B1.1.1 Diet and Exercise

B1.1.1 Diet and Exercise


A combination of a balanced diet and regular exercise is needed to help keep the body healthy.

Healthy Diet

  • A healthy diet contains the right balance of the different foods you need and the right amount of energy.
  • These foods should provide the following nutrient groups:
    • Carbohydrates for energy and to make cell structures
    • Fat for energy and insulation and cell structures
    • Protein to control cell reactions (as enzymes) and to build cell structures
    • Vitamins and minerals to help our bodies function well.



  • A person is malnourished if their diet is not balanced.
  • This may lead to a person being overweight or underweight.
  • An unbalanced diet may also lead to diseases.
  • Lack of essential nutrients in the diet can lead to deficiency diseases.
  • Excess intake of high energy foods can lead to type 2 diabetes.
    • This is a disease where the person is unable to control the levels of sugar in their blood.
    • This is very dangerous, and the person must carefully control their diet and monitor their blood sugar levels regularly.


Slimming programmes

  • A person gains mass when the energy content of the food taken in is more than the amount of energy expended by the body.
  • A person loses mass when the energy content of the food taken in is less than the amount of energy expended by the body.
  • An effective slimming programme advises people to reduce the energy content of their food, and to increase the amount they exercise.
  • Some slimming programmes encourage people to consume a low proportion of one of the nutrient groups in their diet. This may enable them to lose weight, but it will not necessarily be a sensible, healthy diet.



  • Exercise increases the amount of energy expended by the body.
  • People who exercise regularly are usually healthier than people who take little exercise.
  • They expend more energy and their circulatory system becomes more efficient.
  • They are likely to have lower blood pressure, and less likely to be overweight.


Metabolic rate

  • This is the rate at which all the chemical reactions in the cells of the body are carried out.
  • One major set of metabolic reactions is respiration.
  • The rate of these reactions vary with the amount of activity you do.
  • The more activity, the more energy is required by the body.
  • Metabolic rate also varies with respect to the proportion of muscle to fat in your body.
  • The higher the proportion of muscle to fat, the higher the metabolic rate.
  • Exercise increases the proportion of muscle to fat.



  • Inherited factors can influence our health.
  • We can inherit genes from our parents which can influence our metabolic rate.
  • We can also inherit genes which influence our cholesterol level.
  • Cholesterol is a substance that our body creates from fat that we consume in our diet.
  • Cholesterol is needed to make cell membranes.
  • However, too much cholesterol can increase the chance of cardio-vascular diseases, such as strokes, heart attacks and thrombosis.