TORONTO - Ontario's Liberal government will introduce legislation Wednesday to ban trans fats in school cafeterias and take steps towards banning junk food in high schools.

Premier Dalton McGuinty says trans fat, which is often found in french fries and other cafeteria staples, can contribute to childhood obesity.

He says kids aren't as healthy as they used to be, so the government will eliminate the sale of foods containing trans fats in elementary and secondary schools.

Chocolate bars, potato chips and soft drinks have already been eliminated from elementary schools, but McGuinty says he wants to see that expanded to high schools.

Education Minister Kathleen Wynne says school cafeterias will be required to follow the Canada Food Guide with their menus.

But Wynne admits it could take some time to get junk food out of high school vending machines because she doesn't want to see schools fined for breaking existing contracts.