Fact-checked by Dr. Anthony Gustin, DC, MS.
Written by Lorenz Mac
With the bad rep carbohydrates have gained over the recent years, it’s no coincidence that people are turning to supplements to find a way to enjoy carbs while still losing weight.
But what if you couldn’t even bear the thought of going cold turkey and giving up carbs forever?
Is there really something out there that allows you to eat all the pasta and bread you want without experiencing the negative consequences?
Carb blockers, marketed as weight loss supplements have become increasingly popular in the weight loss industry. So do they work effectively?
In this article, you’ll learn:
Complex carbohydrates are foods that cannot be absorbed by the body unless it’s broken down into simple sugars with the digestive enzyme, amylase.
Carb blockers are amylase inhibitors. And when you consume carb blockers, they block the enzyme alpha-amylase which is produced in your saliva, from attaching to starches and breaking it down into simple carbs the body absorbs.
So by negating the ability for saliva to produce amylase, the food you ate will quickly move out of the body and prevents it from absorbing any calories.
The majority of diet supplements on the market focuses on improving your metabolism to more effectively digest calories. But with carb blockers, the main selling point is the ability to
eat large amounts of carbs without having to count them as calories at all.
There are two main groups of carbohydrates – complex and simple.
Simple carbohydrates are found in processed food such as candy, soda, milk and fruits.
On the other hand, complex carbohydrates are foods that have nutritional value, higher in fiber and also digests slower in the body.
Examples of complex carbohydrates include grains, quinoa, broccoli and beans[*].
When you begin to chew a complex carbohydrate like pasta, grains or potatoes your body starts to produce the digestive enzyme alpha-amylase through your salivary glands. This starts the process of converting complex carbs into simple carbs.
Once the carbs are broken down into smaller simple carbohydrates, the food will then enter your stomach. This is where carbohydrate blockers come into play.
Complex carbs are comprised of a chain of simple carbs linked together. To absorb complex carbs, they need to be broken down by your body’s enzymes.
After ingestion, carb blockers can help stop the digestive enzymes that break carbs down into small, singular units of sugar also known as simple carbohydrates. These complex carbs will go straight into the large intestine without being broken down into simple carbs.
When this happens, they aren’t counted as calories at all.
The mechanism of carb blockers function to only bypass complex carbs and not simple carbs.
So this doesn’t give you an excuse to eat all of your favorite sweet, sugar-filled snacks.
The natural ingredient that most carb blockers are made of is derived from beans, most commonly the white kidney bean extract known as Phaseolus vulgaris [*].
If you search online or at your local supplement store, you’ll notice that almost all carb blockers use white kidney bean extract as the main ingredient. And while supplement manufacturers market an array of different formulas as carb blockers, white kidney bean extract is the only substance that has evidence and studies to back up its claims[*][*].
White kidney bean extracts works by intercepting your pancreas’ ability to produce alpha-amylase. It blocks your body from producing the enzyme needed to digest starches.
Once the white kidney bean extract blocks amylase from breaking down the starches, the food will pass right through your digestive tract without being broken down into a simple carbohydrate and later stored as fat in your body.
One study examined 60 individuals in a randomized, double-blinded, placebo-controlled setting and the results proved that those who were given white kidney bean extract – lost an extra three pounds of body fat while maintaining lean mass[*].
The recommended amount of white kidney bean extract is 1,500 to 3,000 mg per day. A typical dose of one to two capsules, each containing 500 mg should be taken before breakfast, lunch, and dinner[*].
A 12 week randomized double-blind placebo study conducted using the white kidney bean extract supplement Phase 2, demonstrated its effectiveness in blocking carbs. The amount of weight lost by the active group lost an average of seven pounds while the placebo group gained three pounds[*].
Out of the three macronutrients — proteins, fats, and carbohydrates — the body burns carbs off first for energy because it can only hold small quantities of carbohydrate at a time.
Anytime your body is restricted of carbohydrates it starts looking for other sources of fuel for energy and eventually starts using fats for fuel through the process called “ketosis”.
It’s only been in the past couple thousand years that we as humans started eating carbohydrate heavy diets and before that, our ancestors followed a diet very similar to the ketogenic diet.
This is the body’s preferred fuel source for energy.
But once carbs are consumed and turned into glucose, they travel to the small intestine and eventually into your blood. When this happens your pancreas begins to produce insulin, signaling cells to absorb sugar.
The body then immediately makes glucose into energy or converts it to glycogen and gets stored into your liver and muscles. And when your blood sugar lowers your liver will release glycogen.
This repeated cycle will ensure your body has a consistent energy source.
The goal of carb blockers are to prevent carbs from being absorbed into your body. But what’s so bad about carbohydrates?
When you eat an excess amount of calories particularly in the form of simple carbohydrates, your body will reach its’ capacity for storing glycogen. The liver will then resort to converting the stored carbs into fats so the excess energy can be transported to your body’s fat cells for long-term storage.
Your fat cells will release this energy whenever it’s needed. And by eating more calories than your body burns, you’ll keep adding more fat on your body.
Carb consumption also directly influences elevated blood sugar levels, especially in the form of simple sugars. Although glucose behaves as a source of fuel for cells in the body at normal levels, it can act like a poison when there’s a surplus present in your body.
High sugar levels begin to destroy the ability to produce insulin. Your pancreas then starts to overcompensate and creates excess insulin. This can permanently damage your pancreas[*].
Even though carb blockers are mostly marketed as a weight-loss aid, several studies have shown there are more benefits to carb blockers besides helping you lose a few pounds off your waistline.
Research suggests that carb blockers also have the ability to help control blood sugar levels and regulate hormone production.
Can Carb Blockers Aid in Blood Sugar Levels?
Since the mechanism of carb blockers inhibit the digestion of complex carbohydrates, they also function to lower high blood sugar levels in the body[*].
One study found white bean extract helped reduce the glycemic index of white bread. As a result, white bean extract appeared to help normalize blood sugar levels after eating simple carbohydrates[*].
While carb blockers may work in the short term, it isn’t a supplement that should be taken for a long duration.
By following a low carb, ketogenic diet you can experience even better results as compared to supplementing with carb blockers. Adopting a keto lifestyle can normalize your blood sugar levels for as long as you decide to stick to the diet.
Carb Blockers May Help Regulate Hormones
There is evidence showing that carb blockers can help regulate your body’s hunger hormone. A growing number of evidence suggests that using white kidney bean extract reduces the craving for food[*].
A recent study showed that consuming carb blockers, specifically white kidney bean extract, decreased overall feelings of hunger mainly by the suppression of the hunger hormone, ghrelin.
In addition, since carb blockers help carbs pass through to the large intestine undigested, the carbs are considered resistant starches, which have been associated with several health benefits.
Consumption of resistant starches have been linked to reduced abdominal fat and improved insulin sensitivity[*]. When your body becomes more insulin sensitive, the carbs you digest are used more efficiently as a source of energy rather than stored into fat.
While carb blockers are considered to be very safe, that doesn’t mean they won’t come with adverse effects. Because naturally, anything you consume that changes the way your body functions will come with side effects.
Many people have experienced several side effects like lowering blood sugar, diarrhea, bloating, stomach cramping, and gas.
The most common side effects appear to be related to your gastrointestinal system. Side effects such as bloating, stomach cramps, and diarrhea, occur when carbs don’t get absorbed properly in the small intestine. When this happens, the carbohydrates travel to the large intestine and become fermented by bacteria.
Although the fermentation of bacteria can be good for your body in terms of maintaining a strong immune system and gut microbiome, it can also lead to excess gas and digestive issues.
Side effects from carb blockers may vary depending on the frequency and amount you use them. The gastrointestinal side effects are likely to diminish and eventually clear out altogether the more your body gets used to carb blockers.
People Who Should Avoid Them at All Costs
Like any other supplement that impacts the way your body functions, it’s important to see a doctor before you try it out.
If you take insulin or another form of diabetes medication, speak with your doctor before taking carb blockers. There are cases where using carb blockers in conjunction with diabetic medication can lower your blood sugar to critical levels[*].
Use Carb Blockers at Your Own Discretion
With food readily available at the blink of an eye, it has become tougher for our society to maintain a lean physique. People have begun to look for shortcuts to start losing weight while still enjoying sweet, tasty treats.
While carb blockers can help you lose a few extra pounds, it’s not something you should rely on. And while several studies prove that carb blockers will help you lose weight, it isn’t a supplement that will give you consistent results.
Adopting a low carb high fat ketogenic lifestyle is a much safer, dependable weight loss method. Following a keto diet will ensure that you won’t gain all of the weight back once you stop taking carb blockers.
And while there are several studies showing the efficacy of carb blockers to help you lose weight, maintain blood sugar levels and regulate your body’s hormones, they should not be used as a substitute for a healthy, well-balanced diet.
The longer you stick to a ketogenic diet, the easier it becomes and the closer you will be to reaching your weight loss goals.