Recent research again confirms what many previous studies have concluded: diet soda tends to promote weight gain rather than prevent it. In this study¹,²,³,⁴,⁵,⁶ diet soda consumption was linked to increased belly fat in Americans over the age of 65.

Abdominal fat (visceral fat) is associated with an increased risk for diseases such as heart disease, diabetes, and cancer, just to name a few, and your waist-to-hip ratio is one potent indicator for your level of risk for these and other chronic health problems.

Diet Soda Increases Hazardous Belly Fat in Aging Adults

Seniors aged 65 and over were followed for an average of nine years, and while the study was an observational one and hence cannot prove causation, the authors note that there was a “striking dose-response relationship” between diet soda consumption and waist circumference.

This held true even when other factors such as exercise, diabetes, and smoking were taken into account:

     •   People who never drank diet soda increased their waist circumference by an average of 0.8 inches during the nine-year observation period
     •   Occasional diet soda drinkers added an average of 1.83 inches to their waistline in that time period
     •   Daily diet soda drinkers gained an average of nearly 3.2 inches—quadruple that of those who abstained from diet soda altogether

What’s worse, abdominal fat gain was most pronounced in those who were overweight to begin with. According to senior author Dr. Helen Hazuda:7

“People who are already at cardiometabolic risk because they have higher BMIs are really in double or triple jeopardy. When they think they’re doing something good by drinking artificially sweetened beverages, it’s actually totally counterproductive.” [Emphasis mine]

This isn’t the first time diet soda has been linked to expanding waistlines. One 2011 study, in which soda drinkers were followed for nearly 10 years, found that those who drank diet soda had a 70 percent greater increase in waist size compared to non-diet soda drinkers.

Those who drank two or more diet sodas a day had a 500 percent greater increase in waist size. According to earlier research, drinking just one diet soda a day may raise your risk of obesity by 65 percent. Diet soda consumption has also been linked to a 50 percent increased risk for stroke.