Children in Italy, Greece and Spain are now the fattest in Europe. More than 40% of boys and girls aged nine are either overweight or obese. Sweets,junk food and sugary drinks have displaced the region’s traditional diet based on fruit and vegetables, fish and olive oil. (World Health Organisation)

One study suggests that your bank balance is the important factor. Researchers at the Mediterranean Neurological Institute in Italy, who carried out a study of more than 18,000 men and women over four years, found a 15 per cent reduction in cardiovascular risk for those on the Mediterranean diet, but only if they earned £35,000 a year or more. For the less advantaged, the benefits of the diet weren’t seen at all.

Even though all study participants followed the Mediterranean diet, those with higher incomes tended to eat food that had more heart-protecting antioxidants and polyphenols, and which was grown with fewer pesticides. Those with lower incomes had less access to a wide variety of fruits, vegetables and whole grains, and tended to buy foods that had lower nutritional value (International Journal of Epidemiology, doi.org/cbhh).

“The real extra virgin olive oil that was used in the Predimed trial is about 8 euros per bottle,” says Marialaura Bonaccio at the Mediterranean Neurological Institute. “So the question is, do I get the same benefits from a bottle of olive oil that costs 10 euros, as compared to the lower quality one that I paid 2 euros for?” She suspects that the difference in benefits may come down to higher quality foods that cost far more. “It’s a real paradox. When the Mediterranean diet was discovered, it was the diet of the poorest people in Italy and Greece. Now, it’s the diet of the rich people,” she says.

By the way, the World Cancer Research Fund is warning that as many as 12 different kinds of cancer are now linked to being overweight. It has launched an online tool to help people assess the risk posed by their diet and lifestyle.

All this sounds very familiar: health linked to income. Many people think that obesity is a matter of choice and no business of anyone else’s. Well, it is actually. Aside from anything else it increases national health costs for everyone, rich and poor. But it also reduces the quality of life and its length for poorer people. Not much point in championing the interests of the less well off if you are also indifferent to their health and longevity.