'We've been sold a big fat lie'

New research suggests that official warnings against consuming saturated fats like those in butter and full-fat milk are based on flawed evidence.

An article in the British Medical Journal's Open Heart publication argues that dietary guidelines adopted in the early 1980s and still in use today are based on "very limited evidence".

The British Dietetic Association recommends that men should consume no more than 30g of saturated fat daily and women no more than 20g.

But the report's authors, led by University of the West of Scotland researcher Zoë Harcombe, show that women were excluded from trials and risks of saturated fats were never proven.

"It seems incomprehensible that dietary advice was introduced for 220million Americans and 56million UK citizens given the contrary results from a small number of unhealthy men," argue the report's authors.

But Tom Sanders, professor of nutrition and dietetics at King's College London, said current dietary recommendations should not be changed on the basis of shortcomings in historical trials.

"Their conclusion fails to take into account the totality of the evidence. Different types of evidence are available," he said.

But leading cardiologist Dr Aseem Malhotra said: "Cutting out sugar and white bread is better for your weight and heart."