Food labels should list "hidden" fats to help reduce coronary heart disease, according to scientists.
Margarine contains trans fats
Trans fats, the solid fats found in some processed foods, boost "bad" cholesterol levels, increasing the risk of heart disease.
The Oxford team says labelling trans fats content, as well as saturated fats and cholesterol, will enable consumers to make healthier food choices.
The article is published in the British Medical Journal.
They are partially hydrogenated vegetable oils, turning oily foods into semi-solid foods
Used to extend shelf life of products
Put into pastries, cakes, margarine and some fast foods
Can raise levels of 'bad' cholesterol
Even a small reduction in consumption can cut heart disease
They have no nutritional benefit
Trans fats, also called trans fatty acids, occur naturally in small amounts in dairy products and meat, but are also formed by a process called partial hydrogenation, which is used to extend the shelf-life of processed food.
They can be found in margarines, biscuits, cakes and fast foods.
The authors, from the University of Oxford, point to recent US research that revealed a 2% increase in the energy intake from trans fats was associated with a 23% rise in the occurrence of coronary heart disease.
The Oxford researchers have concluded that consumers should be able to see the amount of trans fats in their foods.
Dr Robert Clarke, honorary consultant in public health at the University of Oxford, said: "It is difficult for the layman to make informed choices about what he or she eats if they do not know what is in their food."
In the UK, the nutritional information posted on food labels is at the discretion of the food manufacturer, unless a specific nutrition claim, such as "low in trans fats", is made.
Most choose to provide some data, and some companies list the level of trans fats, including Sainsbury's, Nestle and Unilever.
A review of an EU directive that governs the content and format of nutrition labels is under way, and this may change the current regulations.
But Dr Clarke said: "Experts feel this discussion is getting nowhere."
He suggested the UK undertakes a similar approach to labelling fats as the US Food and Drug Administration's scheme, implemented in 2006.
He said: "The American model of including the saturated fat content, the trans fats content and the dietary cholesterol level seems appropriate and allows the consumer to make a choice about what they eat.
"It is all about trying to introduce a change that affects a minority of foods that could have a significant impact on the LDL cholesterol, which in turn influences risk of heart disease."
'No nutritional value'
A spokesman from the Food Standards Agency said: "The agency recognises the need to improve the labelling of trans fats in foods and is pressing for changes at European level when the Commission publishes a new proposal."
Dr Mike Knapton, of the British Heart Foundation, said countries such as Denmark had banned the use of trans fats in products without any discernable impact on the consumer.
"Given that they are bad for you, we can replace them, and they have no nutritional benefit, it seems sensible to try to give the public information about which foods contain trans fats.
"There is no need to have trans fats in our diet at all."
A spokesman from the Food and Drink Federation said: "Consumers can be reassured that food manufacturers are already cutting trans fats in food.
"Manufacturers are fully committed to reducing the level of trans fats to as low as is technically possible."