Is Diet Soda Bad for You?

Q. Is it true diet sodas are more fattening than regular soda?
-- Geraldine, Glenside, PA

A. Zero calories, it turns out, don't have zero impact when it comes to weight. We recently spotted a study where people who drank diet sodas had a 70% greater increase in waist circumference over a few years than people who didn't drink them. You know how we feel about waist size: Any excess fat is bad, but belly fat is the worst. It's linked to diabetes, heart disease, and some cancers.

Here's your real question: How can something that's basically chemicals and coloring be fattening? Here's our answer: First, sweet diet soda fuels your desire for other sweets. Second, it has a "health halo" effect. You view choosing a "diet" drink as virtuous (all those calories saved!). So it feels like you can afford to reward that virtue with a hot fudge sundae or a fast-food burger that's bigger than Texas.

It's not the diet soda that's fattening. It's the sense that drinking it somehow erases the calories of what you eat with it. A diet drink now and then won't make you fat . . . as long as you're not using it to wash down a fried calorie bomb from the drive-through.

Before you buy your next six-pack of diet soda, know these pros and cons.