Coca-cola was invented in 1886, and became a popular fountain drink by 1900.  It, and other carbonated beverages, were regularly sold and consumed by the American public for decades afterward without causing obesity.  The problems came about in the 1970s after the companies switched to a high calorie sweetener made in the laboratory, rather than gleaned from nature.  Obesity rose rapidly after soft drinks all contained this cheaper alternative to sugar.  We need to ban high fructose corn syrup, as it seems to be the main reason for obesity, not sugar.  Our bodies handle natural sugars differently than it does this starch chemically exploded into sugars, as those sugars are not natural.