"Caffeine stimulates the central nervous system, so 'It's a good idea for people to know how much they're taking,' said Jackie Buell, director of sports nutrition at Ohio State University. ... Symptoms of ingesting too much caffeine, called caffeine intoxication, include nervousness, anxiety, diarrhea, tremors, insomnia and a rapid heart rate. ... Poison-control centers now regularly field caffeine-related calls involving teens."
Jolted by studies, researchers want caffeine labels on energy drinks by Kevin Mayhood