Government health chiefs recommend eating five portions of fruit and vegetables a day as research has shown they can help reduce the risk of cancer and coronary heart disease, which together account for 60 per cent of premature deaths.

Fruit and vegetables provide essential vitamins, minerals, fibre and antioxidants and as they are low fat, low calorie foods they are ideal for helping people achieve and maintain a healthy weight.

The portions can come from fresh, frozen and canned fruit and veg, although the canning process destroys some nutrients –– and even fruit juices and dried fruit can count towards your daily total.

Each portion, for a person of average build and reasonable activity level, should be about 80g of fresh vegetable or fruit, which is equal to one apple, a medium banana, 12 chunks of canned pineapple or a handful of raw vegetable sticks.

Health chiefs recommend having a varied diet as different fruit and vegetables contain different combinations of fibre, vitamins and minerals and only one daily portion should come from juices or smoothies as the juicing process reduces fibre and releases fruit sugars.

Dried fruit should count as only one portion a day because the sugar content is much more concentrated and pulses, such as beans and lentils, should only count as one daily portion as they do not contain the same mixture of nutrients as fruit and vegetables.

And as the Government's Five a Day scheme encourages food manufacturers to promote healthy eating by using portion indicators on packaging it is becoming easier to keep an eye on how much you are eating.

Be careful to make sure it is the government logo, a series of five coloured squares ascending from left to right, as some manufacturers and retailers have introduced their own schemes and these do not always tie in with government advice.