Teaching in January. It’s cold, it’s dark, and you are permanently hungry.

You have also put on a few pounds over Christmas. There is no time for breakfast, so you grab a banana and an apple and leave the house. You wolf the banana and start teaching. Then break comes and the flapjack in the school canteen looks irresistible. Somehow, the apple would not hit the spot... and so it goes on.

What you need in winter is fuel, to keep you mentally and physically alert.

And the best kind of fuel is slow-burning. Any teacher can pick out the inattentive or lethargic pupils who have missed breakfast or snacked only on sugary or fatty foods. To cope with them, teachers need food that will keep them going all day.

The good news is that this energy is best provided by starchy carbohydrates. As Kathy Cowbrough, a nutritionist, says, these are foods that release their energy slowly, so they should form the basis of both your breakfast and lunch.

“Bread and rolls are great,” she says. “Think of all the different sizes, shapes and flavours. Make some of them wholegrain. And if you want a change from bread try wraps, chapatti, pitta or bagels. There is also rice, pasta, couscous and potatoes.”

The even better news is that it’s a myth that starchy foods are fattening.

In fact, carbohydrates give you only half as many calories as fats. “It’s often what you put with these foods that adds the calories, and not the foods themselves,” says Kathy. So what should you put with them? “A bit of protein, from fish, lean meat, dairy products, eggs, nuts or pulses,” she says.

“Then you need to think vegetables and fruits. It doesn’t always have to be apples, oranges and bananas - try kiwi, mango, grapes, melon chunks or fruits in season such as plums. Or vary it with dried fruits or tinned fruit in juice.”

“Remember, there is no one food that is bad for you,” says Kathy. “The important thing is to get the balance of foods right: lots of starchy carbohydrates, fruits and vegetables and a bit of protein. If you do that, you can allow yourself the occasional fatty or sugary “treat” such as a packet of crisps or slice of flapjack”

Kathy Cowbrough is a state registered dietician and an adviser to the British Heart Foundation

Healthy eating tips

Start the day with a good breakfast, even an egg (eggs don’t boost bad cholesterol). But, if you don’t think you can manage as much as a bowl of cereal, take something simple to eat and drink to avoid the mid-morning slump, such as fruit or a cereal bar.

Drink water or fruit juice (but not squash or fruit drinks), semi-skimmed milk or yoghurt drinks.

Try not to skip meals because of lack of time or because you want to lose weight. It’s actually easier to take in more calories that way because you’re not conscious of how much food and drink you snack on during the day. And you’ll tend to snack on foods that are fatty and sugary, with little nutritional value.

Putting it all together

If you don’t want to eat lunch in the school canteen, try putting together a healthy but filling alternative:

A wrap or chapatti spread with low calorie cream cheese, raw (or leftover) vegetables and a little grated cheese - or with baked beans, lettuce, chopped tomato and a dab of yoghurt or sour cream.

Crackers, oatcakes or rice cakes with thin slices of cheese, ham, chicken or turkey, hard-boiled eggs, cherry tomatoes and cucumber sticks.

Pasta with leftover grilled sausages, tomato sauce and green peppers.

Cooked rice mixed with leftover curry or mixed vegetables.

Couscous with raisins, chopped apple and tuna or mackerel with a light mayonnaise and mixed herbs.

Thick vegetable or lentil soup to reheat at school, with a piece of bread.

And, if you get hungry mid-morning or mid-afternoon, take chopped vegetables with a dip, raisins, nuts, fruit, yoghurt - or a teacake or scone.

Visit www.food.gov.uk and www.nutrition.org.uk