More bad news on the health effects of diet soda, specifically in regard to people 65 and older. Those who drink the stuff daily gain significantly more belly fat—a particularly dangerous kind of fat, say researchers in Eureka Alert. Specifically, study subjects who drank diet soda every day gained 3.2 inches around the waist over a decade, compared with 0.8 inches for those who drank none. Occasional drinkers fell between the two at 1.8 inches. That's especially troubling because belly fat is linked to an increased risk of cardiovascular disease and other health ailments including diabetes, says one of the researchers at the University of Texas Health Science Center at San Antonio.
So why does "diet" soda cause weight gain? That part remains unclear, but another researcher explains to Time that the artificial sweeteners used to replace sugar might be messing with the body's natural signals. “Your body is used to knowing that a sweet taste means you are ingesting energy in the form of calories that, if you don’t burn them off, is going to convert to fat," she says. The artificial sweeteners might confuse that message. For those hooked on the taste, the study team recommends eating sweet fruit and washing it down with water, and those who drink diet soda for a jolt can shift to tea or coffee, reports LiveScience. (Another study found that artificial sweeteners might actually raise blood-sugar levels.)