Lunchbox

Jody Ward, 28, a policewoman, ate a jacket potato with tuna mayonnaise and a large salad, followed by an apple, and drank a Diet Coke.

"The nature of my job means I have to eat while I can," says Jody. "I spend long hours at work and am often limited by the meals provided by the work canteen, but I do try to eat healthily whenever I can. I also do a lot of exercise, so I need to eat regularly."

Juliette Kellow, a state-registered dietician and deputy editor of Slimming magazine, says that such a meal would give Jody 685 calories. Of these, 21 per cent comes from protein, 48 per cent from carbohydrate and 32 per cent from fat, of which 5 per cent is saturates.

"This is a well-balanced meal which is low in sugar and high in starchy carbohydrates and fibre - a perfect example of how healthy eating recommendations can be put into practice," says Juliette. "The meal is also packed with vitamins and minerals, which are needed for good health.

"Having a good intake of starchy foods is especially important if you do a lot of exercise or have a particularly active job. This is because starchy carbohydrates provide the body with a slow, steady supply of energy rather than the sudden, short burst which you get when you have lots of sugary foods. Consequently, it's a lot better to have a sandwich or a piece of toast than a bar of chocolate before you take exercise. It's also important to take in plenty of fluids if you are going to be very active; water is best.

"The fibre content of this meal is really good, with most being provided by the jacket potato, the apple and the salad. As well as being useful in preventing constipation and keeping the bowels healthy, fibre-rich foods help to fill you up. This will prevent you from feeling hungry between meals, which may lead to snacking on fatty and sugary foods.

"All in all, this is an excellent meal, which shows how easy it can be to choose a healthy lunch even when you have to rely on a canteen."

Glenda Cooper