Take food labels with a pinch of salt

At a time of global poverty and famine, there is a tragi-comic irony at the spectacle of Western grown-ups having to be taught to eat less. But appetite and abundance have rendered us ignorant.

At the Pritikin Longevity Centre in Florida, building mental as well as bodily muscle is the mission. To this end, once a week, Pritikin ushers its clients through a local restaurant to show them how to healthily negotiate a calorie-dense, salt-rich menu.

The rules are: start meals with a salad (bring your own dressing); ask about preparation methods and request no added oils, butter, cream, salt or sugar; divide a main course dish between two and add two vegetable side dishes; talk to the manager and let him or her know your needs.

(In my own London dining experience at Giraffe, a breakfast place in Hampstead where for the last eight years I have met

twice a week with two other health-conscious mates, using our total yearly spending there as a bargaining chip, we lobbied successfully to have steel-cut oatmeal put on the otherwise calorie dense menu.)

Pritikin also marches interested clients through a local whole food supermarket to teach them both how to read food labels and how to choose the healthiest option. (In Britain, the labelling is even smaller and more confounding.)

Pritikin admonishes its clients never to believe the front of any package, covered as they are with weasel words such as 'enriched', 'all natural', 'fat-free, 'baked' and 'seven-grain'. The key is knowing how to decode the nutritional facts on the label of contents. This is a quick calculation: the proportion of fat should never be more than 20g per 100g; the sodium should be 0.1g per 100g; check to see if sugar, or derivatives like corn syrup and fructose, are among the first three to five ingredients; if so, avoid the product.

On my whirlwind trip through the store,