We’ve all heard it before: diet soda is bad for you, and water is always the healthier choice. But a recent study challenges that assumption—at least for some people.
The Study, Simplified
Researchers studied adults with well-controlled type 2 diabetes who regularly drank diet beverages. Half were asked to switch to water, while the other half continued drinking artificially sweetened drinks. After 24 weeks, the results were surprising.
Those who kept drinking diet beverages showed slightly better blood sugar control than those who switched to water. The water group’s glucose markers actually worsened a bit. The study was well-designed, independently funded, and fairly large, making the findings worth paying attention to.
What This Does—and Doesn’t—Mean
This doesn’t mean diet soda is “health food,” or that everyone should choose it over water. The effects were small, and the study only applies to people with stable type 2 diabetes. But it does suggest something important:
Switching from diet soda to water doesn’t automatically improve health—and may not help glucose control at all.
At best, diet drinks might help some people manage cravings or avoid sugary alternatives. At worst, they seem to be no worse than water for blood sugar control in this specific group.
The Bigger Takeaway
Nutrition isn’t one-size-fits-all. A single study won’t label a food as “good” or “bad” forever—but it can remind us to question assumptions. For people with well-managed type 2 diabetes, giving up diet soda for water may not be the upgrade it’s often made out to be.
Sometimes, the healthiest choice is the one that actually works for you.
