Energy

• Energy supports activities of the human body.

• Energy is measured either in calories or joules.

• Energy in our diet mainly comes from carbohydrate, protein and mainly fat.

• The amount of energy needed for healthy individuals takes account of various factors such as age, gender, body weight and activity level.

Food Pyramid

Carbohydrate• Carbohydrate is the major source of energy in

our diet and is also the preferred fuel in our body.

• 1 gram of carbohydrate provides 4 kcal.

• Exapmles of carbohydrate are sugars (including monosaccharides, disaccharides) and polysaccharides eg: starch, glycogen

• Sugar, syrup and honey are rich in monosaccharides or disaccharides;

• Cereals and root vegetables (eg potatoes) are rich in starch.

Protein

• Protein is essential for growth and cell repair.

• Protein also provides energy; 1 gram of protein provides 4 kcal.

• Meat, fish, milk, eggs and legumes are rich in protein.

• Lack of proteins causes Kwashiorkor

Do not learn any of these diagrams but look at pictures to understand what you are talking about

Two amino acids join together to form a dipeptide. There is a peptide bond between them.

Many amino acids join together to form a polypeptide. A large polypeptide is called a protein.

When you cook things with proteins the heat causes the protein to lose

its shape (denaturation) but the goodness is still in it.

Fats/ Lipids• Fats provides the most energy: 9 kcal

per gram.

• It can mainly be divided into saturated fat, unsaturated fat and polyunsaturated fat. Saturated Fats comes from eggs, milk, cream and butter. Unsaturated Fats come from plant and fish sources such as peas, beans nuts, cooking oil, and oily fish.

• Excessive fat intake, especially saturated fat, leads to health problems, such as heart diseases, obesity and certain types of cancers.

• Cutting out fat and carbohydrates from your diet can also lead to diseases.

• Fats are made from glycerol and 3 fatty acids.

• Glycerol and fatty acids contain the elements carbon, hydrogen, and oxygen. Fats contain a lot of carbon. This is why they give us so much energy.

• Fat does not as much hydrogen as cabohydrates.

• Fats provide energy, form part of cell membranes and are stored under the skin in adipose tissue for insulation.

Fibre /Roughage

• Dietary fibres are important for proper bowel function (no constipation) and may provide other health benefits such as a healthy colon, prevents colon cancer and helps in weight management.

• Whole grain cereals and whole grain cereal products, dried fruits, nuts, fruits and vegetables are rich in dietary fibres.

Vitamins

• Vitamins are organic (carbon containing) molecules. There are 2 types:

• Fat soluble: A, D, E, K• Water soluble: B, C (Therefore removed with urine).

Both can be stored in Liver

• Essential Vitamins: need to be supplied daily in your diet as your body cannot produce them (Vitamins B, C).

• Non-essential vitamins are those that can be produced by body (Vitamins A, D, E K).

Vitamin B• Vitamin B are a group of 8 vitamins.

Can also be known by other names eg: folic acid, thymine…

• Sources of food that contain vitamin B are rice, oranges, legumes and leafy green vegetables.

• Vitamin B is needed for normal functioning of the nervous and circulatory systems.

• Vitamin B prevents Beriberi, a deficiency disease were inflammation or breakdown of the nerves, digestive system and heart occurs.

Vitamin C• The major roles of vitamin C

are to prevent Scurvy and promote wound healing.

• It is also an important antioxidant, which may help reduce the risk for cancers and certain chronic diseases.

• Citrus fruit such as grapefruits, oranges, lemons as well as kiwi and strawberries are rich in vitamin C.

Diagram showing Scurvy

Vitamin K• Vitamin K is needed for the

proteins that build and maintain bone and it is also involved in blood clotting.

• Vitamin K is produced by the bacteria naturally living in the human intestines.

• Sources of vitamin K include certain dark green leafy vegetables( such as spinach, turnip greens and brussel sprouts) and certain vegetable oils (soybean and olive)

Bacteria that produce Vit K

•Vitamin A is required for good night vision as it forms an important part of the retina and growth.

•Liver, egg yolks, milk, cheese, spinach, pumpkin and papaya are rich in vitamin A.

•One of the first detectable signs of vitamin A deficiency is Night-blindness.

Vitamin A

Retina of eye

•Vitamin D is needed for bones and healthy teeth.

•Lack of Vitamin D will give rise to Rickets.

Rickets

Minerals

• Nutrients found in food as a compound rather than as a free element. Minerals are important in regulating many body functions.

• Mineral deficiency occurs when there is an inability to use one or more of the mineral elements needed for human nutrition.

• All mineral deficiencies are treated by adding the specific element to the diet, either as a pill or in the right foods.

Calcium

• Calcium is important for promoting bone and teeth health.

• Milk, cheese, yoghurt, dark green vegetables and dried legumes are rich in calcium.

• Inadequate calcium intake may lead to low bone density and even Osteoporosis.

Phosphorus

•More than 85% of the phosphorus in the adult body is found in the bones. Phosphorus is a major component of most cells in the body.

•Food sources of phosphorus occur both naturally and as food additives (phosphate salts). Foods high in phosphorus include milk, milk products, eggs, grains and legumes

Sodium

• The major dietary intake of sodium is from salt.

• Sodium plays an essential role in the regulation of body fluids and its acid-base balance.

• Sodium should be consumed in moderation as it may increase the risk of high blood pressure

Iron

• One major function of iron is the formation of haemoglobin. Therefore it is important for formation of blood.

• Lean meat, eggs, legumes, whole grains and dark green vegetables are rich in iron.

• Inadequate intake of iron may cause Anaemia.

Lack of Red Blood Cells

Iodine•Iodine is vital for good thyroid function, which in turn is essential for health.

•Iodine deficiency during pregnancy can give severe motor impairments and irreversible mental retardation and. In adults low/ very high iodine intake can cause the Goiter (an enlarged thyroid gland).

•Iodine is found in shellfish, seaweed and some types of fish.

Floride

•Floride is important as it helps strengthen the outer layer of the teeth – the enamel. It prevents Tooth decay.

•Floride is found in toothpastes as sodium floride.

•Do not ingest any fluoride. Fluoride is a violent poison.

Water• Water makes up the last class

of nutrients. It has many necessary functions in the human body.

• Some of its actions include its use as a solvent;

• as a lubricant;• as a conduction system for

transportation of nutrients and unnecessary waste;

• it helps in temperature regulation;

• it forms part of cytoplasm of all cells and of vacuoles in plants.

• There are many available sources of water other than tap water and bottled water. Some foods have a high water content, including many fruits and vegetables.

• It is recommended that people drink eight cups (or nearly 2 liters) of water a day to maintain an adequate supply.