"Hidden" fats which have been linked to heart disease are being cut from around £1.5bn worth of foods, an industry body has said.
Margarines are one of the foods which contain trans fats
Trans fats, made from vegetable oil and used in processed foods, have been linked to raised cholesterol.
The Food and Drink Federation has said hundreds of well-known brands, such as Horlicks, Mars and Weetabix, are being reformulated to eliminate trans fats.
Heart experts called for food labels to list trans fats levels.
The FDF polled 20 top food and drink manufacturers, asking about their position on trans fats.
Of those, 11 companies came back with details while the other nine either had no trans fats in their products or did not release details.
Based on these responses, the FDF has put a retail value of £1.5 billion on the products being reformulated.
Julian Hunt of the FDF said many companies had "dramatically" cut trans fats over the past two years.
"The industry is committed to reducing the level of trans fats to as low as is technically possible and has been actively reducing these levels.
A report in the British Medical Journal published earlier this year called for trans fat content levels to be shown on product labels.
Alex Callaghan of the British Heart Foundation said: "It's good to see some food manufacturers and retailers committing to reducing trans fats from their products.
"But until they are completely removed we can only take manufacturers' word for it that these levels are being reduced, since most continue to refuse to label trans fats on their products."
The BHF said it wants the listing of trans fat levels on food labels to be made compulsory.