A recent study showed that artificial sweeteners do not prevent obesity but may actually promote metabolic disorders such as type 2 diabetes. Calorie-free sweeteners are often used to lower caloric intake and are commonly thought not to raise blood sugar levels. In a recent issue of the journal Nature, researchers reported that artificial sweeteners increased the blood sugar levels in both mice and humans by interfering with microbes in the gut. More research needs to be done but the research so far has been highly indicative of a relationship between the intake of artificial sweeteners and blood sugar intolerance; a precursor to metabolic diseases. Here's a link to the original article.