Sugar is a problem health-wise, especially high fructose corn syrup, etc. But then again, a lot of processed foods are bad for you too. Soda is only one small part of the obesity epidemic in this country. Computers, TV, video games, fast food, processed food, GMO produce, all this play a part in eating crappy food and living a sedentary lifestyle. THAT is what leads to obesity.
Buy and cook healthy ingredients, push back from the table a few minutes earlier, and get your fat *** out from in front of the TV for a brisk 30 minute walk. I know from personal experience that what I'm recommending is easier said than done.