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Prolon Review – the 5-day Fasting-Mimicking Diet

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box of prolon

ProLon® is a 5-day dietary program designed to mimic the experience of fasting, but with food! Decades of research went into designing this plant-based fasting-micking-diet (FMD, and a kit comes with everything you need for 5 days.

I won’t get too much into the benefits of fasting here, but the results go far beyond weight loss. I highly recommend watching the documentary “The Science of Fasting“, available on Amazon Prime for information on the studies.

Ever since watching that and several other documentaries about fasting, I’ve been fascinated with the idea that sometimes our bodies need a break from feeding in order to do its job more efficiently. I love food – I literally talk about it for a living – and also know that the right food can be extremely healing. But it makes sense to me that if we are constantly digesting, other bodily functions might be put on the backburner.

I’ll be honest, I had this box sitting in my pantry for MONTHS before biting the bullet to try it. I had recently done the 5-day detox from Sakara and the idea of another 5-day restrictive plan wasn’t all that appealing to me.

But one Saturday I woke up late and by the time I was hungry I realized it was 1:30pm and I’d already basically been fasting, so I thought that day would be a good day to start!

Spoiler alert: I completed 4 full days of the 5. Keep reading to see my experience and results.

ProLon® Fast | Fasting Mimicking Diet

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prolon 5 day eating schedule

Note: The kit is fully vegetarian and primarily plant-based, the only ingredient that makes it not fully vegan is the honey in the breakfast bars. There are also cross-contamination warnings on some of the foods so be aware of this fi you have severe allergies.

Day 1

I started off strong, considering I hadn’t planned to start this day. But the time I started my eating window it was close to 2pm, so I had breakfast and lunch close together.

Breakfast was a nut butter bar and two algal oil vitamin pills. Algal oil is made from algae, and is one of the few vegan sources of EPA and DHA, which are Omega-3 fatty acids. (You can read more about the benefits of algal oil by clicking here.)

The bar (what they call the L-bar) actually wasn’t bad even though I kind of expected it to be. The consistency was chewy and tasted mostly like nuts, considering the first 3 ingredients are macadamias, pecans, and almonds.

Lunch consisted of tomato soup, 5 crackers, 8 olives and 4 NR-1 vitamins, which were essentially multi vitamins made from powdered vegetables.

prepared tomato soup, kale crackers and green olives from day 1 of prolon

The soups are dehydrated and remind me of those “space food” kits from when I was younger. You add a cup of water and heat it up on the stove or microwave – or I started to just boil water and then add it to a mug and mix well. I did not add any spices (you can add up to a teaspoon) and it tasted fine.

The afternoon snack was another nut bar and tea. I didn’t drink the tea every day as I prefer just water, but they have different flavors like lemon, hibiscus, or spearmint.

Dinner was supposed to be minestrone soup and you even get a chocolate bar for dessert. Its not super sweet but it is chocolate nonetheless.

Note I say “supposed to be” – I ended up getting an invite from friends to meet out and I failed the first day by having beer and pizza for dinner. This is what I get for starting the plan on a Saturday!

(In my defense, the last time I was invited out by this group was when I was doing the Sakara detox and I turned them down. Yolo.)

day 1 of food with prolon FMD laid out on table
Everything included on Day 1

Day 2

On the second day I almost gave up all together but I still had 4 days worth of fasting food so I decided to give it a shot. I also read more about the benefits of this plan which helped me stay on track.

You are allowed to drink one cup of black coffee a day, so I did this for the remainder of the experiment.

half a Prolon L-bar held in hand
About half of the breakfast L-bar

All of the days are fairly similar, though on day 2 the snack is replaced with a second serving of olives, and you don’t get crackers with your lunch. The soup for lunch today was a mushroom soup, which I actually really liked! I was bummed to find out that it was the only serving of mushroom soup during the plan.

The other change on day 2 is that’s when the L-Drink is introduced. On my meal program card it is listed at the bottom, so I thought it was supposed to be an after-dinner drink. However after reading the instructions I realized it was supposed to be something you were sipping on all day! Be aware of this if they don’t change the instruction card to be more clear.

The L-drink is a glycerol mixture you add with water (the amount you mix in is based on your weight). The main purpose of this drink is to provide glycogen to your muscles so that you don’t lose as much muscle mass while fasting.

Since I realized this is actually my Day 1 again, I don’t worry about drinking all of the L-drink before bed since my muscles weren’t actually starving yet.

The flavors for the glycerol drink alternate between orange and berry, and the flavor is really subtle. They have “natural flavors” which is not normally something I prefer, but this is a special circumstance.

Many people like to add one of the hibiscus tea bags to the L-drink for more flavor.

ProLon® Fast | Fasting Mimicking Diet

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Days 3-5

Day 3 and Day 5 are the most restrictive days. There are no olives, no snack and no dessert!

Somehow though Day 3 (or my actual day 2) was easy for me. If anything I was just bored, and got the occasional feeling of hunger but it wasn’t too bad.

I even waited as long as possible to have lunch, and then was busy with other things before I realized it was time for bed and I didn’t eat the dinner. So I did pretty well on the most restrictive day thus far!

One thing I start to notice is I’ve slept amazingly these last two nights. I had been dealing with insomnia and waking up for hours in the middle of the night for weeks on weeks, but this week I fell asleep quickly and soundly for 9-10 hours.

Day 4 is the same as Day 2 except with a vegetable soup for dinner.

day 4 of food from prolon FMD laid out on table

Day 5 is the same as Day 3, with another dose of algal oil.

Results and Summary of My Experience

5 boxes of prolon

On day 6 (or, my modified day 5) you are supposed to ease in to normal foods again. Don’t go crazy with all the things you were craving in the beginning – I made this mistake with the Sakara detox and it definitely didn’t go well. Since I was making up for my failed attempt at day 1, I had a fast bar and black coffee in the morning and fasted until dinner that day. So I technically had 5 days of the FMD since I went from dinner Saturday – dinner Thursday.

I’ve seen some people who lost zero weight and some people lose 10-15 pounds during these 5 days. I think it depends a lot on how much weight you have to lose (I do have weight to lose) and how well your body uses your fat storage for energy.

I lost 3.1 pounds from day 1 to the morning of day 6. (I technically gained 3 pounds after day 1 with my beer and pizza, so depending on how you look at it I lost 6 pounds from day 2 to day 6). I’m sure a big part of this is water weight (or what I like to call “food weight”) because I hardly had any food inside me. I know the main goal goes much beyond weight loss, and I do feel like my body had a bit of a reset and hopefully learned how to use fat as fuel more efficiently.

Even though I messed up on day 1, I’m proud of myself for sticking with it for the following 4.5 days. I slept better than I have in months, had some very productive hours and I wasn’t as hungry as I thought I would be.

More than anything, what I had to overcome was boredom – like many people, I structure my day around food and have a stocked pantry and fridge that was calling my name this week. It definitely brings to your attention to how often you eat simply to have something to do, or have a moment of happiness.

The ProLon food itself was actually good. Obviously not pizza, but better than I expected and much better than a water-only fast.

picture of dehydrated tomato soup mix from Prolon shown on spoon
Package of the tomato soup before adding water.

If you don’t like olives, mushrooms, and/or nuts you might have a harder time with this plan, but it’s still doable.

I didn’t do any major exercise, just a few minutes at a time on my rebounder trampoline to get the lymph juices flowing.

It’s recommended to not eat anything else outside of the program, including vitamins – but I did drink black coffee in the morning, and I took my probiotics on a few days because I was burping a lot. (This apparently is a side effect of high stomach acid, which can be exacerbated by fasting.)

My Top Tips

  • Drink lots of water throughout the day. I didn’t drink the teas in the afternoon but I think the main reason they include these is for the hydration, and if you don’t like the taste of plain water you can put one of these tea bags in your water bottle for a little extra flavor (either with the L-drink or even regular water).
  • Watch a fasting documentary or read about the benefits on the ProLon site before and during the diet to help stay motivated.
  • Look at your schedule and pick your start date accordingly. I found it easier to stick to when I didn’t have other social events or plans, but you may find it easier to follow if your schedule is packed.
  • Start your eating window as late as possible, if you can. I’m not much of a morning eater so this was easier for me to do, and I found it helpful to have a shorter window of time between meals.
  • Above all, listen to your body. Individual experiences vary and only you know what’s best for you. This may mean stopping early if you have to, exercising or not depending on your energy levels, etc. In general I wouldn’t recommend this plan for anyone who is triggered by or has a history with restrictive eating.
ProLon® Fast | Fasting Mimicking Diet

Get 15% off your kit with code TRIALANDEATER at checkout! Not applicable on subscriptions.

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Prolon instructions with 5 small boxes of food, one for each day of the fasting mimicking diet

Price and Discount

Normally one 5-day kit costs $250 but lately they’ve been discounting it to $199. If you use the link and code below, that would bring the price down to $169 for a one-time purchase or $160 per kit if you bought a 3-pack. *Note that this coupon code will not work on subscription orders.*

Remember to use discount code TRIALANDEATER to save on your Prolon kit!

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