Will carbonated drinks really cause you to add on pounds?

It is not the carbonation that is the problem. Most pop (soda for you Americans) is mostly just sugar water - and a lot of sugar at that. However, as there is almost no nutrition in them beyond sugar, you still need eat to get what your body needs for the day. Like most very sweet foods, pop just adds pounds, and not much else.

Of course, it depends on how much you drink, etc. Coffee or tea with a spoon of sugar has about 1/5 the calories of pop. (Rough estimate.)

I drink the diet stuff myself. No nutrition, but no sugar either.

it's the sugar that's associated with the carbonated drinks that makes people gain weight. if the excess sugar isn't metabolized, you body stacks it up in the form of fat.

only diet

it hold in the fat