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You guzzle calorie-free soda

Artificially sweetened beverages may free of calories, but it doesn't mean they're all that great for your health.

A couple of studies released at the 2011 American Diabetes Association's annual meeting suggest just the opposite. One found that older people who drank lots of diet soda saw their waistlines expand five times more over a decade than their peers who didn't drink diet soda at all, while another showed that mice fed the artificial sweetener aspartame had higher blood-sugar levels.

Next: You drink too much water