Short answer: If you regularly drink soda, then diet soda is a better option than regular soda; however, adding diet soda to your diet is not beneficial.
Longer answer: Diet soda began to appear in the late 1950s and early 60s in the U.S. It was initially marketed as a diabetic soda, but the low caloric content appealed to people with a desire to live a healthier lifestyle while still enjoying a classic American beverage. Diet soda is able to maintain a similar taste to regular soda by substituting sweeteners like saccharin, which is so sweet in low concentrations that it doesn’t have any calories. Most sweeteners are hundreds, if not thousands, of times sweeter than sugar, which drastically reduces the amount of artificial sweetener needed to achieve the desired taste. However, sodas with artificial sweeteners still cause tooth decay and other detrimental health effects linked to soda. Furthermore, diet soda is associated with metabolic syndrome, a set of conditions that increase the chance of heart disease or diabetes. It is suggested that this could be the case because diet soda could cause some consumers to falsely assume that it enables them to eat more than they usually do. It has also been suggested that the incredible sweetness of the artificial sweeteners triggers the body to crave more sweet things. Either way, diet soda is better for you than regular soda, but it will not bring any nutritional value to your diet.