Eating well is one of the best investments you can make for your health, so it's worth paying it some serious attention.

Aims of good nutrition

By eating a healthy diet and being physically active, we can maintain a healthy body weight and reduce our risk of developing diet-related illnesses, such as heart disease and cancer. However, although healthy eating is pretty straight forward, there's much confusion among the general public about what constitutes a healthy diet, as well as a belief by many that they are already consuming a healthy diet. For example:

• 69.3 per cent of people think that their diets are already healthy (Cotugna et al, 1992), and
  
• 71 per cent of people agree with the statement 'I do not need to make changes to the food I eat, it is already healthy enough.' (Kearney et al, 1997).

In order to become and remain healthy, our bodies need good food, and the time and energy to process it and use it, to help us feel well. Healthy eating provides all the necessary nutrients to create and repair tissues, to sustain a healthy immune system and to enable the body to execute daily tasks with ease.

Links between diet and disease are better understood than ever before, and there's a large body of evidence showing that what you eat has an enormous impact on health. Our lifestyles and eating habits have changed drastically over the past couple of decades. We now rely more on convenience food and nutritional supplements than on fresh food. Much media attention has focused on what foods you shouldn't eat, rather on what foods you can and should eat.

Remember, there's no such thing as a bad or good food - moderation and balance is the key. Food should be enjoyed - it is possible to eat delicious, tasty food that's healthy too.

The aim of a healthy diet and lifestyle in adulthood is to ensure you're fit, healthy and full of vitality in the short term, with healthy teeth, immune system, skin and hair, abundant energy and an ideal body weight. In the long term, the aim is to minimise the risk of chronic diseases such as coronary heart disease, stroke, diabetes, cancer and osteoporosis.

Nutritional considerations
Providing the essentials
Energy: like all machines, the human body needs a constant supply of energy (or calories). Without it, essential body functions would be impossible. Energy is derived from the energy-bearing nutrients in food: complex carbohydrate, fat, protein and simple sugar.

Protein: as well as providing energy, protein is vital for growth and repair.

Vitamins and minerals: although only required in minute amounts, these are the cornerstones of good health and are essential for many body functions. Without them, key processes at cellular level are unable to operate.

Fibre: this is a blanket term for all unabsorbed food that goes through the digestive tract. It is vital to help stimulate the bowels to excrete waste products on a regular basis, ensuring absorption of nutrients from food occurs in a controlled and gradual fashion.

Water: this isn't a nutrient as such, but is still an essential part of any diet. Without fluid the body can only survive for a couple of days. Water is needed to flush waste products from the body, to keep the skin, hair and body organs healthy, to produce digestive enzymes, and to enable the body to glean all the beneficial nutrients from the foods and drinks we consume. Many people don't drink enough water - we need on average at least eight glasses of fluid every day.