The healthiest way to lose weight is neither crash diets nor bursts of exercise. The body likes slow changes in terms of food and exercise.

For example, someone who has not exercised for years should not rush into running miles a day or pounding the treadmill. Not only will the struggle to do so leave you feeling disheartened and demotivated, you're also far more likely to injure yourself and set your fitness levels back further.

The same goes for people who suddenly start starving themselves. Diets that severely restrict calories or the types of food 'allowed' can lead you to be deficient in the nutrients and vitamins that your body needs.

So if you need to lose weight, what should you do?

Energy needs and weight loss

Your body uses food for energy. It stores any excess energy as fat. This means if you eat more food than your body needs for daily activities and cell maintenance, you will gain weight.

To lose weight, you need to get your body to use up these stores of fat. The most effective way to do this is to:

• reduce the amount of calories you eat
  
  
• increase your levels of activity.
  
  

This is why experts talk about weight loss in terms of diet and exercise.