But labels don't have to reveal how much caffeine the products pack ... (Our shoppers usually found energy drinks near soda and juice, sometimes at checkout, and less often near alcoholic beverages.

One 8.3-ounce (0.25-liter) can has two to three times the amount of caffeine as a 12-ounce (0.35-liter) can of soda. "The kids in ... to be labeled "high caffeine content" drinks.