Best Seller ProLon® Nutrition Bar pack with coconut macadamia, chocolate chip, and nuts honey flavors and assorted nuts and chocolate pieces

SKU FB111617EU · Fasting Mimicking Diet

ProLon® Nutrition Bar - 12 Pack

ProLon® Fasting Bar is an intermittent fasting bar that can help you fast for longer. (12 per pack)

Nutritional Fact Information

ProLon Nutrition Bar Nutritional Fact

Variety Pack - 3 Flavors £39.00

Nuts & Honey £39.00

Coconut Macadamia £39.00

Chocolate Chips £39.00

Select one or more variants

Ships from Lonso Milan facility · 72h after order confirmation · free cold-chain shipping on orders over €1,500.

Engineered to keep the fast

Only 3 g protein, 4 g net carbs, no added sugar. Insulin response is minimal — patients stay in the metabolic window.

MCT-driven ketones

MCT-rich fat profile supports endogenous ketone production. Ketones blunt the hunger signal at the source.

Pocket-sized assist

Individually wrapped, 38 g — designed for the moments adherence usually breaks.

How it fits the protocol

Inside the fasting window. When adherence breaks.

16:8 patients

One bar at hour 6–8 of the fasting window — the moment patients usually break. Lets them push to 16h consistently without willpower failure.

Hesitant fasters

For new patients afraid of hunger. Two weeks of supervised 14:10 with one bar in the window builds the confidence to attempt the 5-day FMD next.

Not during 5-day FMD

The Fasting Bar is NOT included in the 5-day FMD protocol — that kit's macros are precisely calibrated. Save the Fasting Bar for daily IF days between cycles.

What's in the bar

38 g, 150 kcal, fat-forward —
a macroshape that doesn't break the fast.

The quality and rate of our biological aging are the main determinants of a long and healthy life. Nutrition bar's strength lies in its unique combination of four natural ingredients with energising and antioxidant functions.

PER 2 CAPS

11 g

DHA · Algal Oil

Medium-chain triglycerides

MCTs convert directly to ketones in the liver without an insulin response, which is why they sustain a fast rather than break it. Cocoa butter rounds the texture without adding sugar.

Ketone fuel

PER 2 CAPS

~9 g

Almond + walnut

Whole, skin-on

Whole tree nuts provide a monounsaturated fat profile alongside vitamin E and a small dose of polyphenols. Texture comes from the nuts, not from emulsifiers.

Heart · LDL

PER 2 CAPS

5 g

Inulin + fibre

Chicory root + oat bran

Soluble fibre slows what little gastric emptying there is, smooths blood-glucose, and feeds the post-FMD microbiome. Same prebiotic family used in L-Biome.

Prebiotic

PER 2 CAPS

3 g

3 g plant protein

Pea + almond protein

Intentionally capped at 3 g — high enough to round the texture, low enough to keep the IGF-1 / mTOR pathways quiet. This is what distinguishes a fasting bar from a snack bar.

IGF-1 quiet

The fast, extended

Ketones up.
Hunger flatlined.The fast keeps going.

In a typical 16-hour time-restricted window, hour 8 is the wall. Patients break the fast not because of physiology but because of psychology. A Fasting Bar at the wall keeps both rising — ketones higher than a no-bar window, hunger blunted.

Glucose

Drops normally — the MCT-led macro doesn't spike insulin

Ketones with bar

Higher trajectory · MCTs convert directly to βHB

Ketones no bar

Patients often quit at hour 8 — no fuel to extend

Biological Age Score · Nature Aging, 2024

Three cycles. 2.5 years younger, on the data.

In the Mishra et al. 2024 trial (n=144, RCT), patients completing three consecutive Prolon FMD cycles reduced their Levine PhenoAge by an average of 2.5 years versus controls.

Read the Trial →

3 yrs

Biological Age Δ

−1.30 pp

HBA1C (12 wk)

−7.4%

Trunk Fat

96%

1st-Cycle Completion

FAQs

What is the Fasting Bar and how do I use it?

The Prolon Fasting Bar is an intermittent fasting bar that can help curb your hunger without breaking your fast, so you can fast for longer. It has been clinically shown to keep your body in a fasting state even after eating. You can eat it in the morning after your overnight fast to help curb your hunger and extend your fast until your next meal. A clinical trial showed that eating a Fasting Bar after an overnight fast has a similar impact on ketones and a nearly identical impact on blood glucose as drinking water.*

* Benefits seen in a randomized, controlled study in 105 adults after a 15-hour overnight fast comparing the glucose and ketone results every hour for 4 hours in the Fast Bar group, breakfast group and water-fast group. Data on file.

When and how often should I eat Fasting Bars?

You can eat a Fasting Bar once a day, as part of a healthy, balanced diet including regular meals during the day.

You can eat a bar in the morning after your overnight fast or as a healthy snack anytime during the day, in addition to meals, to help curb your hunger.

The impact and safety of consuming more than one Fasting Bar per day hasn’t been studied, and we recommend that you eat only one Fasting Bar in the morning or evening, along with a healthy, balanced diet for your other meals.

Fasting Bars are great for supporting time restricted eating and other short fasts. If you seek the benefits of prolonged periodic fasting, our 5-Day Prolon Fasting Mimicking Diet (FMD) has been clinically tested to provide the benefits of prolonged fasting and support overall metabolic health when used in multiple consecutive cycles.

Tell me about the science behind the Fasting Bar.

The Fasting Bar was designed with the same nutrition technology as the Prolon Fasting Mimicking Diet®. Our technology is the result of over 25 years of preclinical and clinical testing with over 36 million U.S. dollars in research and development funding from the National Institutes of Health and the United Kingdom Union.

Our dedicated Fasting Bar study tested the effects of eating a Fasting Bar at breakfast time (after a 15-hour overnight fast), compared to either skipping breakfast or eating a standardized breakfast bar. The study looked at blood glucose and ketone levels over the four-hour period after breakfast time and showed that blood glucose levels in patients eating Fasting Bar were nearly identical to blood glucose levels in patients who skipped breakfast.

Ketone levels over the four hours were also very similar in both groups. These results showed that eating a Fasting Bar doesn’t interfere with key physiological markers of fasting. The study also showed that Fasting Bar gave people a feeling of being fuller and curbed the desire to eat for up to 3 hours after consumption. In other words, you can eat a Fasting Bar to help make fasting easier and more pleasant, and maintain similar ketone and blood glucose levels as a water-only fast.

How can a Fasting Bar support fasting if it contains calories?

Scientists used to think that calorie balance (i.e.: calories consumed minus calories burned) was the most important factor in weight loss. But scientists now widely accept that not all calories are the same. Factors such as macronutrient ratios, total amounts, how the nutrients are digested and absorbed, and molecular composition all have an impact on how the body processes food.

The Fasting Mimicking Diet (FMD) and Fasting Bar have been carefully engineered, extensively researched, and clinically tested to allow for the consumption of nutrients and calories but still keep cells in a fasting state. Our special patented formula effectively hides from the body’s nutrient sensors, preventing them from sending the hormone signal that typically is sent after eating. The cells respond to the decrease in this hormone signal by entering a fasting state.

Is there a difference between Fast Bar and the L-Bar in Prolon FMD?

The Fasting Bar was designed with the same technology as Prolon’s L-Bars, but there are slight differences in size, calorie count and overall sugar content. Due to the carefully formulated macro and micro-nutrient ratios of the individual bars, they’re not intended to be interchangeable and should only be used as directed.

Complete the Protocol