While store-bought packaged food has to have trans levels labelled at point of sale in Canada, restaurant and fast foods are not required to follow the same rules. And trans fats are still widely used in take-out food. (See the latest news story, Trans fat levels alarming in some Canadian fast foods)

Fats in foods are made up of four different types: Polyunsaturated, monounsaturated, saturated and trans. Trans fats are found naturally in some animal-based foods, but their most common appearance is in the fats formed when liquid oils are made into semi-solid fats like shortening and hard margarine.

Nutritional scientist Bruce Holub says studies show just 5 grams a day of trans fat over many years boosts the heart disease risk by 25 per cent. Trans fats may also affect brain development in children.

According to the National Review of Medicine, Canadian consumption of trans fats is among the highest in the world. "Health Canada statistics indicate that people in the 15-25 age group consume an average 38g a day. The World Health Organization suggests limiting trans fats to less than 3g a day."

CTV and The Globe and Mail decided to test some fast foods to see how much of this dangerous trans fat consumers are gulping down in take-out meals.

The study tested similar meals from four chains, at locations in Toronto and Vancouver:

• The KFC meal contained had the highest levels of trans: A whopping 18.6 grams. At that level, if eaten daily, it could boost the risk heart disease, by almost 100 per cent.
• The Burger King  meal wasn't far behind at  13 grams of trans.
• Wendy's meal had just over 5 grams, lower but at a level that if consumed daily, increases your risk of heart disease by 25 per cent.
• The lowest levels were found in the McDonald's meal with just under two grams ( 1.8 grams) of trans for their entire Chicken McNuggets and fries meal.

Here are the charts from CTV's tests:

KFC Results

* Note: The results were conducted on french fries and chicken nuggets from a childrens' meal.

* Note: The results were conducted on french fries and chicken nuggets from a childrens' meal.

* Note: The results were conducted on french fries and chicken nuggets from a childrens' meal.

McDonald's Results

* Note: The results were conducted on french fries and chicken nuggets from a childrens' meal.