Bread 'n' butter issues of a healthy diet...
Where do we begin with the spaghetti-like mess that is the supposed link between illnesses such as coronary heart disease and diet?
Yet another study appears to have overturned previous advice on cutting down on butter, eggs, red meat and other food containing saturated fats.
Remember the days when margarine was touted as a safer alternative to butter? Well, that's another myth destroyed by the latest research showing that trans-fats, rather than saturated fats, are the real killers lurking in the fridge.
Some of us have blamed Ancel Keys, the American physiologist who, half-a-century ago, claimed to have established a link between heart disease and saturated fats.
The idea was that, by cutting down on dietary intake of saturated fats, you lower cholesterol levels in the bloodstream and so reduce the build-up of fatty deposits in the blood vessels to the heart.
But the link between heart disease and cholesterol in the bloodstream - which is not the same as cholesterol in the diet - is firmly established.
So are the proven beneficial effects of a Mediterranean diet rich in middle-class delicacies, such as olive oil and fatty fish, which, incidentally, we can thank Ancel Keys for discovering.
No one, it seems, now disputes the tragic error of introducing trans-fats, made by the industrial hydrogenation of vegetable oil, into the diet. They were supposed to have been removed from the UK food chain 10 years ago.
But the real question is, what should we make of the failure to find a link between relatively small quantities of saturated fats in the diet and coronary heart disease?
I asked Russell de Souza, the lead author of the latest study, whether we have been led astray with previous advice on avoiding saturated fats in the diet.
"I don't think so. With any single food item, too much may be a bad thing," Dr de Souza replied. "Remember that foods like butter, eggs and bacon contain not only saturated fat, but also other ingredients that may help or harm.
"Eating too much red, or processed, meat may increase one's risk of other diseases - notably cancer and diabetes."
So, if you are confused, just stick to fresh fruit and vegetables, fish drizzled in olive oil, wholegrain bread, a little cheese and a glass or two of red wine.