I Tried ProLon: The 5-Day Fast-Mimicking Diet That Helps Your Cells Self-Repair

ProLon's The Fasting Mimicking Diet (regularly priced $249) is like no other. Masterminded by Dr. Valter Longo, the five-day diet plan is designed to put you into a fasted state without having to forgo food. Unlike other diets, ProLon's program isn't too focused on weight loss (although that is a side effect for many). Instead, the aim is to promote cell-based self-repair and rejuvenation—a cellular clean-up if you like. The pre-packaged food, supplements and drink mixes are expertly put together to trick your body into a fasted state and to keep you surprisingly satiated.

Intermittent fasting, when done correctly, shows a host of benefits in animal models, from stress reduction to cellular repair and regeneration, to improved cognitive function and memory, and even reduced risk of disease. Preliminary research suggests similar benefits may extend to humans. 

Plant-based and surprisingly tasty, ProLon is supposed to be done in cycles of five days in three consecutive months. The biggest draw is that ProLon claims to help you lose visceral fat in the belly area, which can be a stubborn spot for some people (and can even lead to health issues); in clinical studies conducted by Longo and colleagues, individuals lost on average 5.7 pounds and 1.6 inches from their waist circumference after doing ProLon. The brand also emphasizes other health benefits—such as cellular cleanup and balancing your metabolism while giving your body a scientifically-developed combination of micro and macronutrients—as a reason to give it a try.

I gave The Fasting Mimicking Diet a try for five days and this is how it went. Would I do it again? Keep reading to find out.

The Fasting Mimicking Diet Day 1:

ProLon's The Fasting Mimicking Diet comes in a fairly small box. I'm worried—how are these small packets of food going to keep me going for almost a week?! Inside the box are five smaller boxes, each contains everything you need to eat and drink. There is also a handy schedule so you know what to consume and when, from the supplement and teas to the soups and bars.

The first day packs in the most calories (around 1100) which is less than I usually eat but still, it feels pretty easy. The morning starts with a lemon and spearmint tea, a pretty filling snack bar and an algal oil supplement. At lunch, I devour a tomato soup, seriously good kale crackers, olives with sea salt and an NR-3 supplement (a multivitamin and mineral). The afternoon consists of a spearmint tea and another snack bar. Then at dinner, I have minestrone soup, an L-Bar (a sticky chocolatey snack) and another multivitamin. I'm not too fussy about my food (I like plane meals) but I found it all quite tasty. The handy day planner helps keep me on track and there wasn’t too much time between eating or drinking.

The Fasting Mimicking Diet Day 2:

From days two to five, you have a citrus flavored L-Drink that you add to water in the ProLon bottle you receive (the amount you add is dependent on your body weight). It tastes good and is meant to stave off hunger between meals, but I'm still pretty hungry. I'm quite distracted at work and ended up getting a pretty terrible migraine in the evening and have to go to bed early. I’m guessing it was caffeine withdrawals? So if you drink a lot of coffee, I’d suggest reducing your intake in the run-up to starting The Fasting Mimicking Diet.

The Fasting Mimicking Diet Day 3:

My headache has subsided and I'm not as hungry as I was the previous day. It feels much easier, even though today there was no olives or chocolate bar to snack on. However, there is a good mix of soups to keep things interesting. Yesterday was mushroom followed by minestrone and quinoa, today is tomato soup again and plain minestrone for dinner. Having said that, I meet friends in the evening and they remark that I definitely didn’t seem my usual happy self!

The Fasting Mimicking Diet Day 4:

I'm definitely into the groove of things by day four. I felt less bloated and have much more energy than earlier in the week. Plus, I can see the light at the end of the tunnel. Today, I can also snack on not one, but two packs of olives—but then disaster strikes... This was the last day that included the little chocolate bar, but it's missing from the box! I don't think I've ever been so hangry than at that moment.

The Fasting Mimicking Diet Day 5:

Migraine aside, the five days were pretty easy! Day three and five were the lowest on food and lacking any sort of treats like the chocolate bar (have I mentioned that?!) or olives. But knowing I would soon be able to eat normally again, I managed to get through the last day. I definitely noticed I was less hungry on day five compared with at the beginning. In the pack you are given a Transition Meal Guide for day six: avocado on toast for breakfast, roasted vegetables for lunch and kale & carrot soup for dinner. Then, there is a suggested shopping list of foods to stock up on and incorporate into your daily meals moving forwards.

My Final Thoughts

All in all, ProLon's The Fasting Mimicking Diet is fairly straightforward and the five days didn’t feel too long. As I mentioned, afterwards, you’re meant to ease your way back into regular meals with plenty of healthy, nutrient-dense food but—full disclaimer—I went out for a curry! I lost about six pounds in a week, which I wasn’t expecting, as this detox is about longevity rather than weight loss. I’d say I put half of that weight back within a week. However, in the days afterwards, I definitely felt like I had more energy, my skin was clearer and the detox put me into a good habit of drinking more water, something I tend to forget to do. It also had me craving fresh fruit and vegetables and any foods that hadn’t seen a packet, and that’s not a bad thing! The Fasting Mimicking Diet is designed to be done three times during consecutive months each year to reap the longevity benefits and I wouldn’t be against doing it again but, for now, eating fresh foods and drinking more water will do me fine.