It's hard for me to understand the whole soda phenomenon in Canada and the US. Is it as addictive as cigarettes? Does it make you crave for more? Or it simply tastes so good that you can't get enough of it? Why not eat a bunch of apples instead (if you don't care about the amount of sugar you consume)? Wouldn't they taste better?
Pretty sure it's mostly due to marketing and also vertically integrated markets. You can't get away from soft drink advertising in the US. And the stuff is literally everywhere. In many (most?) restaurants, your beverage choices comprise soda and water. I would not be surprised at all if soda alone accounted for a double-digit percentage of the obesity rate.
This reminds me that in Belgium there's a fast food chain with menus for which the cashier can't swap the soda for water.