Even so, keto followers may experience a rise in LDL cholesterol, sometimes called “bad” cholesterol because too much of it can lead to a buildup of plaque in the arteries, which can increase the risk of heart disease. And that’s where fiber can help. However, many high-fiber foods, like beans, fruits, vegetables, nuts, seeds, and whole grains, are also high in carbs, so they're limited on the keto diet.

A close relative of maltose is a molecule known as isomaltose (typically found in items such as beer and honey). The biggest difference between maltose and isomaltose is that isomaltose is joined together by an α-1,6 chemical bond, rather than an α-1,4 chemical bond. Scientists suspected that by adding a certain enzyme (transglucosidase) to high maltose syrup, they could change the bonds from α-1,4 to α-1,6, thereby making it more resistant to being broken down by the enzymes, as described above, when compared to maltose. Again, while this sounds excellent in theory, it is not necessarily what happens in our bodies. In fact, isomaltose (and thus, IMO syrups used in some of these products) is broken down by certain enzymes on the brush border of the small intestine.[2] Though the α-1,6 bond breaks down slower compared to the α-1,4 bond, these IMO syrups, which often use a blend of di-and oligosaccharides, ultimately metabolize into small amounts of glucose and maltose[2] and thus should be viewed as a slow digesting carbohydrate rather than a true fiber.
One of the most common disaccharides (two monosaccharides joined together) is maltose. Maltose is generated when two glucose molecules are linked to one another by an α-1,4 chemical bond (1st carbon is bound to the 4th carbon, making it easily digestible). The type of bond involved in saccharide linkage is critical, as it determines its ability to become hydrolyzed by the enzymes we described above. As such, the α-1,4 chemical bond, as listed in the above example (maltose), has the ability to become hydrolyzed (broken down).
Nutrition DataMacros are provided as a courtesy and should not be construed as a guarantee. This information is calculated using MyFitnessPal.com. To obtain the most accurate nutritional information in a given recipe, you should calculate the nutritional information with the actual ingredients used in your recipe, using your preferred nutrition calculator. You are solely responsible for ensuring that any nutritional information provided is accurate, complete, and useful.
Alex is editor in chief of Bodyketosis, an author, low-carb enthusiast and a recovering chubby guy who reclaimed his health using the ketogenic lifestyle. The need for the keto life began after his aunt and cousin were diagnosed with type 2 diabetes and he was next in line. Through personal experience and extensive scientific research, Alex offers insightful tips for everything keto.
Dr. Ryan P. Lowery is the CEO of Ketogenic.com, author of The Ketogenic Bible, President of the Applied Science and Performance Institute and KetoPhD™. His mission  is to spread awareness around the Ketogenic Lifestyle and its’ many benefits beyond body composition. He earned his BS and MS in exercise physiology and exercise and nutrition science from the University of Tampa and completed his doctorate work at Concordia University in Health and Human Performance with a focus on “The Effects of a Well-Formulated Ketogenic Diet and Exogenous Ketone Supplementation on Various Markers of Health and Body Composition in Healthy and Diseased Populations.” Over his career, Ryan has published over 150 papers, abstracts, and book chapters on human performance and sports nutrition and has dedicated his life to educating the masses. In his free time, Ryan enjoys spending time with his best friend, Scoot the Keto Pup, jet skiing, and traveling around the world. The way to his heart is through a good glass of wine and Keto desserts.
One study compared the glycemic response of SCF to the glycemic response of glucose in 12 healthy adults during a randomized, controlled, crossover study.[6] The findings of this study revealed that SCF had a significantly lower incremental glucose and insulin response than that of the glucose control. Additionally, another study observed a significant lowering effect on postprandial (during or after food consumption) blood glucose and insulin (coinciding with an increase in fat oxidation) upon consumption of 55 grams of SCF in 18 overweight adults, compared to a full calorie control.
We’ve all seen it on food labels: “Only 2 net carbs” or “Low net carbs.” But what does this truly mean? What are net carbs, and why does it matter? Are all net carbs created equal, or are we stretching those claims a bit too much? After reading through this article, I think you will agree that there is a pressing need to educate on the precise definition of net carbs, and what exactly constitutes a true fiber.
The increased awareness regarding the importance of fiber, in addition to its distinct metabolic effects, has resulted in a surge of companies switching to an alternative fiber known as soluble corn fiber (SCF). Interestingly, SCF has been available on the US market since 2007 and is used in foods and beverages across the Americas, Europe, and Southeast Asia. SCF is produced through an extensive process: corn syrup is exposed to a suite of enzymes for at least 48 hours, some of which are found in the brush border of your small intestine, as well as the pancreas.[5] Notably, a large majority of the corn syrup contains easily digestible carbohydrates; however, a small portion is, in fact, not digestible. At the end of this enzymatic exposure, a stream of digestion-resistant carbohydrates remains and is subsequently filtered several times. The resulting product is a “true fiber” that contains a mixture of α-1,6, α-1,4, α-1,2, and α-1,3 glucosidic linkages, which, as mentioned above, contribute to its low digestibility. 

First off, there’s the taste. Consumers want to have their cake and eat it too. At the end of the day, if the sweet indulgence tastes more like a bar of chalk, then there is a high probability that consumers will not be running out to buy it. In my opinion, most companies have nailed this aspect down to some degree. The majority of bars, cookies, or other low-carb snacks that I have tried actually taste really good. However, even if a product can meet the consumer standards with respect to taste and quality, the true separation occurs at the level of fiber source. The buzz words “high-fiber” and “low net carbs” are exploding in today’s society. Thus, companies are attempting to find ways in which they can add fiber to their products, thereby boosting their nutritional profile and simultaneously decreasing the number of net carbs. This now prompts the question: are all fiber sources nutritionally the same, and if not, what does this mean for the consumer?
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As observed by the graphs above, in contrast to the IMOs in which blood glucose rapidly increased to 125 mg/dL, SCF did not elicit any blood glucose response.[9] In addition, while insulin was elevated during the IMO condition, it actually tended to go down in the SCF condition! Despite the results from the blood glucose and insulin responses, the breath hydrogen assay will distinguish which is a “true fiber.” Our data below clearly indicates that SCF indeed passes into the large intestine, as indicated by the large breath hydrogen response. In stark contrast, IMOs do not.

Even so, keto followers may experience a rise in LDL cholesterol, sometimes called “bad” cholesterol because too much of it can lead to a buildup of plaque in the arteries, which can increase the risk of heart disease. And that’s where fiber can help. However, many high-fiber foods, like beans, fruits, vegetables, nuts, seeds, and whole grains, are also high in carbs, so they're limited on the keto diet.


Thus far, we have established what IMO is and how its structure can differ in regard to its carbon bonds. The real question is, “What are the metabolic responses of products that contain these IMOs?” The glycemic index of IMO is very low,[3] however, it has been shown to be nearly completely digested (83 % or more) by enzymes on the small intestinal border.[3] Thus, IMOs should not necessarily be classified as a true fiber but rather as a low glycemic carbohydrate like steel cut oatmeal, at about 3.3 calories per gram.

Non-starchy vegetables are an essential part of the keto diet because they provide essential vitamins and minerals, are packed with antioxidants and provide plenty of fiber. Plus, when you load up on veggies, you are adding volume to your meals so that you feel more satisfied. You are also working to reduce inflammation, increase your antioxidant intake and support the health of your heart.
7. Bouhnik, Y., Raskine, L., Simoneau, G., Vicaut, E., Neut, C., Flourié, B., … & Bornet, F. R. (2004). The capacity of nondigestible carbohydrates to stimulate fecal bifidobacteria in healthy humans: a double-blind, randomized, placebo-controlled, parallel-group, dose-response relation study. The American journal of clinical nutrition, 80(6), 1658-1664.
Breath Hydrogen is an assay that indicates in “real-time” whether or not a particular nutrient is being digested. Upon consumption of a standard carbohydrate (e.g., rice), you can see that it is broken down in the small intestine, and, subsequently, blood glucose rises. If the carbohydrate is not digested in the small intestine, it moves into the large intestine. This indicates that it is a “true fiber.” In the large intestine, bacteria digest the fiber through a process called “fermentation.” In doing so, the bacteria produce hydrogen ions (H+) that circulate into the bloodstream, through our lungs, and is then exhaled outward. We monitored a subject consuming either IMOs or SCF respectively and then tracked the variables listed above for 150 minutes following consumption.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary, and testimonials are not claimed to represent typical results. All testimonials are by real people, and may not reflect the typical purchaser’s experience, and are not intended to represent or guarantee that anyone will achieve the same or similar results.
Dietary fiber refers to nutrients that are not digested by gastrointestinal enzymes. While true fibers are digested, they are not digested in the small intestine like normal carbohydrates, but rather are digested (fermented) by bacteria in the large intestine. True fibers should only be digested by the bacteria in the large intestine. Referring back to the previous example regarding the fitness expos, you can certainly “smell,” and often experience which high fiber bars have some “true” fiber based on the fermentation and digestion.
Nutrition DataMacros are provided as a courtesy and should not be construed as a guarantee. This information is calculated using MyFitnessPal.com. To obtain the most accurate nutritional information in a given recipe, you should calculate the nutritional information with the actual ingredients used in your recipe, using your preferred nutrition calculator. You are solely responsible for ensuring that any nutritional information provided is accurate, complete, and useful.
I’ve been on the Keto zone diet for over 2 months and finally feel energy and a sense of fullness. I have logged purposely the meals you suggested in your book however when I test to see how I’m fairing in fat burning with the ketones sticks I come up in the middle. I tried to adjust here and there to see if my percentages are aligning to the 70-15-15 as you suggest but it still comes up in the middle. In other words I’m average in the fat burning process. Is this just stubbornness on my body’s part?I’m slowly loosing weight but slowly. I exercise but that hasn’t changed anything. Thanks for your help! 

Breath Hydrogen is an assay that indicates in “real-time” whether or not a particular nutrient is being digested. Upon consumption of a standard carbohydrate (e.g., rice), you can see that it is broken down in the small intestine, and, subsequently, blood glucose rises. If the carbohydrate is not digested in the small intestine, it moves into the large intestine. This indicates that it is a “true fiber.” In the large intestine, bacteria digest the fiber through a process called “fermentation.” In doing so, the bacteria produce hydrogen ions (H+) that circulate into the bloodstream, through our lungs, and is then exhaled outward. We monitored a subject consuming either IMOs or SCF respectively and then tracked the variables listed above for 150 minutes following consumption.
Lastly, one of the advertised benefits of IMO is possible prebiotic activity. Prebiotics are critical, as they feed the beneficial bacteria in our digestive system, specifically in the large intestine. These bacteria have several amazing functions, such as lowering body fat, improving insulin sensitivity, and lowering depression. Two “gold standard” prebiotics in the industry are inulin and fructooligosaccharides (FOS). Inulin and FOS are non-digestible carbohydrates that robustly increase beneficial bacteria. The challenge, however, is that both inulin and FOS, due to their rapid digestibility by intestinal bacteria, result in low gastric tolerance, and, ultimately, gastric distress. Additionally, inulin and FOS, when added to protein bars or other goods, may degrade over time into individual sugar units. Regardless, one study comparing inulin to IMOs, found that the prebiotic activity in inulin is 14 times greater than that of IMOs.[4] This is logical because, as you recall from above, approximately 70% to 90% of IMOs are digested. As such, only a small portion of these prebiotic fibers make it to the large intestine, in which two out of three studies have demonstrated that this small portion may indeed have some prebiotic effects.
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