[antisthenes]

What about a medium sized soda at a fast-food place? Those places use consumer surplus as an incentive to get a larger drink, so seeing people with huge cups, presumably filled with soda is very common.

Besides, 140 calories is a lot, considering it has about the same calorie density as milk and the number of great drinks available to you at 0 calories, like black tea, green tea, coffee and plain water.

Soda is sugar only, always, so it's much easier to throw your daily balance of carb/protein/fat off with soda than any other drink (e.g. milk).