Human growth

For healthy growth and development humans require a balanced diet.

The major food groups that make up a balanced diet are carbohydrates, fats and proteins.

Food groupSourcesFunction
CarbohydratesFruit, vegetables, bread, pasta, riceProvide energy for cell activities
FatsButter, cream, cheese, meatEnergy storage and insulation
ProteinsBeans, eggs, meat, milkProvide building materials for growth and repair
Bread, grain, pasta, potatoes and rice.
Butter, cream, cheese, ice cream and pork pies.
Lamb chops, beef steaks, eggs and salmon.

A healthy diet also includes vitamins and minerals. The lack of a certain vitamin or mineral in the diet can result in a deficiency disease.

VitaminSourcesFunctionDeficiency disease
ADairy products and oily fishHealthy skin, good vision in low light and strong immune systemNight blindness: difficult seeing in low light conditions
CWide variety of fruit and vegetables, especially citrus fruits like orangesHelps maintain cells that give support and structure to the body and helps injuries to healScurvy: tiredness, joint pain, bleeding and swollen gums
DOily fish and eggsHelps body to absorb calciumRickets (in children): weakening of the bones
MineralSourcesFunctionDeficiency disease
CalciumDairy products, green leafy vegetables like spinach, and nutsNeeded for formation of strong bones and teeth, blood clotting and control of muscle contractionsRickets (in children): softening and weakening of the bones
IodineSea fish, cows’ milk and cerealsNeeded by thyroid gland to make hormones that regulate energy release and growth in cellsGoitre: swelling of thyroid gland to create a lump in the throat
IronMeat, dried fruit and nuts, dark-green leafy vegetablesNeeded to make a protein that allows red blood cells to transport oxygenAnaemia: a decrease in the number of red blood cells means that body cells receive less oxygen and are less able to release energy from food. This results in tiredness and pale skin.

Water is also vital for healthy growth and development. All cell reactions happen in solution, and water is used to transport dissolved nutrients and waste products around the body in the blood.