What is an ideal human diet ?
An ideal human diet contains Fats, proteins, carbohydrates, vitamins, minerals, water and fibre in correct proportions.
What are carbohydrates?
They are an energy source. Respiratory substrate oxidised to release energy for active transport, synthesis of macromolecules, cell division and muscle contraction. Digested in mouth and small intestines and is absorbed as glucose.
Common sources for Carboyhydrates?
Rice, potatoes, wheat and other cereal grains.
What are lipids?
They are an energy source, highly reduced and can be oxidised to release energy. Very important in cell membranes and as a componet of steriod hormones which are fat based. Digested in the small intestine and absorbed as fatty acids and glycerol.
What are vitamins?
They have no structure or function, but are essential in small amounts to use other dietary components effiectly. Their absence results in deficiency diseases such as scurvy and rickets.
What is fibre?
Known as roughage it is manily cellulose from plant cell walls. Found in vegetables and cereals. Provides enough energy so that there is no constipation.
What is an adequate diet?
Provides energy for the performance of metabolic work although the energy could be in any form.
What is necessary for a balanced diet?
1/7 fat, 1/7 protein, and 5/7 carbohydrates.
What are proteins?
They are building blocks for growth and repair of body tissue, as enzymes, as transport systems, as hormones and as antibbodies
Common source of proteins?
Meat,fish and eggs.They must contain eight essential amino acids, since humans can not synthesis them. Digested in the stomach and absorbed as amino acids.
What is the deficiency in developing countries cal
Marasmus or Kwashiorkor
What do we need water for?
Every chemical reaction in the body reguires water. A human needs 2-3 dm3 a day.
What do we need minerals for ?
They have a range of specfic roles, and there absence may cause deficiency diseases such as poor growth, teeth and anaemia.
Dangers of malnutration
Diets rich in sugars
Damages tooth enamel and cause tooth decay.
Diets rich in saturated fats and cholesterol
Can cause heart disease. Fatty compouunds block up arteries which supple glucose and oxygen to heart muscle.
Diets in salt
Causes blood pressure to rise.
Diet low in dietary fibre
Causes constipation and cancer of colon.
Diets too high in energy content.
Causes obesity the extra mass and volume causes joint damage, increase of heart disease and circulatory diseases, increase diabetes, infections of the lungs as breathing becomes difficult.