Americans drink almost a quarter of their daily calories. If you're tired of water or seltzer but don't want the calories of high-sugar drinks, be careful. Good Housekeeping has discovered that some drinks that sound low-cal might not be.

"A lof of the drinks that you see in the supermarket may look light and fruity. They may have "organic" or "all-natural" on the label, but they still can have a lot of calories," says Delia Hammock, R.D., nutritionist, Good Housekeeping Institute.

We asked consumers to guess which tea drink was higher in calories: the Inko's 100 percent Natural White Iced Tea or the Snapple White Tea. "The Snapple actually says it is a third less calories and sugar, but the Inko's has half the number of calories as the Snapple," says Hammock.

How about Newman's Own All Natural Lightly Sparkling Orange Mango and Luna Nutritional Mandarin Orange Iced Tea for Women? "My guess would be that the Newman's Own is more calories," says one tester. "Partly because the Luna says that it's 70 percent organic and that it's only 50 calories."

The Luna does have about 50 calories per bottle as it claims, and the Newman's Own has 260 calories per bottle, which is about five times as much. While part of that is because the bottle of Newman's Own is larger, the real culprit is the sugar. There is a lot more sugar in the Newman's Own beverage.

Fear not. Good Housekeeping says you don't have to give up taste to get low-calorie drinks. Just make sure you read the label. And check out the serving size as well. Sometimes one bottle or can is a serving, but sometimes a serving is less than that. So what looks like a low calorie-count may actually be high if you drink the whole thing.

To learn more, check out the August issue of Good Housekeeping or visit www.goodhousekeeping.com.