CORE Biology - Diet and Exericise

Regular exercise and a balanced diet are needed to help keep the body healthy.

·         Too little food leads to a person being underweight and prone to certain types of illnesses

·         Too much food leads to a person being overweight and prone to other types of illnesses

A mix of different types of food in the correct amounts is needed to keep the body healthy. The main groups are carbohydrates, fats and proteins.

·         Carbohydrates – found in potatoes, pasta etc. needed for a source of energy for life processes.

·         Fats  - found in cheese, butter etc. needed for source of energy for life processes and make cell membranes and insulate our bodies

·         Proteins – found in meat, fish etc. needed for growth and repair (cells)

·         Mineral ions and vitamins – needed in small amounts for healthy functioning  of the body

An imbalanced diet causes malnourishment e.g.:

·         Little food – underweight

·         Too much food – overweight

A poor diet leads to deficiency diseases e.g.:

·         Little vitamin D – rickets (affects growth of skeleton)

·         Type 2 diabetes – from a poor diet (usually overeating)

If a diet consists of food with a lower energy content than the amount of energy that their body uses then they will lose body mass

The metabolic rate is the speed at which chemical reactions take place. Varies because of:

·         Inherited factors

·         Age

·         Gender

·         Proportion of muscle to fat

·         Amount of exercise

The metabolic rate increases as we exercise and stays high for a while afterwards.

Other factors affect health too, including inherited factors. E.g. cholesterol level in the blood. Cholesterol – made in liver and needed for healthy cell membranes. Too much cholesterol increases risk of heart disease and diseased arteries.