By analyzing the results of a 10-year longitudinal study of 474 people, researchers  were able to determine that the participants who drank two or more diet sodas a day experienced a waist size increase 70 percent greater than those who stayed away from diet soda.

Dr. Martin P. Paulus, a professor of psychiatry at the University of California San Diego, and an author of the study, offered this theory as to why something without calories can lead to weight gain:

“Your senses tell you there’s something sweet that you’re tasting, but your brain tells you, ‘Actually, it’s not as much of a reward as I expected,‘ he explained. “So you chase that no-calorie soda with something more caloric, like a salty snack. The sweet taste could also trigger your body to produce insulin, which blocks your ability to burn fat.”

So if you want to lose weight, you should probably think about water.

[Live Science]