Just a short walk from Templeton Secondary, students are lured by the siren call of a salty snack.

But most kids aren't so sure about what's in their after-school snack. And what's in it can hurt you: Trans fats.

Trans fats clog arteries, contribute to obesity and are linked to heart disease and stroke.

A federal task force on the subject advises the level of trans fats should not exceed five percent of any food item.

Traditionally, fast food has been loaded with trans fats. We did our own testing to see just how bad it is.

A&W and KFC fell within the recommended guidelines in a typical meal of fries and chicken nuggets or chicken strips.

But McDonald's apple pie contains 6.95 percent trans fat, exceeding the guidelines by nearly two percent.

At Burger King, while individual items might fall under the five percent rule, a combined meal of French fries, chicken tenders and an apple turnover puts you over at 5.48 percent.

In January, Calgary became the first city in the country to regulate trans fats. Burger King has already eliminated them in its Calgary locations, but failed to answer why that couldn't happen here.

Burger king refused an on-camera interview but promises, by email, it will achieve a trans fat free menu this year.

McDonalds also declined an on camera interview. In a written statement, it says they are working to decrease combined levels of both saturated and trans fats by the end of 2008.

In December 2007, health minister Tony Clement said "families are looking for healthier food options."

The federal health minister has given the food industry until June 2009 to adopt the recommendation.

And he isn't alone. More and more Canadians are seeking to reduce trans fats from their diets.

One consumer advocate argues Ottawa is moving too slow, and says if Calgary can make a law reducing trans fats right now, the federal government should too.

"If it's dangerous, it's not going to get any better," says Bruce Cran of the Consumers' Association of Canada.

"That's a long time to allow a product like this to continue to be used," he says.

In the meantime, it's ultimately up to consumers to protect themselves.

With a report from CTV British Columbia's Joanne de Frias