So which breakfast is the best?

Last week it was revealed that having breakfast can significantly reduce your susceptibility to colds and flu. Researchers at Cardiff University found that of 500 volunteers studied over 10 weeks, the ones that had skipped the first meal of the day were much more likely to contract an illness.

But can it be any old breakfast? We asked dietician Sarah Schenker, of the British Nutrition Foundation, to look at the typical London morning starter and say which will properly set you up for the day, and which is just a false dawn.

The crunch

Bowl of cereal. If you don't succumb to the urge for sugar to keep you going in that first meeting, this will do more good than harm. Cereals are usually low in fat and high in carbohydrates, a great source of energy for the morning. Most are, as the packet says: "fortified with extra vitamins and minerals". Iron is important for healthy blood and B vitamins are important for energy metabolism. If they are high in fibre they keep you feeling fuller for longer. The milk added to cereal provides protein; semi-skimmed is the best provider of calcium for healthy teeth and bones. A glass of orange juice would provide vitamin C to help with the absorption of the added iron. 7/10

The Continental

Croissant and cappuccino. Chic it may be, but this breakfast provides quite a lot of fat and not much substance, meaning you will run out of steam very quickly. A croissant does not provide any protein and isn't a particularly good source of vitamins and minerals; calcium is provided from the milk in the cappuccino, but the milk is usually full fat. The caffeine will give you a boost, but too much caffeine is a diuretic that can leave you dehydrated and less able to concentrate. Adding a glass of juice or a piece of fruit would help. 4/10

The best of British

Full English breakfast with tea. Despite the caff image, there are many worse ways to start the day. Depending on what you have and how it has been cooked, this can provide lots of protein, vitamins and minerals. Beware saturated fat, which can increase blood cholesterol levels dramatically. Choose lean, rindless bacon, low-fat sausages (both provide protein, iron and zinc), grilled tomatoes, poached eggs (good source of vitamin A) and toast. Try to avoid frying anything to keep the fat down. Accompany with a glass of milk to provide some calcium. 6/10 - but 9/10 if you lose the fat

Savoury snack

Toast, Marmite, cup of tea. Increasingly trendy starter-togo for the time-famished. Bread is an excellent source of carbohydrate for energy - if it's wholemeal, the fibre will keep you feeling full. Marmite is an excellent source of vitamin B, as well as being fatfree and low in sugar. Tea is a good source of antioxidants - currently being investigated for possible benefits to the heart. A low-fat cream cheese on the toast instead of butter reduces the fat content and provides calcium. 8/10

Fruit appeal

Orange juice and banana. This will get you into the office feeling virtuous, but won't keep you going after the first couple of photocopies - and if you are doing something physical, forget it. While it is a good source of vitamin C (juice), and the banana gives you carbohydrate energy, there is no staying power here. Add a bowl of cereal, at the very least. 7/10

The false start

Black espresso and a cigarette. The nutritionist's nightmare: it provides no energy, no nutrients, the caffeine will give you a kick, and the cigarette will suppress the desire for food, but by 10 o'clock you'll be starving and if you have more coffee and cigarettes to counter this, you'll be caught in a vicious and potentially deadly spiral. 0/10

The good life breakfast

Yoghurt and apple. Not as good as it looks. The yoghurt provides protein and calcium and is low in fat, while the apple will help fill you up because it is high in fibre, but many people don't realise that they start the day slightly dehydrated because they don't drink enough. This can affect their ability to concentrate at work making them feel restless and irritable. A large glass of water or fruit juice would be a good addition. 7/10

Snap but no crackle

Breakfast cereal bar. A mouthful on the way to the Tube is better than skipping breakfast altogether - but only just. The packet trumpets the fact that these are fortified with extra vitamins and minerals, even calcium. But the calcium would probably be better absorbed from milk. Not very filling, and you will probably find you need to eat again soon after. Add some fruit juice. 4/10