How do sugar alcohols affect ketosis?

Although mainstream keto diets (like Atkins) say to remove sugar alcohol carbs from the “net carb” amount, I don’t feel that is always appropriate.  Some sugar alcohols do not affect blood glucose and insulin levels, so they can be safely subtracted, but others can break ketosis. 

Maltitol is the sugar alcohol most likely to kick you out of ketosis.  It has a GI of around 52 (depending on the preparation, ie syrup) and has a large laxative effect.  Want to guess which sugar alcohol is used the most in sugar-free candy?  Yep, maltitol. 

That is one of the reasons we can’t say sugar alcohols are all keto friendly.  This is one sugar alcohol (along with the rarer hydrogenated starch hydrolysates, or HSHs like polyglycitol) that should be avoided on keto.  It is nearly as bad as table sugar in regards to breaking ketosis.

For a more in-depth review of which sugar alcohols are good, please see the article “What are Net Carbs and why do they matter“. It also discusses the Glycemic Index (or GI) and how you can use it to evaluated sugar substitutes, like sugar alcohols.   GI is also very useful when evaluating food to see what its impact will be on your ketosis levels.  

Although most sugar alcohols don’t affect ketosis, that isn’t the case for all of them.  However, that doesn’t mean they are a “free” food, as they can have some unpleasant side effects. 

For example, google “sugar-free gummy bears review”.  The stories may be funny, but there is a reason there are a lot of YouTube “challenges” involving the sugar-free gummies…

*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.