What's worse?
 

drinking 12 diet cokes a day and one glass of water.

smoking 12 cigarettes a day and drinking 8 glasses of water and no sodas.

They're both stupid.

Hmmm... that's a tough one. Diabetes vs. cancer..... neither one can really be validated.

One mans stupidy is another mans nervana - Kirk Cobain

both examples are the same..

both habits were designed to kill you.

smoke a joint and drink some green tea.

Diet Coke doesn't cause Diabetes. They use chemical sweeteners instead of sugar, either Splenda (Surcralose) or Aspartame, depending on which company's products it is.

Aspartame has been shown to create formaldehyde on the frontal lobe of rats, while Splenda no one knows the long term effects of since Pepsi rail-roaded it through FDA approval via some very expensive lobbying.

Still, it's all about odds. What are the odds that you're going to contract a major disease or cancer from smoking a pack of cigarettes a day...50/50? Worse?

Versus the odds of all this chemical sweetener intake leading to something on that magnitude...

Yep, the Diet Cokes win. Have at it. Good luck, hope you don't roll a seven and crap out. :)

I would say the pop. everybody has a vice

both are worst for your body...