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 hasn't exercised for years shouldn't 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...