Describe what the human body requires for a healthy diet

Good health requires a balanced diet that includes all the essential nutrients taken from food. Nutrients that are important: proteins, carbohydrates, fats, vitamins, minerals, and water. The amount of each depends on age, weight, gender and occupation. A well-balanced diet consists of about 60% carbohydrate, 20-30% protein and 10-20% fat. Foods containing these three components will also provide vitamins and 15 essential minerals, such as calcium, magnesium, sodium, iron, and sulfur. We need about 2 liter of water a day. Malnutrition can occur when either too little or too much of these essential components are taken.

Summary: A Healthy Diet should contain

60% Carbohydrate
20-30% Protein
10-20% Fat
Vitamins
14 Essential minerals : calcium, chromium, copper, fluorine, iodine, iron, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, sodium and zinc
Water

Food Groups
milk group-milk, cheese, yoghurt --> supplies calcium, protein, vitamins A&D, fat
meat group-meat, fish, poultry, eggs, legumes, nuts --> iron, vitamin B, energy, fat
vegetable and fruit group --> vitamin A & C
bread and cereal group -->energy, vitamins, minerals, protein
Carbohydrates - source of calories (energy), glucose - important in energy-producing cycles within cells.
Water: necessary for life, biochemical activities within the body

Food pyramid:

external image food-pyramid+portions.jpg

What are Proteins?
Proteins are essential nutrients needed by the body to maintain, build and repair body tissues. Proteins are chains of amino acids linked together by peptide bonds and folded into a specific 3D structure that also have crosslinks, such as disulphide bridges, between specific amino acids to hold it in shape. Refer to C.2 for more specific details on protein structures.
22 amino acids are required for good health, our bodies can only make 14 of these essential amino acids, thus the other 8 can only be obtained from food. These 8 amino acids are commonly called essential amino acids, and are only found in dairy products, meat and fish.

What are Carbohydrates?
Carbohydrates are complex sugar molecules that are made up of long chains of monosaccharide units. Monosaccharides include: glucose, fructose, and galactose. These chains are also known as polysaccharide molecules. Carbohydrates provide the energy required by all cells in the body in the form of glucose, where the cells use glucose in the respiration process to carry out metabolic activities. Refer to C.3 for more specific details on carbohydrate structures.
Wheat, grains, fruits, vegetables and sugary foods such as chocolate and candy, are rich sources of carbohydrates.

What are Fats?
Fats are usually made up of a glycerol molecule with 1, 2 or 3 fatty acids attached to it. The fatty acids form ester bonds with the glycerol and the whole molecule is collectively called a lipid. Fats are needed to provide insulation to the body, a source of energy (however not an instant source like carbohydrates), provide fatty acids (materials) for cell membranes and the myelin sheath of the nerve cells. Refer to C.4 for more specific details on fat structures.
Fat can be found in abundance in oils and butter, and in small amounts in meat, poultry and fishes.

What are Vitamins?
Vitamins are organic components in food that helps with chemical reactions in the body to help maintain a healthy body and also for growth. There are 13 vitamins that are essential to the body, but cannot be produced by the body. Actually ALL vitamins cannot be synthesized in the body. These essential vitamins include: Vitamin A, D, C, K, E.
Refer to C.5 for more information on vitamin structure and specific vitamin functions.
There are 2 groups in which these vitamins are classified under, fat-soluble and water-soluble; Fat-soluble vitamins can be stored in the body, therefore, not a large amount of intakes of these vitamins are needed, or else they will cause poisoning. Water-soluble vitamins cannot be stored in the body, so we need to consume them daily.
Vitamins are found in fruits, vegetables, meat, dairy products, whole grains, and in dietary supplement tablets.

What are Minerals?
Minerals are inorganic compounds that are essential for growth, maintenance of body weight and reproduction. Minerals are found in all foods and in dietary supplements as well.

What is Water?
Water is one of the most important minerals that is required for our body. Although it does not provide energy like all the other nutrients do, water serves as a medium in which these nutrients can be dissolved into and transported around the body and also serves as a medium in which chemical reactions can take place. Water, in the form of sweat, also acts as a cooling agent for our body when our internal body temperatures rises above the optimum 37 degrees Celsius mark; this can occur when we have a fever or when we are exercising.


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