Why trans-fats might be in foods you do not expect

Trans-fats are unsafe to eat and must be banned from the food supply within three years, US regulators have said.

The US Food and Drug Administration said partially hydrogenated oils (PHOs), the main source of trans-fats, are not "generally recognised as safe".

But what are trans-fats and where do they still exist in the US food supply?

Jane O'Brien reports

Filmed and edited by David Botti