New research suggests advice to avoid eating fatty foods was not backed up by science and should not have been introduced 30 years ago.
If nutrition experts are set for a U-turn on fat, it would hardly be the first time that dietary and medical tips should have come with their own health warning.
:: Cigarettes
In the 1930s and 40s, before the dangers of cigarettes were well known, many doctors were enthusiastic smokers.
Advertisers were keen to make use of this, with the biggest brands battling it out to be the "healthiest" choice.
US public health researchers believe American Tobacco was the first firm to use doctors in advertising.
A typical poster from 1930 featuring a white-coated medic brandishing a pack of Lucky Strike and the claim "20,679 physicians say Luckies are less irritating".
In 1946, RJ Reynolds built a campaign on the slogan, "More doctors smoke Camels than any other cigarette".
Now, of course, the potentially devastating consequences are undisputed, with almost six million deaths a year attributed to smoking, according to the World Health Organisation.
:: Eggs
Edwina Currie angered farmers with her 1988 salmonella claim
Not so long ago, official advice told us we should eat no more than two eggs a week as they contained heart-stopping cholesterol.
The egg industry famously suffered a further blow in 1988, when health minister Edwina Currie declared that "most" of Britain's egg production was infected with potentially lethal salmonella bacteria.
She resigned two weeks later amid an avalanche of writs from the farming industry and the Government was forced to offer millions of pounds in compensation as egg sales plummeted.
Recent research has shown that cholesterol in eggs has almost no impact on blood cholesterol, suggesting fears of a link to heart attacks are unfounded.
In fact, eggs are highly nutritious - a great source of protein and all the main vitamins except C.
:: Milk
Michelle Obama convinces schoolchildren of the benefits of drinking milk
Conventional wisdom suggests that switching from whole milk to semi-skimmed or even skimmed is one of the easiest steps towards a healthier lifestyle.
But the benefits of switching from full fat milk may have been greatly exaggerated.
Foods with a fat content of more than 20% are considered high fat, but cow's milk usually contains no more than 5% fat per 100ml.
Semi-skimmed has around 1.5% and skimmed 0.1% - but they lack the nutritional value of whole milk - which contains fat soluble vitamins A, D, E and K and keeps bones healthy while helping protect against infections.
:: Coffee
A cup of coffee could help prevent some cancers, researchers say
Caffeine is often one of the first things to go when someone announces they are on a health kick.
The idea that coffee could be dangerous stems mainly from studies in the 70s and 80s that linked the drink to higher rates of cancer and heart disease.
Scientists now believe that earlier studies may not have taken account of other unhealthy lifestyle choices and habits of volunteers, such as smoking.
Researchers at Harvard University last year released findings from a study of around 130,000 people, which suggested drinking up to six cups of coffee a day could be perfectly safe.
It found no increased risk of death from any cause, including cancer or heart disease, while other studies have indicated that coffee could help protect against some cancers, diabetes and Parkinson's disease.
The Harvard academics did warn that pregnant women and those who have trouble controlling blood pressure or blood sugar may still want to cut their caffeine intake.
:: Artificial Sweeteners
Drinks containing artificial sweeteners may not be much healthier
With sugar the latest health bogeyman, many of us are replacing it with artificial sweeteners, while many low calorie foods also contain sugar substitutes.
But some studies have suggested that artificial sweeteners can actually cause us to pile on the pounds.
The theory is that when denied the calories that should come with sweet food, our body tells us to go looking for them elsewhere, making bingeing and snacking more likely.
