Maltitol is a disaccharide (a compound made of two single, simple sugars) made from glucose and sorbitol. This sugar alcohol is commonly used as a sweetener in sugar-free foods. It is roughly 70-90% as sweet as sugar and contains about 2.1 calories per gram, as compared to table sugar, which has 4 calories per gram.
Maltitol and maltitol syrup are not ketogenic friendly sweeteners. You may be wondering why, since other sugar substitutes are ketogenic friendly, and it is the main ingredient in many sugar-free “keto foods”.
Unlike other truly ketogenic sweeteners, maltitol is partially digested and absorbed. Almost half (approximately 45%) of this sugar alcohol is broken down and absorbed into your body. In fact, maltitol has a glycemic index of 52, as compared to sucrose (table sugar) which has a GI of 60. [1]
This means that it is partially broken down into glucose, blood sugar is elevated, and an insulin response is triggered. Consuming these products can cause you to inaccurately count net carbs (which can lead to you getting kicked out of ketosis).
After being consumed, maltitol is hydrolyzed (broken down with water) in the intestines back into sorbitol and glucose. The glucose is completely absorbed, whereas the sorbitol (another sugar alcohol) is only partially absorbed. Any remaining maltitol that has not been broken down is fermented by bacteria in the large intestine. [2] [3]
Because maltitol is partially digested, you can not completely subtract it from your total carbs. However, many people make the mistake of subtracting this sugar alcohol completely from the total carb count, since it is listed as sugar alcohol on the back of the nutrition panel, and most people are taught that net carbs = total carbs – fiber – sugar alcohols. This equation only works when the sugar alcohol (or fiber for that matter) is completely digested, rather than partially digested.
One of the most common side effects of consuming this sugar alcohol is GI issues. Maltitol is a sugar alcohol that draws water from your GI tract, which can cause symptoms like bloating, gas, stomach pains, cramping, and diarrhea (even in small doses). In fact, if you have ever looked at the back of a sugar-free candy package (that contains this sugar alcohol), you will notice a warning label that clearly states this product may have a laxative effect.
One of the most common culprits of maltitol consumption is sugar-free candy. Even candies that claim to use stevia on the front of the package may still contain this sugar alcohol.
Some common sugar-free products that are marketed as keto-friendly (but should actually be avoided because they contain maltitol and can kick you out of ketosis not to mention leave you in the bathroom for hours) include the following:
Have you experienced the negative effects of this sugar alcohol? Comment below and share your story!
Livesey G. Health potential of polyols as sugar replacers, with emphasis on low glycaemic properties. Nutr Res Rev. 2003 Dec;16(2):163-91. doi: 10.1079/NRR200371. PMID: 19087388.
Leone, A., De Amicis, R., Lessa, C., Tagliabue, A., Trentani, C., Ferraris, C., Battezzati, A., Veggiotti, P., Foppiani, A., Ravella, S., & Bertoli, S. (2019). Food and Food Products on the Italian Market for Ketogenic Dietary Treatment of Neurological Diseases. Nutrients, 11(5), 1104. https://doi.org/10.3390/nu11051104
Mäkinen K. K. (2016). Gastrointestinal Disturbances Associated with the Consumption of Sugar Alcohols with Special Consideration of Xylitol: Scientific Review and Instructions for Dentists and Other Health-Care Professionals. International journal of dentistry, 2016, 5967907. https://doi.org/10.1155/2016/5967907