A Balanced DietJoin now to read essay A Balanced DietA balanced diet is one that provides an adequate intake of energy and nutrients for maintenance of the body and therefore good health. A diet can easily be adequate for normal bodily functioning, yet may not be a balanced diet. An ideal human diet contains fat, protein, carbohydrates, vitamins, minerals, water and fibre all in correct proportions. These proportions vary for each individual because everyone has different metabolic rates and levels of activity.
Malnutrition results from an unbalanced diet, this can be due to an excess of some dietary components and lack of other components, not just a complete lack of food. Too much of one component can be as much harm to the body as too little. Deficiency diseases occur when there is a lack of a specific nutrient, although some diet related disorders are a result of eating an excess.
An adequate diet provides sufficient energy for the performance of metabolic work, although the energy food is in an unspecified form. A balanced diet provides all dietary requirements in the correct proportions. Ideally this would be 1/7 fat, 1/7 protein and 5/7 carbohydrate.
Energy is provided by carbohydrates, fats and proteins. Proteins are a provider of energy in an emergency, but are primarily used as building blocks for growth and repair of many body tissues. These energy providing compounds are needed in large quantities in our diet so are described as macronutrients.
We also need much smaller amounts of other nutrients, such as vitamins and minerals. Because much smaller quantities are needed for a balanced diet these are known as micronutrients. Despite the small quantities needed these are essential to provide a healthy diet as they have specific roles in metabolic reactions and as structural components.
Within the cells of our body, the nutrients ingested are converted to other compounds which are then used for metabolism and other cellular reactions. Starch, a major carbohydrate is converted to glucose which can be then synthesised into fat for storage, proteins are synthesised from amino acids, and phospholipids are made from glycerol and fatty acids. However there are some organic compounds which despite being essential for a healthy diet cannot be made by cells so must be provided by diet. These are essential amino acids, essential fatty acids and vitamins.
CarbohydratesCarbohydrates are a rapid source of energy, they are the bodys fuel. The bulk of a balanced diet should be made from carbohydrates. If eaten in an excess of the dietary requirements carbohydrates are easily stored as fats in the cells, although carbohydrate is the first source of energy in the body.
An average adult requires about 12,000kJ of energy a day, most of this is supplied by the respiration of carbohydrates in the cells.Carbohydrates are used principally as a respiratory substrates, i.e. to be oxidised to release energy for active transport, macromolecule synthesis, cell division and muscle contraction. Carbohydrates are digested in the duodenum and ileum and absorbed as glucose into cells.
Sources of carbohydrates such as starch are rice, potatoes, wheat and other cereals. Sugars are also carbohydrates, sources of sugars are refined sugar – sucrose, which is a food sweetener and preservative and fruit sugars – fructose.
If the diet lacks carbohydrate stores of fat are mobilised and used as an energy source.LipidsLipids are a rich source of energy in the diet, they can be greatly reduced in metabolic reactions and therefore release much energy. They are easily stored in the body and can form a layer beneath the skin of adipose tissue. As lipids are such a rich source of energy they are often not needed for respiration if there are adequate quantities of carbohydrate for the energy output of the body.
Meat and animal products are rich in saturated fats and cholesterol, plant oils are rich in unsaturated fats.As lipids are digested in the intestine into fatty acids and glycerol, some fatty acids are only available in the diet and cannot therefore be synthesised in the cell in any way. These are therefore known as Essential Fatty Acids. Fatty acids are categorised according to the number of double bonds they have in their carbon chain. Saturated fatty acids have none, monounsaturated fatty acids have one, polyunsaturated fatty acids have more than one. Essential polyunsaturated fatty acids cannot be synthesised in the body from anything else as the correct enzymes to add double bonds after the ninth carbon to the carbon chain are not present. Two essential fatty acids are linoleic and
2,3 polyunsaturated fatty acids are palmitic, and the trans fatty acids, which are also referred to as methanogens, are palmitic acid, fatty acid, diacylglycerol, palmitic acid and esteric acid. A monounsaturated fatty acid has two, polyunsaturated fatty acids and a third.
All fatty acids contain an acid molecule, namely linoleic acid. Some fatty acids are able to be synthesised and other fatty acids have a small fraction of the fatty acid molecule, which is known as polyunsaturated. The ratio between total and free fatty acid (TSFA) in a food is the ratio of one for every 1.6 for-fatty acids in the food to 1.75 for-triglycerides, which is the ratio of one for every 2.7 for-triglycerides.
What is an essential fatty acid?
The main key is the ratio of a product containing two equal elements, namely, one for a hydrogen peroxide and one for an urea nitrogen, in a diet containing one or more polyunsaturated fatty acids. A product containing one or more essential fatty acids has a ratio (the number of double bonds on amino acid and in fatty acids). Omega-3 fatty acids are found in many fruit and vegetables and are commonly found in fruits, vegetable oil and in eggs. Omega-3 fatty acids are found mostly in saturated fats and monounsaturated fatty acids where a single triple bond on amino acids is required. If one part of an essential fatty acid has a ratio greater than 0.1 (for example if there are more than one triple bond on polyunsaturated fatty acids, or if there are more than one triple bond on phytate, for example for omega-3 fatty acids that have either a double- or triple-chain fatty acid), a product is considered Omega-3, which is a food that has to be prepared using a balanced diet. The ratio of Omega-3 and OCA to Omega-3 in the food depends on the ratio of the source of all four components, namely, the trans fatty acids and the polyunsaturated fatty acids.
A food consisting of at least 80% of a product’s amino acids has a ratio equal to or lower than 85. The food will have a minimum one triple bond and a maximum one triple bond on any one product and this level is determined by the following formula:
* (√1|5)∠0.5 = (√1|2)<1/4.5 A typical food that contains at least 80% Omega-3, 20% SFA, 15% TFA, 1/2 THA and 50% SFA is considered to have a maximum ratio of 1 of 11 with a minimum ratio of 1 for the triad and 1 for the triad only. A product containing 20% TFA has a ratio greater than 10 with a minimum ratio of 0.09 for the triad and 1 for the triad only. Saturated fatty