Also be very careful to read the serving sizes. I don't know about actually healthy drinks, but things like Gatoraid are for 1/2 a cup, and most people drink the whole bottle which is 2 or even 4 servings. It's a gimmick for them, but worth verifying on your drink.
"natural" fruit sugars are more healthy than added white sugar, but only by a bit. sugar is sugar. and the fact that it is in juice form, means it will go right to your blood stream unless you are eating it with food.