Caffeine Myth No. 5: Caffeine Has a Dehydrating Effect
Caffeine can make you need to urinate. However, the fluid you consume in caffeinated beverages tends to offset the effects of fluid loss when you urinate. The bottom line is that although caffeine does act as a mild diuretic, studies show drinking caffeinated drinks in moderation doesn't actually cause dehydration.
Caffeine Myth No. 6: Caffeine Harms Children, Who, Today, Consume Even More Than Adults
As of 2004, children ages 6 to 9 consumed about 22 milligrams of caffeine per day. This is well within the recommended limit. However, energy drinks that contain a lot of caffeine are becoming increasingly popular, so this number may go up.
Some kids are sensitive to caffeine, developing temporary anxiety or irritability, with a "crash" afterwards. Also, most caffeine that kids drink is in sodas, energy drinks, or sweetened teas, all of which have high sugar content. These empty calories put kids at higher risk for obesity.
Even if the caffeine itself isn't harmful, caffeinated drinks are generally not good for kids.