B.C. nutritionists are warning teenagers to stay away from protein powders and pre-mixed supplement drinks that may have unregulated ingredients, and may end up just making the teens ill, or just fat.

Dietician Ashley Charlebois said health and muscle-conscious teenagers might unknowingly be wasting money on expensive protein supplements without knowing what they're getting out of them.

"What is kind of contra-indicative to what most people think is [that] what is important is to actually get carbohydrates after a workout rather than protein," she said.

Charlebois said there could be many potentially dangerous additives hiding in protein shakes despite the fact that Health Canada regulated health supplements. Not all manufacturers list all their ingredients, he said.

Charlebois named creatine as one that teenagers and their parents should watch out for, as it can cause dehydration.

And some protein supplements have the power to go straight to the hips.

Teenagers can only synthesize 15 grams of protein at a time, but many who are trying to gain muscle take more than that.

Antonio Farina, a Vancouver-area teen, exercises eight times a week and plays AAA hockey.

He thinks he's skinny and has a hard time gaining muscle, so he drinks shakes with 30 grams of protein after every workout.

"Definitely can't do anymore wrong — just build a bit more mass," he said, in-between swigs.

According to Charlebois, the excess protein Farina can't absorb will turn straight into energy — which, if it isn't used up right away, will be stored in the body as fat.

But Farina, who has gained eight pounds he attributes to the shakes, thinks they're making him stronger. He plans to continue the regimen he's established, and says he won't be doing it alone.

"There's roughly 17 guys on my hockey team. At least 15 of them take some sort of pre-workout or post-[workout] [shake] with protein and I have a lot of friends that work out with me and take it as well," Farina said.

Do the research

Greg Semkuley, the sales manager for Enerex nutritional supplements in Burnaby, said that teenagers can benefit from health supplements, if researched and taken properly.

"These things aren't a replacement for food and good nutrition on a daily basis," Semkuley said.

"They're not a substitute for a good nutritious meal, but when you are having athletes that are performing to a much higher degree, and the demands on their body are much higher, then — yeah — there are supplements that can be looked at."

Semkuley said teens should research what kind of supplement they're buying, and only use what is safe.

But, if someone has a thin frame or a small body type, there's nothing supplements can do to change that, he said.

With files from student Andrew Chang, reporting for CBC's News Day in B.C.