The next time you add Splenda (sucralose), Sweet and Low (saccharin) or Equal (aspartame) to your tea or coffee, beware: all three of these artificial sweeteners also contain dextrose, a simple sugar with about 3.6 calories per serving packet.
A violation of truth in advertising? Not necessarily. The US Food and Drug Administration allows a product to be labeled "zero calories" if the food contains "less than 5 calories per reference amount customarily consumed per labeled serving."
Although these artificial sweeteners do provide fewer calories, they are not calorie free, and people trying to watch their waistlines should keep this in mind.
Although artificial sweeteners are generally considered safe, there is still debate about whether they actually help with weight loss. There is conflicting research about the role diet sodas play in weight loss, with some research demonstrating that consuming diet sodas without decreasing overall calorie intake doesn't appear to promote weight loss, while other studies show some weight reduction when switching from regular soda to diet.
The bacteria in your intestines, known as the gut microbiome, may hold the key to these controversies.
A study last year showed that mice fed artificial sweeteners actually developed higher blood glucose levels than mice fed the simple sugar glucose. When the gut microbiome in these animals was eliminated by antibiotics, the mice fed artificial sweetener did not develop higher blood glucose levels, implying that gut microorganisms play some role in regulating blood glucose levels resulting from artificial sweetener use.
Furthermore, a small study in humans showed that four out of seven lean individuals developed higher blood glucose levels after consuming artificial sweeteners for a week. These data suggest that we are not identical in our gut microbiome and artificial sweeteners may affect us differently.
Until further study more clearly defines how artificial sweeteners alter the gut microbiome and ultimately affect blood glucose levels, it's entirely possible that smaller amounts of table sugar is better for you, since higher blood glucose is a risk factor for obesity and diabetes. The American Heart Association recommends less than 9 teaspoons a day for men and less than 6 teaspoons of table sugar for women.