A new study that was published in the European Journal of Endocrinology finds that individuals who consume more than two soft drinks a day, regardless of whether the beverages contain sugar or artificial sweeteners had a twofold greater risk of developing type 2 diabetes than those who consumed fewer than two drinks daily.
Lead study author Josefin Edwall Löfvenborg said she was "somewhat surprised" and the there could be a number of possible explanations "One is that consumption of diet soft drinks may stimulate appetite and make us increase our food intake, especially sweet/sugary foods, possibly leading to overweight, which is a risk factor for diabetes," and "Another one is that artificial sweeteners may negatively affect the balance of 'good' and 'bad' species of microbes in the gut, which could lead to glucose intolerance."
Another reason could also be that people have swapped from sugary to diet soft drinks in an attempt to prevent further weight gain could also be a cause.