Erythritol is usually made from plant sugars. Sugar is mixed with water and then fermented with a natural culture into erythritol. It is then filtered, allowed to crystallize, and then dried. The finished product is white granules or powder that resembles sugar. Most erythritol is 70% as sweet as table sugar, yet it is virtually non-caloric, with only 2 calories per gram, according to the FDA.  It has not been found to affect blood sugar or insulin levels and has a zero glycemic index. In reasonable amounts, erythritol doesn’t cause digestive upset and diarrhea that other sugar alcohols like sorbitol and xylitol are known to cause. This is because erythritol is a smaller molecule and 90 percent of erythritol is absorbed in the small intestine and for the most part excreted unchanged in urine. This quality makes erythritol unique among the sugar alcohols.  Erythritol isn’t metabolized by oral bacteria, which means that it doesn’t contribute to tooth decay.   Excessive consumption of erythritol (over 80 grams per day) may result in digestive upset, diarrhea, and bloating.