Dietary advice warning people to avoid eating fatty foods such as butter and cheese "should not have been introduced," according to new research led by the University of West Scotland.
The guidelines, which have been followed for the past 30 years, warned that fat consumption should be strictly limited to reduce the risk of heart disease and death.
But experts say this was not backed up by scientific evidence and the advice should never have been released.
It recommended reducing overall dietary fat consumption to 30% of total energy intake and saturated fat to 10%.
The guidelines, which were introduced in the UK in 1983 and in the US in 1977, "lacked any solid trial evidence to back it," researchers say.
Experts said that the advice characterised saturated fat as the "main dietary villain".
As a result, public health teams have not paid enough attention to other risks, such as carbohydrates, which are believed to be fuelling the current obesity crisis.
Research
The comments are contained in a research paper which reviewed the data available at the time the guidelines were issued.
The paper, which appears in the online journal Open Heart, states: "It seems incomprehensible that dietary advice was introduced for 220 million Americans and 56 million UK citizens, given the contrary results from a small number of unhealthy men.
"The results of the present meta-analysis support the hypothesis that the available (randomised controlled trials) did not support the introduction of dietary fat recommendations in order to reduce (coronary heart disease) risk or related mortality."
The paper added: "Dietary advice not merely needs review; it should not have been introduced."
However, Rahul Bahl, of the Royal Berkshire NHS Foundation Trust, sounded a note of caution on the issue.
In a linked editorial, he wrote: "There is certainly a strong argument that an over-reliance in public health on saturated fat as the main dietary villain for cardiovascular disease has distracted from the risks posed by other nutrients, such as carbohydrates.
"Yet replacing one caricature with another does not feel like a solution."
Dr Alison Tedstone, chief nutritionist at Public Health England, said: "This paper is not critical of current advice on saturated fats but suggests that the advice was introduced prematurely in the 1980s before there was the extensive evidence base that exists today.
"The advice issued by COMA (Committee on Medical Aspects of Food Policy) in 1991 confirmed that eating too much saturated fat can raise cholesterol levels, which increases the risk of heart disease."
The Irish Heart Foundation insists we are still at less risk of heart disease when we cut down on saturated fats.
Around 10,000 people die in Ireland every year as a result of cardiovascular disease.
Originally published at 7.30am
