Sugary drinks are the most fattening things you can put into your body.
This is because liquid sugar calories don’t get registered by the brain in the same way as calories from solid foods (1).
For this reason, when you drink soda, you end up eating more total calories (2, 3).
Sugary drinks are strongly associated with obesity, type 2 diabetes, heart disease and all sorts of health problems (4, 5, 6, 7).
Keep in mind that fruit juices are almost as bad as soda in this regard. They contain just as much sugar, and the small amounts of antioxidants do NOT negate the harmful effects of the sugar (8).