Fasting Kit Comparison 2026

BurnBox vs Prolon: Which Fasting Kit Actually Works Better?

Three days of near-zero-calorie fasting support vs five days of fasting-mimicking meals. We compared the protocols, convenience, price, and overall experience.

See Why BurnBox Wins Compare the Protocols

BurnBox

3 DAYS

ElectrolyteFiberBroth

Near-zero-calorie fasting support

Prolon

5 DAYS

Small plant-based meal boxes with soup, olives, a nut bar and tea

SoupBarOlivesTea

Fasting-mimicking diet

Fasting for days at a time used to be something monks did, or something you read about on biohacker forums. Now it's common among regular people as well, and two products are trying to make it easier. The BurnBox protocol guides you through a 3-day fasting period, while the Prolon protocol spans five days of eating small plant-based meals.

The decision to pick between the two brands majorly depends on whether you want a shorter fast that goes deeper (with a bit of help along the way) or a longer one. Let's cover both products in detail below to help you make an informed decision.

How they work

What a Fasting Kit Actually Does

A fasting kit doesn't burn fat for you. It only makes the fast bearable enough that you actually finish it. After about a day without calories from food, your body runs out of stored sugar and starts using fat instead. That produces ketones, which feed your brain and take some of the edge off your hunger.

Many people don't know how doable fasting for a long stretch is if there's a plan behind it. One study followed 1,422 people through supervised fasts lasting 4 to 21 days, all on 200 to 250 calories a day. 93.2% of them said they felt no hunger at all, and fewer than 1% had any bad reaction. That structure is what both of these kits are really selling through different approaches.

1,422

people in the supervised fasting study

93.2%

reported no hunger at all

4–21

days of fast length studied

<1%

had any adverse reaction

What Happens When Food Stops Coming In?

Stage 01
0–12 Hours
Using recent food + stored glucose
Food
Stage 02
12–24 Hours
Glycogen stores decline
Glucose
Stage 03
24+ Hours
Fat use and ketone production increase
Fat → Ketones

Timing varies between individuals.

The line-up

Meet the Two Contenders

Recommended

BurnBox

BurnBox is a 3-day fasting kit. It comes in three small drinks for you to replace food across the day: an electrolyte booster, a fiber shake, and a bone broth. Each one is only 15 to 30 calories, so your body is still fasting. The drinks are just to help deal with hindrances that usually make people quit halfway through. You start with a short quiz on the BurnBox site, and the kit arrives with instructions for before, during, and after the fast.

3-Day Protocol
Under 100 Calories/Day
3 Daily Tools

Explore BurnBox

Prolon

Prolon is a 5-day plan with food that's designed to trick your body into thinking it's fasting. Each day has its own box, with soup, nut bars, olives, kale crackers, tea, and a glycerol drink. Day 1 gives you around 1,100 calories, then days 2 through 5 drop down to 700 or 800.

5-Day Protocol
700–1,100 Calories/Day
Plant-Based Meals

Snapshot

At a Glance

Duration

BurnBox

3 days

Prolon

5 days

Daily Calories

BurnBox

Under 100

Prolon

~700–1,100

Format

BurnBox

Drinks

Prolon

Meals

Main Philosophy

BurnBox

Support a near-zero-calorie fast

Prolon

Mimic fasting while eating

Inside the kit

Inside BurnBox: Three Days, Three Tools

BurnBox offers three drinks, each formulated to fix one specific reason people give up on a fast.

01 / Electrolyte Booster

Minerals you stop eating

Electrolyte Booster: This is a 15-calorie packet you mix into 16 ounces of water. It gives sodium, potassium, magnesium, calcium, phosphorus, and chloride. When you stop eating, you also stop getting minerals, and a lot of the headaches, cramps, and fatigue people blame on hunger are actually just electrolyte imbalances.

15 CAL

NaKMgCa

Electrolytes for the fasting window

02 / Fiber Shake

Fullness without calories

Fiber Shake: This is a 30-calorie shake made mostly from psyllium husk and flaxseed powder. Psyllium soaks up water and swells in your stomach, so it feels fuller than it really is. In a double-blind study, people taking psyllium reported 13% less hunger and ate 17% less than the group on a placebo. This keeps your stomach full without giving your body enough calories to break the fast.

Dry psyllium

Expanded in stomach

30 CAL

13% less hunger
17% less food consumed

Reported in the study discussed above

03 / Bone Broth

The one moment that feels like a meal

Bone Broth (natural): This is a warm 30-calorie and 3 grams of protein drink made from chicken bone broth mixed with MCT oil powder. MCTs turn into ketones easily, and the broth also serves as the one moment in a fasting day that actually feels like you're having a meal.

30 CAL

3 G PROTEIN

Served warm

1 Fasting Day

Electrolytes
Fiber
Bone Broth

<100 CALORIES

Total daily support during the BurnBox protocol

When you add all three drinks together for a full day, you're still under 100 calories. That's why the BurnBox protocol helps you get into deep fasting mode faster than a fasting mimicking diet ever could. The brand says most users lose 4 to 6 pounds per fast, which is realistic for three days.

Brand claim: the 4–6 lb figure is a brand-reported claim. Individual results vary and some loss may be water weight.

Inside the kit

Inside Prolon: Five Days of Food That Mimics Fasting

Prolon basically says that you can get a lot of what fasting does for your body, without fully giving up food. There are five boxes, one for each day. Every day's box has everything you'll eat that day, and you cannot swap what's in one day's box for another because the order keeps your body in fasting mode throughout the protocol. You also get the L-Drink, which is a fruit-flavored glycerol mix made specifically to protect your muscles on days 2 through 5.

The issue with the Prolon protocol is time and how strict it all is. Five days is a lot to carve out of a normal week, and because you're still eating something, your body stays closer to normal than it would on a near-zero-calorie fast. That's good if you want a soft way into fasting, but it's a limit if you want something deeper.

Soup
Nut bar
Olives
Tea
L-Drink
Kale crackers

DAY 1
~1,100 calories
DAY 2
~700–800 calories
DAY 3
~700–800 calories
DAY 4
~700–800 calories
DAY 5
~700–800 calories

The biggest difference

Fasting vs Fasting-Mimicking

BurnBox

You mostly stop eating.

The kit supports the fasting experience with low-calorie drinks.

Empty plate + three small drinks

Prolon

You keep eating.

Calories are reduced enough to mimic some aspects of fasting.

Small plate with soup, bar, olives, and tea

Price & convenience

Prolon vs BurnBox on Price and Convenience

Even with just one kit, BurnBox is already cheaper per program, though the gap per day isn't huge since Prolon runs for five days while BurnBox runs for three. The difference is even clearer when you compare the bundles. Prolon's own trials used three cycles, so testing it the way they did runs over $500. A full year of BurnBox, done once a quarter, costs less than half that.

The two products offer different things in terms of convenience. BurnBox is lighter: just three packets, some water, and you're done. Prolon doesn't ask you to fight your willpower over eating, because you're still doing it, and for some people that makes five easier days beat three harder ones.

What Does Repeating the Protocol Look Like?

BurnBox — once per quarter

4 fasting cycles/year

Prolon

3 cycles used in Prolon's own trials

$500+

based on pricing discussed in this article

Prices can change. Confirm current pricing before purchase.

Check BurnBox Pricing

BurnBox

Pack: 3 drink packets · water
Time commitment: 3 days
Food preparation: Minimal

Prolon

Pack: 5 daily food boxes · multiple food items · drinks
Time commitment: 5 days
Food preparation: Structured daily routine

Side Effects and Who Should Sit This Out

Any multi-day fast, real or mimicked, can cause headaches, fatigue, dizziness, irritability, and constipation. These side effects are more pronounced the first time you try it. BurnBox's electrolytes and fiber are built to deal with exactly this, but no packet makes the symptoms disappear completely.

Neither program is meant for pregnant or breastfeeding women, anyone under 18, anyone with a history of disordered eating, or people with type 1 diabetes. If you take any medication, particularly for blood sugar or blood pressure, talk to your doctor before fasting in any form.

Balance sheet

Pros and Cons

BurnBox

Pros

Shorter 3-day protocol
Under 100 calories per fasting day
Electrolyte support
Fiber for satiety
Warm broth option
Minimal preparation
Easier to fit into a busy schedule
Lower long-term cost based on pricing discussed

Cons

More demanding because very little food is consumed
First fast may be uncomfortable
Requires committing to a true fasting-style experience

Prolon

Pros

You continue eating throughout the protocol
Structured five-day meal plan
May feel easier for fasting beginners
Established fasting-mimicking approach
Everything is portioned in advance

Cons

Five-day commitment
More expensive
More rigid daily meal structure
Higher calorie intake means it is further from a traditional fast

Our verdict

BurnBox vs Prolon: The Verdict

Prolon deserves credit for helping bring fasting-mimicking diets into the mainstream. If your priority is easing into the concept of fasting while still eating throughout the process, Prolon can be a reasonable option.

That said, when you compare the two side by side, BurnBox is the stronger choice for most people looking for a practical, effective, and sustainable fasting solution.

Here's why

01 — It delivers the benefits in less time.
BurnBox requires just three days instead of five. That may not sound like much on paper, but cutting the commitment by 40% makes it dramatically easier to fit into real life, whether you have work, family obligations, travel plans, or a busy schedule.
02 — It stays true to what fasting is supposed to be.
Rather than relying on specially designed meals to mimic fasting, BurnBox supports a near-zero-calorie fasting experience. For people seeking a more authentic fasting protocol, it offers a closer match to the real thing while helping make the process more manageable.
03 — It is significantly more cost-effective.
The reality is that fasting is not a one-time event. Most people see the best results when they repeat the process periodically. BurnBox's lower price point makes that far more realistic, allowing users to maintain a long-term fasting routine without spending hundreds of dollars every time.
04 — It's easier to stick with.
The best fasting program is not necessarily the one with the most research papers or the longest history - it's the one you'll actually complete and repeat. BurnBox lowers the barriers that often stop people from fasting: time, complexity, and cost.

Ultimately, both products can help people explore the benefits of fasting. But if your goal is to get a genuine fasting experience, spend less money, and minimize disruption to your life, BurnBox offers the better overall value.

Whichever option you choose, go in with realistic expectations. The first fast is usually the toughest; some water weight will naturally return afterward, and neither product is a substitute for healthy daily habits. Think of fasting as a tool that supports a healthy lifestyle - not a shortcut that replaces one. For most people, BurnBox is simply the more practical tool to keep using over the long run.

A woman in a bright minimal kitchen drinking a fasting beverage from a glass, with a small sachet on the counter — Fasting that still fits into normal life