ITV News science correspondent Alok Jha reports:
New research has found that advice issued over 30 years ago advising people to avoid eating fatty foods should "not have been introduced."
Experts say the recommendations around dairy fat were not backed up by scientific evidence and should never have been issued.
Tens of millions of people were warned that fat consumption should be strictly limited to cut the risk of heart disease and death.
However, placing the emphasis on saturated fats, experts warn, means public heath teams have not given enough attention to other obesity risks, such as carbohydrates.
The research paper, which reviewed data available at the time the guidelines were issued says:
The paper, published in the online journal Open Heart, added: "Dietary advice not merely needs review; it should not have been introduced."
But in a linked editorial, Rahul Bahl, of the Royal Berkshire NHS Foundation Trust, sounded a note of caution.