You can easily make lemonade at home, and use far less sugar than what was likely in the drink you had. Just start with a recipe like this, only put in less sugar, adding more till it becomes palatable. It will taste a LOT better , too. (My 4yo DD is a huge lemonade fan!) (Don't worry about the fact that AU measurements aren't the same as US- this is a pretty flexible recipe, so as long as you taste while you are making, it should turn out fine.)
Tasty Lemonade
INGREDIENTS:
6 lemons, juiced
1 1/2 cups water
1/2 cup brown sugar
1/2 cup ice cubes
In a large pitcher, combine fresh lemon juice and water. Stir in brown sugar until it dissolves. Stir in ice cubes.
Also, you could easily use whatever sugar- doesn't need to be brown. Just don't use powdered.