Elements required by the body

Carbon

Hydrogen

Oxygen

Nitrogen

Sulphur

Phosphorus

Iron

Calcium

Magnesium

Potassium

Sodium Chlorine Iodine (traces) Fluorine (traces) Silicon (traces)

Foodstuffs furnishing these elements

Proteins - furnish carbon, hydrogen, oxygen, nitrogen, sulphur, and sometimes phosphorus and iron Fats - furnish carbon, hydrogen, and oxygen Carbohydrates - furnish carbon, hydrogen, and oxygen Mineral matter - furnishes phosphorus, iron, calcium, magnesium, sodium, potassium, chlorine, iodine, fluorine Water - furnishes hydrogen and oxygen

General functions of these foodstuffs

To supply energy

To supply building material

To regulate body processes

Special functions of each foodstuff

Proteins - supply energy ; also nitrogen, sulphur, and sometimes phosphorus for body building Fats - supply energy in the most concentrated form Carbohydrates - supply energy in the most economical form Mineral matter - supplies building material and helps to regulate body processes Water - supplies necessary material (about 60 per cent of body being water) and helps to regulate body processes

Examples of food materials rich in each of the foodstuffs

Proteins Eggs Milk Cheese Lean meats Fish

Mineral matter Milk

Green vegetables Fruits Whole wheat and other whole cereal products Egg yolk

Fats Cream Butter Meat fats Vegetable oils Nuts Yolk of egg

Water Fresh fruits Fresh vegetables Milk

Beverages, including water as such

Carbohydrates

Cereals and cereal products Potatoes and other starchy vegetables Chestnuts Sweet fruits Sugar

Digestion of the foodstuffs

Having seen what each of the foodstuffs does in nourishing the body, we may now see how they are prepared for the use of the body in the digestive tract.