is it healthy or a meringue?

Yes, we're talking about Andy Cameron's legendary joke: "Is that a doughnut or a meringue? No, you're right. It's a doughnut."

I like Andy's joke so much I use it often in Barcelona pastelerias (cake shops to youse) where I point to a large white confection and ask: "Es que este es un donut o un merengue?" The answer is: "Claro, es un merengue."

If you are going to buy a meringue in Barcelona, I recommend the pasteleria next to the Jaume 1 metro station. They are the size of a small Pyrenean peak with the chewiest and tastiest mallow centre.

A slight problem is that eating a meringue in Barcelona can be perceived as treason or at least disloyalty. Merengue is a nickname for Real Madrid (because of the all-white strip) and many a Barca fan would not eat one if they were paid to do so. They might if meringues came in the blue and crimson colours of their team.

But I have digressed. You probably want to know the science of why egg whites are good for you. They contain a peptide which acts as an angiotensin-converting-enzyme inhibitor which keeps the blood healthier.

Egg white also provides 10% of your daily need for selenium. The cream of tartar in meringues gives 14% of your daily potassium. A bit like Guinness being full of iron and trace elements.

Don't forget all that vitamin C in a lemon meringue pie. Or the five-a-day berries that often come with a meringue dessert.

At this point spoilsports will point out that meringue is full of deadly sugar. You could always try moderation with one meringue a month.

Or bake them with artificial sweeteners. Other spoilsports will say that chemical sugar substitutes are more dangerous that the real thing. As a diabetic, I have no choice. As Sandie Shaw sang: "You'll always be Aspartame (whoa-ooo-oh-oh)."

Apparently, if meringues are made with slightly healthier unrefined brown sugar they taste like toffee. Which seems an acceptable compromise.