Time was that conflicting nutritional advice was issued at decent intervals, to give us time to adjust. A respectable number of years, for example, passed between "Go to work on an egg" and "Don't eat eggs". These days foods shuttle between the Good and Bad columns with such haste that they sometimes seem to inhabit both at once. So what should you eat, or not eat, at this exact moment in space-time? Below, a snapshot of what is currently on and off the menu.
Nuts. Very good for you, according to a brand new study, which found that eating them regularly reduces the risk of a heart attack by as much as 11%, probably thanks to their high proportion of monounsaturated fatty acids. This applies to most kinds of nuts, including walnuts, cashews, brazil nuts and peanuts, even though peanuts are not, strictly speaking, nuts. Of course the beneficial effect is mitigated if your daily portion of peanuts comes encased in a Snickers bar.
Wine. Also good, says professor Alan Crozier of Glasgow University, claiming that two or three glasses of red wine a day will protect arteries. Three glasses is, of course, also the upper recommended safe daily limit for women, while two glasses is still, for many of us, nothing like enough. "High alcohol intakes have been linked to a number of cancers," says Lisa Miles of the British Nutrition Foundation.
Chocolate. This contains flavonoids, which may lower the risk of heart attacks by thinning the blood. However, says Miles, "any potential benefits should be considered carefully as chocolate, and products containing it, often contain relatively high amounts of fat and sugar". And it rots your teeth. Still, a little chocolate from time to time can't hurt you. Unless you're a dog.
Margarine. Long sold as a healthy, if unworthy, butter substitute, margarine can contain trans fatty acids produced by the hydrogenation of vegetable oils. And trans fatty acids, as everybody knows, are the newest hate-fat. Apparently it's not such a big deal in this case, however. "Efforts have been made in the UK to reduce or even remove trans fatty acids from margarine and spreads," says Miles.
Eggs. Once hailed for their mineral and protein content, and then vilified for their cholesterol content. Now, it seems, we're back where we started: "Although eggs contain cholesterol it is now known that cholesterol from our diet has little influence on blood cholesterol concentrations in healthy individuals," says Miles. So there you have it: eat as many eggs as you like, just don't eat them raw.
Fried Coke. There is little hard nutritional information on Fried Coke, only recently unveiled at the Texas state fair. It consists of Coca-Cola-flavoured, deep-fried batter, covered in Coke syrup, sugar and whipped cream. It sounds as if someone invented the most unhealthy snack imaginable, and then accidentally tipped his drink into it. But let's not be judgmental: it may turn out to be a cure for something.