hungry the entire time so the fast was missing that feeling which for most is probably a good thing. The only temptation I had was watching my wife eat our favourite foods and a few times during the week I would bite blueberries or strawberries into small chunks to give to our daughter.

Would I do it again?

I may consider it again in but there was something missing for me. This wasn’t a true fast. I wasn’t struggling as much as I have in my water (and coffee) only fasts and I liked the purity of the cleanse.

I kept the L-Drink remainder which I could use for another round and given that all the ingredients are provided in the packs I’m confident I could replace most of the food so technically I could mimic the mimicking diet once.

What Would I Improve?

  • The L-Bar was difficult to eat it was so sweet. If the science says we need the honey then maybe spread it out in other places. If it’s only there for taste I would rather less sweet and more nuts.
  • Replace honey with maple syrup or something else.
  • Optimize packaging to be more environmentally friendly.
  • Make it less expensive.
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