I may have a problem—beyond needing a bigger recycling bin. I drink a lot of diet soda. I mean a lot. A couple of 20-oz bottles a day. Sometimes a lot more. (Confession is the first step to repentance, right?)

In a diet, too much of anything is nearly always bad (see: carotenemia). But even modest consumption of diet sodas may cause adverse health effects. We've discussed this before, but a new study in the American Journal of Geriatrics Society links daily diet soda consumption in older Americans to increased belly fat. And belly fat ups your risk of type 2 diabetes, heart disease, and breast cancer.

In the study, researchers tracked San Antonio residents 65 and older for nearly 10 years. Those who drank diet sodas daily gained an average of 3.16 inches around their waist; those who did not drink diet soda gained only 0.80 inches over the same period. ( has more on this belly-fat-diet-soda connection.)

Add this to a growing list of studies that associate diet soda consumption with poorer health outcomes. Last fall, a study in mice suggested diet soda could change the microbes in our bellies and increase the risk of diabetes. Other studies have linked artificial sweeteners to increased appetite and weight gain.

Does this mean diet soda is inherently unhealthy? Not necessarily. Even when researchers take conditions like diabetes, demographics, physical activity, and smoking into consideration, as the researchers in this study did, there are other possible confounders—people who don't drink diet sodas could be healthier or more active in general, for example.

But the evidence is starting to stack up—sort of like my recycle bin. I'm going to go empty this and get a cup of green tea.