Fatty foods that have not been processed -- such as butter, cheese, eggs and yogurt -- can even be good for the heart, and repeated advice that consumers should cut their fat intake may have actually increased risks of heart disease, said Dr Aseem Malhotra.

Writing in the British Medical Journal, he argues that saturated fats have been “demonized” since a major study in 1970 linked increased levels of heart disease with high cholesterol and high saturated fat intake.

The NHS currently recommends that the average man should eat no more than 30g of saturated fat a day and women no more than 20g. However, Malhotra, a specialist at Croydon University Hospital, said that cutting sugar out of the diet should be a far greater priority.

He said, “From the analysis of the independent evidence that I have done, saturated fat from non-processed food is not harmful and probably beneficial. Butter, cheese, yogurt and eggs are generally healthy and not detrimental.

"The food industry has profited from the low-fat mantra for decades, because foods that are marketed as low-fat are often loaded with sugar. We are now learning that added sugar in food is driving the obesity epidemic and the rise in diabetes and cardiovascular disease.”

A recent study indicated that 75% of acute heart attack patients have normal cholesterol concentrations, suggesting that cholesterol levels are not the real problem, Malhotra argued.

He also pointed to figures suggesting the amount of fat consumed in the U.S. has gone down in the past 30 years while obesity rates have risen.

Bad diet advice has also led to millions of patients being prescribed statins to control their blood pressure, he argues, when simply adopting a Mediterranean diet might be more effective.

However, Professor Peter Weissberg, medical director at the British Heart Foundation, said, “Studies on the link between diet and disease frequently produce conflicting results because, unlike drug trials, it’s very difficult to undertake a properly controlled, randomised study.

"However, people with highest cholesterol levels are at highest risk of a heart attack.