Carbohydrates: These are found in breads, pastas, cereals, and usually things that are sweet. They contain elements of oxygen, hydrogen and carbon and are essential as they energise the body. According to http://healthyeating.sfgate.com/steps-digestion-carbohydrates-4053.html “Carbohydrate digestion begins in the mouth. The salivary glands in the mouth secrete saliva, which helps to moisten the food. The food is then chewed while the salivary glands also release the enzyme salivary amylase, which begins the process of breaking down the polysaccharides in the carbohydrate food” - “After the carbohydrate food is chewed into smaller pieces and mixed with salivary amylase and other salivary juices, it is swallowed and passed through the oesophagus. The mixture enters the stomach where it is known as chyme. There is no further digestion of chyme, as the stomach produces acid which destroys bacteria in the food and stops the action of the salivary amylase” (accessed 18/06/13) Once the carbohydrates have gone through this process, they are absorbed in the small intestine and finally it all leaves the body through excretion. Carbohydrates don’t just give us energy to get through the day, they protect our muscles and tissues, when your body needs energy it will pull it from the glucose that the carbohydrates produce, if the body cannot find it, it will take the energy of any fatty tissue in your body. By not giving your body enough carbohydrates, it can result in death, as your body will eat away at muscles and tissue until you eventually run out of all energy and die. Carbohydrates also help your body take in calcium and have been known to lower cholesterol.
Proteins: According to Rasheed and Irvine “Proteins are necessary for the growth and repair of the body and can also be used for energy. Proteins are large molecules made up of smaller units called amino acids. There are 20 amino acids commonly found in plant and animal proteins and there are therefore numerous combinations” (2010:Page272)
Proteins are broken down into amino acids, once protein has been consumed; it is taken into the stomach and broken down during digestion. Protein helps produce energy that aids in the growth and repair of muscles and cells in the body. Proteins also contribute to making tissues in the body which helps to build up your immune system and can also be a source of energy.
Lipids: Lipids are the oils and fats we find in our diet. According to Grosvenor and Smolin “A small amount of lipid digestion occurs in the stomach due to lipases produced in the mouth and stomach” - “The liver produces bile, which is stored in the gallbladder and released into the small intestine to aid in the digestion and absorption of fat” - “The pancreas produces the enzyme pancreatic lipase, which is released into the small intestine to break down triglycerides into fatty acids and glycerol” - “In the large intestine, unabsorbed fat is metabolised by bacteria” (2010:Page128). The fats in our diet are a good source of Vitamin A, D, E and K. Eating these kinds of fats help our body produce hormones which keeps our skin health and prevents loss of body heat.
Vitamins: Vitamins are organic compounds, according to Reavley “Vitamins are substances which, in small amounts, are necessary to sustain life. They must be obtained from food as they are either not made in the body at all, or are no made in sufficient quantities for growth, vitality and wellbeing. Lack of particular vitamin can lead to incomplete metabolism, fatigue and other health problems” (1998:Page3) Vitamins benefit the body by aiding in body and muscle growth and also prevent things such as blindness and help contribute towards muscle functioning. Vitamins are digested by consuming the vitamins through food or tablets, once they have moved down into the stomach they are broken down by the acids in the stomach. Once the broken down food has moved through the stomach and