Kiwi consumers are still in the dark about some harmful ingredients in packaged foods

Across the world, diets high in trans-fats kill 645,000 people each year.

New Auckland University research reveals trans-fats in many foods aren't disclosed.

Population health senior research fellow, Kathryn Bradbury, says it's almost impossible to tell which products include them.

She says food products have to say how much energy, protein, carbohydrates and total fat they contain, but not trans-fats.