The Aussie study team split roughly 100 people—all regular soda and caffeine drinkers—into two groups. The researchers supplied everyone with soda, and told each person to drink as much or as little of it as desired during the month-long study period. The catch: while all the soft drinks tasted exactly the same, one group received caffeinated soda while the other received non-caffeinated soda. Compared to the caffeine-free soda drinkers, the people given caffeinated soft drinks consumed 53% more—or nearly 5 more ounces a day—during the study period. MORE: Your Body On Diet Soda (Infographic) “The concentration of caffeine in soda is too low to change the drink’s flavor,” says study coauthor Russell Keast, PhD, a nutrition scientist at Deakin University. But, Keast adds, there IS enough caffeine in soda to temporarily rev up your brain and body, and cause all the positive changes people usually associate with a little caffeine jolt. Your body gets used to and craves that little jolt, even if you aren’t aware of it. And that leads to greater consumption, Keast says. While his study didn’t look specifically at people who switched from caffeinated to non-caffeinated soda, Keast says it makes sense that ditching caffeine would help you limit your soda habit. He also adds that caffeine is an additive in soda—meaning it’s not a natural element of your soft drink. “If caffeine were removed from soft drinks, sales would decrease,” Keast says.MORE: 7 Side Effects of Drinking Diet Soda
