Why do we keep drinking diet soda? (Photo: Getty Images)Yet another study confirms what people have been saying for ages: Stop drinking diet soda. Like, right now. Drinking just one 12-ounce can of an artificially sweetened fizzy drink per week can increase your risk of Type 2 diabetes by 33 percent, French researchers found, and given that most people don't stop at a single weekly serving, your real risk for diabetes could actually be much higher.