Ask middle school students -- like those Tuesday in a Philadelphia tour group from Drexel Hill -- about their soft drink of choice and you might get an answer something like this:

"Well, I like me a quality drink like grape soda ... coke and iced tea ... yeah, I like that fruit punch too!"

Had this group ever heard of Marley's Mellow Mood? There was a resounding, "No!"

The beverage Marley's Mellow Mood, named after Bob Marley, contains herbal relaxants and is promoted as a stress reducer. It's not intended for children.

A middle school in Holmdel, N.J., learned this the hard way when several students purchased the beverage at school and were sickened by it Friday.

While an investigation is pending at Satz Middle School, a registered dietitian says there's good reason not to serve such drinks.

"We're really looking at a product that is not much different from soda," said registered dietitian Althea Zanecosky.

While the drink's main ingredients are water and sugar, it also contains a few herbal compounds, including valerian root and chamomile, known as mood soothers.

Zanecosky says the drink is fairly innocuous, though some people could have a sensitivity to any of its ingredients. Its worst offense, she says, is that it's a bottle full of empty calories. Still, she says, something that says it's not for kids, is not for kids.

"Where we run into a problem is kids want to drink what they see adults are drinking. Unfortunately, kids are not little adults. Their metabolic processes are very different from adults, so these are not drinks that are appropriate for kids," she said.

Zanecosky says if you really want to relax, then turn to exercise. And if you're on the opposite end of beverage preferences, looking for energy from a Monster or Red Bull rush -- take a nap.