The Truth About Diet Soda

By David Zinczenko, with Matt Goulding
We talk a lot about ''watching what we eat,'' but if you never gave a thought to what you ate and instead watched only what you drank, you could probably cut 450 calories a day out of your life. (Yes, nearly a pound of fat loss a week!) That's what a study from the University of North Carolina found. Americans today drink about 192 gallons of liquid a year—or about 2 liters a day. To put it into perspective, this is nearly twice as many calories as we did 30 years ago.

When confronted with the growing tide of calories from sweetened beverages, the first response is, “Why not just drink diet soda?” Well, for a few reasons:

Just because diet soda is low in calories doesn't mean it can't lead to weight gain.

It may have only 5 or fewer calories per serving, but emerging research suggests that consuming sugary-tasting beverages--even if they're artificially sweetened--may lead to a high preference for sweetness overall. That means sweeter (and more caloric) cereal, bread, dessert--everything.

Guzzling these drinks all day long forces out the healthy beverages you need.

Diet soda is 100 percent nutrition-free, and again, it's just as important to actively drink the good stuff as it is to avoid that bad stuff. So one diet soda a day is fine, but if you're downing five or six cans, that means you're limiting your intake of healthful beverages, particularly water and tea.


There remain some concerns over aspartame, the low-calorie chemical used to give diet sodas their flavor.


Aspartame is 180 times sweeter than sugar, and some animal research has linked consumption of high amounts of the sweetener to brain tumors and lymphoma in rodents. The FDA maintains that the sweetener is safe, but reported side effects include dizziness, headaches, diarrhea, memory loss, and mood changes. Bottom line: Diet soda does you no good, and it might just be doing you wrong.