What I Learned from 13 Rounds of the ProLon Fast

Health has been on my mind lately.  I tend to get reflective around my birthday, which is in a few days.  When I was younger, if anyone would have told me that I would feel fitter at 58 than 38 or even 28, I would have thought they were crazy.  But it’s one of the reasons I’m so passionate about wellness.  Our daily lifestyle choices add up to big gains over time.

I’ve also been thinking about a recent conversation I had with Audrey Zona, who is an integrative health and nutrition coach.  Audrey shared the health benefits of a five-day fasting program called ProLon, developed by Dr. Valter Longo, professor and director of the Longevity Institute at the University of Southern California.

Dr. Longo has studied the lifestyles of thriving centurions and has found that periodically cutting out food for extended periods can improve a natural process called autophagy, which is the body’s way of clearing cell debris.

I did my first ProLon fast in 2019 and have completed it quite a few times since.  Here are some thoughts on that journey, along with what I learned and some tips should you choose to try it yourself.

What is ProLon?

It’s a five-day meal program that’s fast mimicking.  That means, the food combination was designed so the body’s cells believe they’re not being fed, shifting the body into fasting mode so you reap the benefits of a water fast while still eating a limited amount of food.  This allows for cellular repair and regeneration throughout the program – along with decreased inflammation and increased fat loss, especially visceral fat in the belly area.

The food is sent in a box that contains five pre-packaged meal kits for each day plus a 32 oz. bottle to sip fluids throughout the program.  Daily meals are a mix of breakfast nut bars, dried soup blends that are prepared by adding water and heating, olives, crackers, a few small dessert bars, and a handful of vitamin supplements.

There are also herbal teas and a glycerol-based drink, called L-drink, that supports the loss of fat and not muscle as well as the feeling of fullness.  All food is 100% plant-based, gluten-free, and non-GMO with no artificial additives.

A few extras are allowed per day, including a cup of black coffee plus decaf coffee and tea, one wedge of lemon added to water, 1 tsp of herbs for the soup, and plain sparkling water.  No artificial sweeteners are allowed.

During the five days, only the food within the box for that particular day is consumed, so there’s nothing additional to buy or prepare.  The food is low in carbs and protein and high in healthy fats.  The macro breakdown is approximately 40% carbs, 10% protein and 50% healthy fat.  While the program does not permit changing the order of the days or swapping food between days, you can eat what’s in the daily box in any order you choose.  A menu card is provided as a helpful guide and I find I only make small adjustments to their suggestions.

ProLon also has coaches on staff along with the option of joining daily Zoom calls hosted by nutritionists throughout the program for support.

When ProLon hit my radar screen in 2019, the focus on longevity was of interest.  I was still working in a corporate setting the first time I tried ProLon and had access to a microwave that I used for my midday meal.  The evening soup is prepared on the stovetop.  Breakfast and snacks are portable bars, as are the teas and L-drink.

Day 1 was the easiest, with 1100 calories of food including several bars.  Days 3 and 5 had the lowest calorie count, around 770 each day.  But something seemed to click after Day 3 once I was over the proverbial hump.  Not only was the end in sight, but I started to feel the results, including clear-headedness and weight loss. 

Why did I do it 13 times and counting?  Quite simply, because I feel amazing by the end of the five days.  Every single time.  Not only does it reset my physical body, but it gives me a mental break because I don’t have to think about meal preparation for five days – that frees up so much space.  I use that time to walk, journal and get extra sleep, which renews me mentally and spiritually.

Lessons Learned From My First ProLon Fast

As with anything in life, mindset is everything.  I set the intention that my first fasting experience would be one of exploration, connection and insight.  I thought of it as an investment in myself.

And it did feel like a wellness investment, even like a luxury, like a spa in a box or an in-home retreat.  ProLon is packaged in a sleek white box that contains a large water bottle and all the food needed for the fast in boxes numbered from 1-5, along with simple instructions and suggestions.  It just feels good, like giving yourself a gift.

The physical benefits were as expected – more energy, a feeling of lightness, slimmer waistline, looser clothes and a loss of six pounds.  I did have to work through a mild caffeine withdrawal headache the first few days and I did find myself craving fresh fruit and vegetables.

Looking back I can say the first time was definitely the hardest.  But it not because of any physical hardship.  It was more about getting over the mental hurdle of being on a fast – that feeling of “Can I do this? Can I make it to the end?”

I was most surprised at how often I thought about food throughout the day as part of my routine, not of hunger.  The impulse to go get a cup of coffee or eat an apple - every few hours reaching for something out of habit.  That mindfulness helped me understand the difference between true hunger (which I didn’t experience too often) and perceived hunger (when what I really needed was to drink water or take a break from whatever I was doing).

When I came to the end of my first fast, I knew I’d try it again – I felt that good.  And it was absolute euphoria having that first meal on Day 6 – cubed fresh fruit with homemade almond milk and a cup of coffee.  Amazing!

That first fast helped me create new habits.  I bought a few boxes of Fast Bars, which are the breakfast bars from the fast, and began having those for breakfast, extending my natural intermittent fasting periods.  My food portion sizes became smaller naturally.  I became more tuned into my body, now having the discernment to know when I was truly hungry or when I was reaching for food out of habit.

Lessons Learned From Subsequent Fasts

There’s something nice about giving yourself a pause from your routine from time to time.  Each fast gets easier to complete.  I’m always proud of myself at the end of the five days.  And I still enjoy getting a break from being in the kitchen.

Even though I stay within 5-10 pounds of my ideal weight, I have routinely lost 6-8 pounds during the ProLon fast, all around the mid-section.  This makes ProLon a great tool for me whenever I find my weight begin to trend up a bit.  It keeps me in a comfortable weight range.

Having been through the fast multiple times also allows me to enjoy the process, especially the clear-headedness which gives me a deep sense of energetic calm.  I love taking a break from my CrossFit and running routine and enjoy taking long walks instead.  I also sleep really well during the fasts.

My end of fast celebration is to go food shopping on the last day of the fast for the transition day, which is Day 6.  That’s when you can eat your normal diet again. But you need to be careful not to hit your body with too much food.  I find that I’m so in tune with my body, the last thing I want to do is overeat.  In fact, that has been a great by-product of repeatedly doing the fast – I no longer like the feeling in overindulging.  This is a huge mind shift and I credit the ProLon process for getting me there.

If you decide to try ProLon, here are some considerations and suggestions:

  • Take advantage of the free virtual ProLon coaching services or find a buddy to do it with – it’s much more fun in community.

  • Minimize your exercise during those five days – but do walk and stretch each day.

  • Get sufficient sleep.

  • If you drink caffeine, consider tapering off before starting the fast so you don’t get withdrawal headaches.  I find it helps to gradually switch to decaf a week before.

  • Keep a journal to capture your learnings – especially what trips you up when you’re not fasting and how you might address that moving forward.

  • Use the last day of the fast (Day 5) to plan for your transition.

  • On Day 6, enjoy that first sip of coffee or that first meal – it will taste unbelievably amazing.  You will feel nothing but gratitude for the food you’re about to enjoy.

Depending on your goals, you can complete this program safely once a month and then transition to whenever you feel you need it again.  Back in 2019, I did it for a few months in a row, then every other month before switching to a seasonal approach:  right after New Years, springtime, and early fall.  And I’m getting ready for round 14, which I’ll start the day after my birthday.

However you choose to do it, I hope you find ways that help you reset from time to time.  You deserve it!

Note:  Special ProLon offer for readers of The Athena Wellness blog, which can be used and shared repeatedly: 

The views contained in this blog are not medical advice.  Please consult your health professionals before considering a change in your health and wellness routines.