This is our main source of energy, and comes in three types: simple sugars, complex carbohydrates (or starches) and dietary fibre. We teenagers need slightly more carbohydrate than adults because our energy needs are greater. Between 50–70% of the energy we obtain should come from complex carbohydrates.

• Simple sugars are things like fruit, milk, and ordinary sugar.
• Complex carbohydrates are cereals, grains, and some root vegetables such as potatoes.
• Dietary fibre includes wholemeal bread and brown rice but it also comes in fruit and vegetables.

Protein is essential for growth, repair and reproduction. Teenage girls need about 45g of protein every day (more if pregnant, breastfeeding or very active). Boys need about 55g (more if very active, less if not breast-feeding or pregnant ha ha!). In Western countries most people eat more protein than they really need since many foods are very rich in it.
Protein comes in lots of different foods, for example: meat, fish, nuts, seeds, pulses (beans, peas, lentils), grains/cereals (wheat in bread, pasta etc, oats, rye, rice), dairy products, Soya products, free-range eggs.

Fat is another rich source of energy. Too much fat is bad for us, but a little is necessary to keep our tissues in good repair, for the manufacture of hormones and to act as a carrier for some vitamins.

Fats can be found in milk, cheese and other dairy products, as well as oily fish and meat. They can be found in two different forms, either saturated (animal fats) or unsaturated (vegetable fats). Unsaturated fats being better for you as they are less likely to increase your blood cholesterol level which is linked to heart disease.

Vitamins are vital for growth and development and the functioning of your body's cells. There are many different types of vitamins that our body needs, here listed are the most important ones that we need in our diet.

Vitamin A - This is important for eye health. As it protects the cornea. It's also vital for bones, growth and reproduction, as well as helping you resist infection. On top of all that it keeps your skin and hair healthy.
Vitamin A deficiency can cause all kinds of symptoms, including sore eyes, dry hair, and dry skin, weak bones and weak teeth.

Where can I find it? - Liver and fish liver oils, egg yolk and dairy products are good sources. Beta-carotene, which protects the body against disease and premature ageing, is converted to Vitamin A by the body. It's found in spinach, carrots and apricots.

Vitamin C (ascorbic acid) - Vitamin C (ascorbic acid) can help fight the common cold. It also helps the body resist infection and improves absorption of iron. Vitamin C keeps your teeth and gums healthy and boosts your bones and muscles. You can easily get enough Vitamin C, but various things increase the need for it. These include smoking, serious injury or burns, and oral contraceptives. Vitamin C deficiency, like iron deficiency, can lead to anaemia. Another symptom is bleeding or tender gums.

Where can I find it? - Eat plenty of fresh fruit and vegetables and you can't go wrong.

Vitamin D - Vitamin D helps your body absorb calcium and other minerals, which makes for strong teeth and a healthy nervous system. If you're short of Vitamin D it can lead to softening of the bones and teeth, nervousness and insomnia. Severe Vitamin D deficiency sometimes causes rickets.

Where can I find it? - It's sometimes known as the 'sunshine vitamin' as we make our own Vitamin D when the skin is exposed to sunlight. In terms of food, you find it in milk, cheese and fatty fish like herring and mackerel.

Folic acid - Folic acid is essential for all kinds of enzyme activities. If you are pregnant you must make sure you have enough folic acid in your diet, as it appears to protect against some birth defects. Drinking a lot of alcohol or taking oral contraceptives can increase your need for folic acid. Other drugs, such as aspirins, can also hamper its absorption. Folic acid deficiency can cause anaemia, slowed growth, digestive disorders, memory loss and premature grey hair.

Where can I find it? - Dark green vegetables are a rich source, so are legumes, mushrooms and whole-wheat foods.

Minerals are just as important to our diet than vitamins. They perform a variety of jobs in our body. Here are some of the most important minerals needed in our diet:

Calcium - The most important mineral is calcium. This is vital for the development of strong bones and teeth, so teenagers need more than adults do. It's also essential for muscle contraction, blood clotting and conducting impulses along nerves.
Calcium deficiency can lead to osteoporosis in later life - brittle bones and slumped posture. It can also cause heart palpitations, muscle cramps and sleeplessness.

Calcium has a soothing effect, which is why milk-based bedtime drinks are popular.

Where do you get calcium? - Well, it's most readily available in dairy products such as milk and milk shakes, cheese, yoghurt and ice cream. But it also comes in leafy green vegetables, pulses, water and dried fruits.

Iron - Iron is also vital, as it's used to produce haemoglobin, the part of your red blood cells that carries oxygen all around your body. Iron is also involved in some enzyme activities, i.e. biochemical processes.
If you don't get enough iron you're at risk of anaemia - low red blood cell count - which leaves you tired, pale, short of breath and vulnerable to infection. Iron deficiency is common among teenage girls because they lose iron during menstruation.

Where do you get iron? - The richest sources are red meat and liver, but iron is also found in leafy green vegetables, molasses, lentils, pulses and dried fruit, as well as wholemeal bread.

Fluoride - You need fluoride to grow strong bones and teeth, and a lack of it can lead to tooth decay.

Where do you get fluoride? - You find fluoride in seafood and soybeans. It's also in tea and coffee - but go easy on these, as too much caffeine isn't good for you. Anyway, sodium fluoride is often added to the water supply to fight tooth decay.

Zinc - Zinc is another important mineral for growth, healthy skin, wound healing, energy production and development of the reproductive organs.
Zinc deficiency can affect all these areas and cause susceptibility to infection.

Where do you get zinc? - Plenty of zinc is found in shellfish, yeast, whole-grain cereals and legumes.

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