Many people believe that diet soda is healthier than regular soda because it contains less sugar and fewer calories. However, several scientific studies have found that diet soda may be associated with diabetes, weight gain, and heart disease. In fact, those who drink one diet soda per day have an increased risk of heart attack and stroke compared to those who do not drink diet soda each day or at all. What claim is being made? Diet soda is healthier than regular soda. Diet soda tastes better than regular soda. Diet soda may increase the risk of disease. Diet soda may contain more calories than regular soda.