This is a tough one, because we get conflicting opinions on the topic of soluble corn fiber (SCF), also known as resistant maltodextrin, which is different from regular maltodextrin. Although this substance is used by many so-called health food companies, we should be really examining whether it is a substance that we should be eating on a keto diet. Soluble corn fiber is super cheap and used by food companies to thicken and preserve processed foods. It also causes lower spikes in blood glucose than IMO’s, which is why Quest Nutrition replaced IMO’s in their foods with soluble corn fiber. Some people say soluble corn fiber is allowed on a keto diet because it is not the same as corn, but rather fiber that is extracted from corn with a low net carb profile.
In general, dietary fiber, which is found mostly in vegetables, fruit, legumes and grains, is known for helping bowel movements, lowering cholesterol, and balancing gut bacteria. All fiber is non-digestible, and soluble corn fiber is no exception. However, soluble corn fiber, unlike dietary fiber, actually spikes your blood glucose levels. Compared to white sugar though, it is lower on the glycemic index at 25, compared to white sugar, which is 100. Even so, this is enough to possibly knock you out of ketosis. Also soluble corn fiber is not a natural substance. It is processed from corn syrup, which is already a chemically processed substance.
Are there any benefits to eating soluble corn fiber? Some say it acts as a prebiotic fiber, but there are plenty of other natural options that work better. Some better high fiber and natural foods include: avocado, broccoli, cauliflower, zucchini, eggplant, coconut meat, etc.
All in all, low amounts of soluble corn fiber might not do damage to your diet, but in sufficient amounts it could cause harm. So it is best to avoid soluble corn fiber and other substances of similar nature. Also, different people have different body chemistries, so everyone needs to experiment with different foods and ingredients and analyze how it effects them to determine what is beneficial for them and what is not.