Dietary requirements and the Process of Digestion
This report will start by identifying and evaluating information on the variations of dietary requirement, taking into consideration age, sex and activity. It will then explore the way diet might contribute towards disease and illness. The report will further describe the physical processes involved in digestion and explain their importance in the body. (1.1) Dietary Requirements and Variations (According to Age, Sex & Physical Activity)
A balanced diet is one that contains the right quantity of nutrition that an individual needs, for energy, to support growth and maintain a healthy body. It comprises of macronutrients which are proteins, fats and carbohydrates, these provide energy and are needed daily in large quantities. Micronutrients which are vitamins and minerals needed to release the energy but only needed in small amounts. Water although not a nutrient is essential and required daily in considerable amounts. (McGuiness 2010) * Protein – this is made up of oxygen, hydrogen, carbon, nitrogen, sulphur and iron. Proteins have two important functions, growth and tissue repair, It is estimated that the human body contains over 50,000 types of protein.
(Le Quesne 2003) Proteins that are used in the diet are made of long chains of amino acids and fit mostly into two categories, non-essential and essential amino acids. Over half of amino acids are non- essential meaning that the body produces them for itself. Essential amino acids are provided in the diet as the body is not capable of creating them. There are 9 essential amino acids required in childhood and 8 in adulthood these are needed on a daily basis. Sources of protein are fish, eggs, milk, meat, beans and peas. If too much protein is consumed the amino acids are broken down in the liver to form urea and passed out in the urine. (Barasi 1997) * Fats – these are composed of oxygen, hydrogen and carbon and supply a strong reserve of energy which can be stored. They help to insulate the body and its organs, assist in repair of cell tissues and are classed as saturated and unsaturated. Saturated fats are solid at room temperature and are the cause of many health problems as they clog up arteries in the body. Sources of these are margarine, lard and butter but can be found in cakes and biscuits to name a few. (SNDRi 2010) Unsaturated fats of which there are two, monounsaturated, can be found in olive oil and polyunsaturated which contains omega 3 and 6 fatty acids, essential in the brain and nervous system, sources are oily fish and flax oil. Unsaturated fat is usually liquid at room temperature. (Bearsden 2006) * Carbohydrates – made up of oxygen, hydrogen and carbon, they supply most of the energy for all the body’s functions. Carbohydrates are made up of single sugar units or as chains known as monosachaccarides , dysaccharides and polysaccharides. Monosaccharides are simple carbohydrates such as those found in fruit and honey, they are easily absorbed into the body and digested as are dysaccharides. Polysaccharides are referred to as complex carbohydrates and are found in potatoes, beans etc. They have to be digested in the small intestine and supply more energy for longer, maintaining blood glucose levels in the body. Glucose is an important monosaccharide that provides all the body’s cells with energy, and is the only supply used by the brain. The glycaemic index is a guide that measures the effect that carbohydrates have on blood sugar levels. The higher the GI the quicker the carbohydrates are absorbed.(SNDRi 2010) * Fibre – this is categorised as soluble or insoluble and is found in starchy foods. Soluble fibre is found in fruit and vegetables, beans and oats, it helps lower cholesterol which is harmful to the body. Insoluble fibre is found in wheatbran, broccoli etc. which adds bulk to the waste in the body preventing constipation.(Beardsen 2006) *