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How Do Carb Blockers Work? (Are They Really Effective?)

Isaac Robertson
Published by Isaac Robertson | Co-Founder & Chief Editor
Fact checked by Donald Christman, BHSc FACT CHECKED
Last updated: March 22, 2023
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Today, many popular diets minimize the amount of carbs to reduce sugar in the body and promote overall wellness.

However, carbs are also associated with some of our favorite foods, making them tempting to resist.

That’s where carb blockers come in.

These supplements prevent many of the side effects that come with ingesting carbs, allowing you to enjoy your favorite meals without worry or indigestion.

We’ve spent hours delving into what medical research has to say about carb blockers and their effects. Read on to learn more.

Quick Summary

  • Carb blockers work by blocking the digestion of complex carbs, helping in weight loss and improving an individual's overall health.
  • Scientifically, it has been proven that carb blockers can help control blood sugar levels.
  • Some natural alternatives to carb blockers are limiting your carbs intake, adopting a ketogenic diet, or trying out the Paleo diet.

How Do Carb Blockers Work?

spilled capsules in a bottle

Carb blockers - also called starch blockers, are dietary supplements that prevent the digestion of complex carbs. By blocking carb digestion, carb blockers may aid with weight loss and improve overall health.

Carbohydrates can be classified into two groups: simple carbs and complex carbs.

Simple carbohydrates are small chains of sugar molecules found in foods such as milk, fruits, ice cream, and candy. These simple sugars are rapidly absorbed by the body and grant quick bursts of energy.

Starch blockers, unfortunately, do not block carbs of this type as they are quickly absorbed once ingested.

Complex carbohydrates, on the other hand, are made up of long chains of simple carbs. Complex carbs are slower to digest and typically found in whole grains, legumes, and starchy vegetables.

Compared to simple carbs, complex carbohydrates are composed of larger, more complex chains of sugar molecules. This complexity allows them to withstand instantly being absorbed by the body.

As a result, they must go through the digestive tract and be broken down by the digestive enzyme alpha-amylase.

Carb blockers prevent the body from producing this enzyme. As a result, the undigested starch passes through the body without contributing any calories, as it is not absorbed.

Lastly, carb blockers come in two types: 

  • white kidney bean extract made from white kidney beans and
  • alpha-glucosidase inhibitors (AGIs).

AGIs are a form of diabetic medication used in the treatment of type II diabetes.

Both of these blockers accomplish the same result. The only difference is that white bean extract inhibits amylase production in the mouth and the pancreas, while AGIs target alpha-glucosidase enzymes in the small intestines.

Are They Effective?

female medical person holding a bottle of capsules

Several studies suggest that carb blockers are quite effective - inhibiting up to 65% of carb digesting enzymes.

Carb blocker supplements work by blocking the body’s natural digestive enzymes.

That, however, creates the opposite effect in the pancreas, which reacts by producing more enzymes.

Over time, this process results in a portion of carbs that break down and become digested.

As a result, carb blockers only prevent a small portion of carbs from being blocked.

While this portion may seem small, it is significant in weight loss management as every calorie counts.

One study showcases this effect by examining a strong carb blocker in the digestion of carbs and weight loss.

The carb blocker was capable of inhibiting up to 97% of the enzymes but only prevented 7% of the carbs from being absorbed by the digestive system [1].

3 Main Benefits of Taking Carb Blockers

woman holding an apple with a measuring tape around it, man measuring his waist

Carb blockers offer a number of benefits, such as helping with weight loss, managing blood sugar, and increasing the body’s resistance to starches.

1. Weight Loss

Carb blocking supplements have shown to provide significant results with weight loss and fat management. That makes them an effective weight loss supplement on top of preventing carbohydrate absorption.

Most issues surrounding obesity and excessive body fat are due to an unhealthy obsession with diets rich in starch.

These supplements minimize the number of carbs absorbed into the body, reducing overall calories and managing body weight.

In addition to reducing carb absorption, a carb blocker also affects the hormones responsible for hunger and appetite control.

Carb blockers increase the concentration of satiety hormones while suppressing the hunger hormone ghrelin.

A reduced appetite further aids in reducing the amount of calories ingested in a day and can help lose a few extra pounds.

Scientists also support these claims. For example, one rat study found that rats ate significantly lesser food amounts when given carb blockers alongside their meals [2].

By inhibiting digestive enzymes, carb blocking supplements slow down the carb digestion process, helping people feel full for longer durations.

2. Blood Sugar Control

person using glucose level checker

Carb blockers have a significant impact on blood sugar levels.

As mentioned earlier, carbs are chains of sugar molecules that are easily absorbed into the body. Therefore, the more carbs get absorbed, the higher blood sugar levels rise.

By limiting the amount of carbs that get absorbed into the bloodstream, carb blockers also help normalize blood sugar levels.

Taking a carb blocker supplement like white kidney bean extract has led to improved blood sugar control by stabilizing blood sugar spikes - even after ingesting a large amount of carbs.

One study examining diabetic patients involved measuring the blood levels of patients after consuming carbs.

“Blood samples were taken before the intake of the rice and 30, 60, 90, and 120 minutes afterward. Blood sugar levels 30 minutes after eating the rice were significantly lower with the test product. Plasma insulin levels were [also] significantly lower compared to the control at 30 and 60 minutes after consuming the rice [3].”

- Marilyn L. Barrett, Pharmacognosy Researcher

That means that type II diabetes patients can indulge in starchy diets as much as they want without worrying about their blood sugar control.

While starch blockers assist in controlling blood sugars, they are just a temporary solution.

Sticking to a low-carb diet is the most effective long-term way to minimize carbohydrates in the body and regulate blood sugar levels.

3. Increasing Resistant Starch Levels

shirtless man holding his abs smiling

Resistant starches are a type of starches that are not digested and often find their way into the large intestine undigested.

They are fermented by gut bacteria and create short-chain fatty acids and important gases.

As higher starch levels have been associated with decreased body fat, healthier gut bacteria, and increased insulin sensitivity, carb blockers may also assist in carb digestion and wellness.

Side Effects

close up image of a person holding his stomachache

The most common gastrointestinal side effects when taking this dietary supplement include bloating, low blood sugar, stomach cramping, diarrhea, and gas.

These gastrointestinal side effects are a result of the rapid change in starch digestion and occur due to gut bacteria found in the large intestine.

Due to the increased amount of resistant starch, our bodies find it difficult at first to ferment all of it.

As a result, the digestion process releases gases, which can be uncomfortable for the gastrointestinal system.

To manage these effects, start with a small dose and work your way up as your body builds tolerance.

These side effects are short-lived and eventually clear out with time, as the body breaks them down, and the carbs pass out.

Additionally, carb blockers are not as strictly regulated as other supplements. So if you’re planning to use them as weight loss supplements, make sure the supplement manufacturers are reputable and can be trusted.

3 Natural Alternatives to Carb Blockers

woman thinking while holding a capsule bottle

Although carbohydrate blockers are an effective way to manage carbs, they are still supplements and should not be substituted for a healthy lifestyle.

Sticking to a healthy balanced diet and regular working out are the only ways to achieve long-term success in weight management and optimal health.

Below are some natural alternatives to carb blockers.

1. Limit Your Intake of Simple Carbs

plate with burger and fries and a woman saying no to it

Simple carbs are directly absorbed into the bloodstream without any form of digestion.

Unfortunately, that makes them nearly impossible to control once they have been ingested.

Foods that contain simple carbs include processed foods, soft drinks, junk foods, and snacks.

By limiting the amount of simple carbs in your diet, you can cut back on calories and move closer to your fitness goals.

2. Ketogenic Diet

keto food in a plate

A ketogenic diet is a special kind of diet focused on inducing ketosis in the body.

Ketosis is a metabolic process where the body turns to fats as the primary energy source for normal bodily functions.

A typical keto diet consists of 65-90% fats, 20-30% proteins, and less than 5% carbs.

By adopting a keto lifestyle, the body is then forced to burn fat for fuel instead of carbs. As a result, it improves blood sugar control and helps in reducing body fat.

3. Paleo Diet

fresh vegetables and tomatoes in a plate

Paleo - also known as the caveman diet, emphasizes consuming natural foods that are not processed or altered in any way.

Any foods that are ingested should be in the same form as the ones our caveman ancestors found.

By eliminating processed foods and grains rich in carbs, you can prevent many of the symptoms associated with excessive carb intake.

Foods that are encouraged include fish, eggs, fruits, vegetables, nuts, and seeds.


Are Carb Blockers Safe?

Carb blockers are generally very safe with minimal side effects such as mild stomach upsets.

Users may experience slight discomfort in their gastrointestinal tract, which disappears over time as the body gets used to it.

Who Should Not Take Carb Blockers?

People who should not take carb blockers include pregnant women, diabetic patients under insulin treatment, and individuals who suffer from gastrointestinal disorders.

These groups should avoid carb blockers or consult a doctor before taking these supplements.

How Often Should I Take Carb Blockers?

It is advisable to take them alongside every meal to experience the full potential of carb blockers.

Additionally, you’ll want to give your body an 8 hour time window between doses to allow ample time for proper digestion.

Lose Weight With Carb Blockers Today

Taking a carb blocker like white kidney bean extract alongside your meals can produce a myriad of positive effects.

Besides reducing the amount of complex carbs in your system, they’ve also been shown to suppress appetite and manage blood sugars - all things that go a long way with healthy weight loss.

Those who prefer a more natural alternative can look towards paleo and keto diets to achieve similar results.

Let us know how well carb blockers work for you.


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