Fast Bar Review

About Fast Bar

L-Nutra is a nutri-technology brand dedicated to creating innovative products to support healthy aging and longevity. Their flagship product, Fast Bar, is a plant-based, gluten-free, and non-GMO nutrition bar designed to support intermittent fasting. The company is committed to using science-based research to create high-quality, nutrient-dense products that promote overall health and wellness.

Fast Bar comes in three delicious flavors – Nuts & Honey, Cocoa Nuts, and Chocolate Chip – and is perfect for those new to fasting or looking for a convenient and healthy snack to support their fasting routine.

How Does Fast Bar Work?

People who practice intermittent fasting can use Fast Bar as a nutritional support tool. Intermittent fasting involves alternating periods of eating with fasting, during which the body uses stored energy from fat cells (1), which can promote weight loss and other health benefits. Fast Bar is specifically designed to support this dietary pattern.

The ingredients in Fast Bar, such as macadamia nuts, almonds, pecans, flaxseed, honey, cocoa butter, and rosemary extracts, are selected to provide essential nutrients that can help keep you feeling full during your fasting period. The bar is also packed with healthy fats, fiber, and protein, which can help reduce hunger and cravings (2), making it easier to stick to your fasting routine.

Fast Bar also helps support your metabolism and promote overall health and wellness. However, it’s important to note that Fast Bar is not a meal replacement, and it’s best to continue to consume a healthy and balanced diet during your eating periods.


  • Convenient: Fast Bar is a convenient option for people who are practicing intermittent fasting and need a healthy and portable snack to support their fasting routine.
  • Nutritious: Fast Bar is packed with healthy fats, fiber, and protein, which can help keep you satiated during fasting while providing essential nutrients.
  • Delicious: Fast Bar comes in three delicious flavors – Nuts & Honey, Cocoa Nuts, and Chocolate Chip – making it a tasty option for people looking for a healthy snack.
  • Science-backed: The ingredients in Fast Bar are carefully selected to support fasting and promote overall health and wellness.


  • Price: Fast Bar can be more expensive than other snacks, which may not be ideal for people on a budget.
  • Caloric Content: While Fast Bar is designed to be a low-calorie option, it still contains calories, which could break a fast if consumed outside of the fasting period.
  • Allergens: Fast Bar contains tree nuts, honey, and coconut, which may not be suitable for people with allergies or dietary restrictions.

It’s important to note that the pros and cons of Fast Bar may vary depending on individual needs and circumstances. It’s always best to consult with a healthcare professional before adding any new supplements or products to your diet.


Fast Bar

Fast Bar is made with a carefully selected blend of whole-food ingredients designed to support intermittent fasting. The ingredients of Fast Bar depend on the flavor, but here are the ingredients:

  • Almonds and Pecans: These nuts provide a source of healthy fats, protein, and fiber, as well as various vitamins and minerals.
  • Macadamia Nuts: A source of monounsaturated fats, fiber, and protein, as well as various vitamins and minerals.
  • Honey: A natural sweetener that adds flavor to the bars.
  • Inulin Fiber: Another prebiotic fiber that helps to improve the texture of the bars.
  • Flaxseed: A rich source of omega-3 fatty acids, lignans, and fiber, which can help to improve the texture of the bars and provide additional nutrition.
  • Cocoa Butter and Chocolate: Provide a rich and chocolatey flavor to the bars.
  • Natural Flavors: Derived from natural sources to enhance the taste of the bars.

5 Health Benefits of Fast Bar

1. Promotes weight loss

Macadamia nuts may aid in weight loss by reducing hunger and promoting fullness due to their protein and fiber content.

Macadamia nuts are also rich in monounsaturated fats, including palmitoleic acid, an omega-7 fat that could help prevent unwanted weight gain. Research on mice suggests that a high-fat diet with macadamia oil can lead to significantly smaller fat cells (3).

Almonds are rich in protein and fiber, which are known to increase feelings of fullness and prevent overeating. Research shows that consuming almonds significantly reduces hunger and the desire to eat (4). The satiating properties of almonds, including pure almond butter, make them a great addition to an effective weight-loss diet.

Furthermore, almonds and other nuts are difficult to digest, with the body not absorbing about 6% of their calories. Studies suggest that eating nuts may also boost metabolism slightly.

Almonds are the only nut that showed a small but significant reduction in body weight and fat mass (5), as supported by a review of 64 clinical trials and 14 meta-analyses. Despite their high-calorie content, almonds can still be a weight-loss-friendly food when eaten in moderation.

Inulin, a type of soluble fiber, dissolves in water and forms a gel-like substance in the stomach also increases fullness, slows digestion, and reduces cholesterol absorption as it passes through the digestive tract.

One can also consider coconut flour a rich source of both fiber and protein, with approximately 600 g of total dietary fiber per kilogram, consisting of 560 g of insoluble fiber and 40 g of soluble fiber per kilogram.

2. Provides healthy fats and improves heart health

Pecans are high in monounsaturated fatty acids (6), which may benefit heart health. Pecans may help improve cholesterol levels in both people with normal cholesterol levels and those with coronary artery disease.  

Macadamia nuts are also associated with a lower risk of heart disease due to their high monounsaturated fat content. Consuming macadamia nuts daily can reduce markers of inflammation (7), which are a risk factor for heart disease.

Eating flaxseed may also help lower cholesterol levels. A study on people with high blood pressure found that consuming the same amount of flaxseed daily led to significant reductions in BMI, total cholesterol, and blood pressure (8).

The fiber in flaxseed may cause these effects by binding to bile salts before the body excretes them. This, in turn, prompts the liver to draw cholesterol from the blood to replenish these bile salts, reducing cholesterol levels.

3. Assists with blood sugar control

Studies indicate that macadamia nuts can protect against metabolic syndrome and type 2 diabetes by reducing fasting blood sugar levels and improving long-term blood sugar control (9). Diets rich in monounsaturated fats, such as those found in macadamia nuts, may also help lower risk factors for metabolic syndrome, particularly in people with type 2 diabetes.

Pecans are also beneficial for blood sugar control due to their fiber content, which slows sugar absorption.

Almonds are rich in magnesium, a mineral that helps manage blood sugar and reduce insulin resistance (10).

Inulin, found in some foods, can slow digestion, stabilize blood sugar levels (11), and potentially aid in weight management.

4. Prevents oxidative stress

Macadamia nuts are a good source of antioxidants and flavonoids, which can help reduce inflammation and lower cholesterol levels. They also contain tocotrienols, a type of vitamin E with antioxidant properties that may help protect against cancer and brain diseases (12).

Almonds are also rich in antioxidants, particularly in the brown layer of their skin. Eating up to 60g of almonds per day can reduce markers of inflammation (13) in the body.

Rosemary contains high levels of antioxidants and anti-inflammatory compounds that can enhance the immune system and promote better blood circulation. Carnosic acid and rosmarinic acid, the antioxidants found in rosemary extract, also function as natural preservatives and extend the shelf life of meat by preventing the natural fat and oil from turning rancid.

5. Supports GUT and skeletal health

Inulin helps grow good bacteria, including Bifidobacteria and Lactobacilli, in the gut and stimulates digestion. These bacteria can help defend against unwanted pathogens, prevent infections, and stimulate the immune system. Inulin also adds bulk to stool and increases bowel movement frequency while slowing overall digestion to better absorb nutrients from food. Additionally, inulin helps improve calcium absorption (14), leading to a stronger skeletal system.

How to Take Fast Bar

Clinical studies have shown that Fast Bar can assist in controlling hunger during fasting periods and maintain the body in a fasting state even after being consumed. This can aid in extending the duration of fasting. Fast Bar is designed specifically for this purpose.

Consuming Fast Bar in the morning following an overnight fast can help control hunger and prolong the fasting period until the next meal. A study showed that a fasting-mimicking diet (FMD) energy bar did not interfere with the natural process of ketogenesis during overnight fasting, indicating that the bar could assist in intermittent fasting (15) or time-restricted eating.

Side Effects

While Fast Bar is generally considered safe, some individuals may experience side effects due to its ingredients.

Allergic reaction

Nuts are among the primary ingredients in Fast Bar, which can cause an allergic reaction in some people. Symptoms of a nut allergy may include itching, hives, swelling, difficulty breathing, and anaphylaxis, a potentially life-threatening condition.

High calories

It is important to remember that nuts also have relatively high calories. Eating multiple servings can increase your daily calorie intake, which could lead to weight gain if other adjustments to your diet or level of physical activity are not made. Therefore, it is advisable to moderate your intake, particularly if you are trying to lose weight.

Increased blood glucose level

Honey, another key ingredient, is a natural sweetener that may cause a spike in blood sugar levels, particularly in people with diabetes or prediabetes.

Increased blood pressure

Sea salt contains trace amounts of minerals such as iron, magnesium, and calcium. While these minerals can provide health benefits, consuming too much sodium can cause various health problems such as high blood pressure (16), osteoporosis, kidney stones, and more.

Does Fast Bar Really Work? Is It Worth Buying?

Based on its clinical effectiveness and the potential health benefits of its ingredients, Fast Bar could be a worthwhile investment for individuals looking to curb their hunger while maintaining a fasting state.

In a clinical trial, Fast Bar demonstrated its ability to curb hunger and sustain the body in a fasting state. The study, which was randomized and controlled, examined the glucose and ketone levels every hour for four hours in the Fast Bar group, breakfast group, and water-fast group after a 15-hour overnight fast. The results showed that consuming Fast Bar after an overnight fast had comparable effects on ketones and blood glucose to those drinking water (17).

However, as with any dietary supplement, it is important to consider individual health needs and consult a healthcare professional before adding it to your diet.

Fast Bar Reviews 2023: What Do Customers Think?

“As a health coach, I highly recommend fast bars to my clients when they are finding it challenging to hit their 16 hour fast. Fast bars are helping my clients stay with intermittent fasting protocols. I love them to have nutrition before I play tennis or workout and still be actually keeping my 16 hour fast. It’s a miracle for me personally and they taste like a nut bar.” – Sherri Lane

“Easy ordering process, quick shipping. I’d already tried and loved the nuts and honey fast bars, so I wanted to order the other flavors. These are so good and they do not raise my blood sugar AT ALL!” – Amy Munera

“I recently ordered a large quantity of fastbars because I’ve ordered before and really like them. The ingredients are excellent quality, the taste is much better than similar items on the market, and the amount of calories is just right. I use them when I do a several day fasting mimicking fast as well as for snacks in general. Thanks for an excellent product.” – Deborah

Where to Buy?

Fast Bar is available online through their official website at or other online retailers like Amazon. It may also be available in select health food stores and specialty retailers.


How can Fast Bar support fasting if it contains calories?

The creators of Fast Bar carefully engineered, extensively researched, and clinically tested the product to enable the consumption of nutrients and calories while keeping cells in a fasting state. Their patented formula evades the body’s nutrient sensors, which send a hormone signal after eating. As a result, the cells enter a fasting state due to the decrease in this hormone signal.

How often should I eat Fast Bar?

You should eat Fast Bar once a day, 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 Fast Bar per day haven’t been studied, and you should eat only one Fast Bar in the morning or evening, along with a healthy, balanced diet for your other meals.

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

Fast 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.


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  8. Toulabi T;Yarahmadi M;Goudarzi F;Ebrahimzadeh F;Momenizadeh A;Yarahmadi S; (n.d.). Effects of flaxseed on blood pressure, body mass index, and total cholesterol in hypertensive patients: A randomized clinical trial. Explore (New York, N.Y.). Retrieved March 27, 2023, from
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  • Marixie Manarang, MT, undergrad MD

    Marixie Manarang is licensed Medical Laboratory Scientist and an undergraduate of Doctor of Medicine (MD). For one year, she completed her internship training in a government hospital, primarily catering to retired veterans and their dependents. Through her preceptorships in medical school, she gained exposure to patients from various medical departments. Marixie’s passion for writing stems from her excellent medical background, being a mother, and a strong desire to assist the elderly and others in need. Education: Our Lady of Fatima University Doctor of Medicine (MD), Doctor of Medicine (2012-2015), Angeles University Foundation Doctor of Medicine (MD), Doctor of Medicine (2009-2011), Angeles University Foundation Bachelors, Medical Technology (2004-2009)






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