The Truth About Diet Soda The authors of Eat This Not That reveal some hard truths about low-calorie sodas. By Dave Zinczenko and Matt Goulding, Men's Health

Hard truth No. 1

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. Considering there are 15 calories in every teaspoon of sugar, that's not good news if you're watching your weight.

Hard truth No. 2

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

Diet soda is 100 percent nutrition-free—and it's important to remember that all that useless liquid is taking up space that could have gone to more healthy alternatives. On the positive side, it means you won’t be taking in equally non-nutritious, calorie- and sugar-packed options. But 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, which is high in antioxidants.

Hard truth No. 3

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. Check out our guide to the 11 most controversial food additives to see how aspartame stacks up.

1. Acesulfame Potassium (Acesulfame-K) 2. Artificial Flavoring 3. Aspartame 4. BHA and BHT 5. High Fructose Corn Syrup (HFCS) 6. Interesterified Fat 7. Monosodium Glutamate (MSG) 8. Partially Hydrogenated Vegetable Oil 9. Red #3 (Erythrosine) and Red #40 (Allura Red) 10. Saccharin 11. Yellow #5 (Tartrazine) and Yellow #6 (Sunset Yellow

The bottom line is this: Diet soda does you no good, and it might just be doing you harm. The best way to hydrate is by drinking low-calorie, high-nutrient fluids—and choosing healthy alternatives.....