Artificial sweeteners – in various forms – are pretty ubiquitous these days, showing up in nearly every food out there. These substances have even managed to find their way in to so-called “diet,” “health” and fitness foods – which actually makes sense on paper. After all, most artificial sweeteners have virtually no caloric value, making them the obvious choice from individuals who want something sweet while trying to cut calories. Unfortunately, artificial sweeteners tend to carry more problems than benefits. In fact, these chemicals can often be counterproductive – working against the very goals they claim to support. This contradiction is especially strong in protein supplements, where artificial sweeteners are commonly used. But what, exactly, is the problem with the inclusion of artificial sweeteners in protein supplements and other foods? Risk of Obesity, Diabetes and The Like Although people have had their suspicions about artificial sweeteners for years, things really started to go downhill for the additives when evidence linked diet sodas with an increased risk of obesity and diabetes. But, many wondered, how is that possible? The artificial sweeteners have few calories and aren't processed like sugar so how can that make any sense? Researchers are still attempting to answer that question full, but our understanding of the full issue is slowly growing. In May of 2015, for instance, scientists found that artificial sweeteners have a powerful negative effect on the bacteria that natural inhabits the human digestive tract. While these critters normally support our metabolism and other functions, evidence suggests that artificial sweeteners can change this usually positive behavior. After being exposed to artificial sweeteners, gut bacteria extract more calories from food then they normal would and can even increase the amount that gets stored for fat. Now, this is always a bad thing – of course. But when an ingredient in protein supplements, which are normally taken to help achieve and maintain a healthy body weight, has this effect it should be definitely be avoided. There is also some evidence that a small amount of these artificial sweeteners does get caught by your immune system and used for fuel, covertly contributing to your caloric intake for the day. In some cases, such as acesulfame, the small percent that does get absorbed can negatively impact hormonal responses. Other Issues The thing to remember when dealing with nutrition in general, is that a substance may be completely harmless when it enters your body but then create harmful byproducts. A prime example of this is the artificial sweetener, aspartame. A fairly simple compound, aspartame is made of two amino acids and methanol. Your body makes good use of the amino acids, of course, but the methanol presents a problem. When this substance is broken down by your body it produces two toxins: formaldehyde and formic acid. While it is true that these substances are naturally present in your body at low levels, it's also true that it doesn't take much for concentrations to rise beyond what your body can handle. Read More: Cheap Protein Supplements to Avoid The 5 Biggest Protein Powder Myths Why Hydrogenated Ingredients in Protein Powders Are Bad