Guidelines warning people to avoid eating fatty foods such as butter and cheese "should not have been introduced", new research has found.
Dietary advice issued to tens of millions had warned that fat consumption should be strictly limited to cut the risk of heart disease and death.
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But experts say the recommendations, which have been followed for the past 30 years, were not backed up by scientific evidence and should not have been issued.
Resaearchers say in a paper, published in the online journal Open Heart, that: "Dietary advice not merely needs review; it should not have been introduced."
The guidelines, implemented in the UK in 1983 and in the US six years earlier, recommended reducing overall dietary fat consumption to 30 per cent of total energy intake and saturated fat to 10 per cent.
But researchers say the guidelines "lacked any solid trial evidence to back it".
Experts warned that in characterising saturated fat as the "main dietary villain", public health teams have not paid enough attention to other risks - especially carbohydrates which are believed to be helping to fuel the obesity crisis.
- PAA