Human Biology Topic 3 Nutrition PDF

Human Biology and Health Studies Topic 3 Nutrition  Nutrition Nutrition is the study of how the body uses the nutrients from the food we eat to provide energy needed for growth, repair and reproduction. We get these nutrients from carbohyd...

Human Biology and Health Studies Topic 3 Nutrition  Nutrition Nutrition is the study of how the body uses the nutrients from the food we eat to provide energy needed for growth, repair and reproduction. We get these nutrients from carbohydrates, proteins, fat, vitamins and minerals as well as water and fibre. To stay healthy we need to eat a good balance of the different kinds of nutrients. What is the difference between a balanced diet and a healthy diet? ACTIVITY Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Common foods that contain proteins: Gelatin is a mixture of peptides and proteins produced by partial hydrolysis of collagen extracted from the skin, boiled crushed horn, hoof and bones, connective tissues, organs and some intestines of animals such as domesticated cattle, chicken, horses, and pigs. Eggs are a great source of protein. One egg has anywhere from 6 to 6.5 grams of protein in it depending on the size. The yolks have about 3 grams of protein and the whites have about 3.5g. Boiled eggs or raw eggs? You don't burn up macronutrients in the cooking process. If that was true, then the fats of the egg would also "burn up" because that is a macronutrient as well. This does not render the protein completely useless. Tonkotsu "pork bone" ramen usually has a cloudy white colored broth. It is similar to the Chinese baitang and has a thick broth made from boiling pork bones, fat, and collagen over high heat for many hours.  Protein Protein is present in meat, dairy products(such as milk), eggs, legumes (peas, beans and pulses) and nuts. We need proteins for: Building and repairing body tissues, particularly muscle tissue. Making enzymes that are needed for metabolism. Building antibodies which protect us against disease. Children who lack proteins will suffer from kwashiorkor and marasmus.  Carbohydrates Carbohydrates is present in sugars, starch and cellulose. Cellulose is the material which forms plant cell walls which is difficult to digest, so most of our carbohydrates come from food containing sugar and starch. Are mainly found in plants such as ground provisions (yams, cassava, potatoes, etc.), fruits, vegetables, peas and beans. Also in some animal products such as milk, yoghurt and cheese. It also provide us with energy. A deficiency in carbohydrates result in lack of energy.  fats and oils (lipids) Fats are found in foods that come from animals, such as cheese, butter, margarine, cream, lard, milk and red meat. Oils are mostly found in foods from plants, especially the seeds and fruits. Some fish also contain high levels of oil. Fats are important because they: Can be digested to provide energy and water; Contain fat soluble vitamins D and E; Act as insulation to protect internal organs. A diet high in animal fats is often associated with heart and circulatory disease.  Water Water is very important for the survival of living organisms since all chemical reactions in our bodies requires it. We contain 70% water by mass. In humans, water is also required for: Transporting nutrients and waste products. Digestion, absorption, circulatory, and excretory functions; Absorption of water soluble vitamins; Maintaining proper body temperature.  water Water is constantly lost from the body by breathing and sweating so on average we need to drink at least 2 litres of water daily. A total lack of water for five or more days will result in death. People who do not drink sufficient water will suffer from headaches, poor concentration, tiredness, kidney infections and constipation. Drinking too much water is also dangerous as it dilutes the fluids in the body too much causing water intoxication.  fibre Dietary fibre is also called ‘roughage’. We get this mainly from plants such as fruit, vegetables and grains. It is not truly a food since it cannot be digested in the human body however it is important since it allows for the easy elimination of faeces. It retains water, which results in softer and bulkier faeces and prevents constipation. It also reduces the risk of colon cancer since the fibres in the faeces clean the colon as it passes out.  Vitamins and minerals Vitamins and minerals only need to be eaten in small amounts to keep us healthy. However, they contain elements that are essential to many of the functions of our body, so a deficiency in the diet can quickly cause problems. Vitamins are used in many of the reactions in our bodies that convert nutrients into energy and body tissue. We therefore need a balanced diet to stay healthy. QUESTIONS???  BODY MASS INDEX BMI is an inexpensive and easy-to-perform method of screening for weight category, for example underweight, normal or healthy weight, overweight, and obesity. BMI can be used as a screening tool but is not diagnostic of the body fatness or health of an individual. To determine if a high BMI is a health risk, a healthcare provider would need to perform further assessments. In general, a person who has a high BMI is likely to have body fatness and would be considered to be overweight or obese. athletes may have a high BMI because of increased muscularity rather than increased body fatness.  FORMULA BMI is a person's weight in kilograms divided by the square of height in meters. OR a person's weight in pounds divided by the square of height in inches. Example: Weight = 150 lbs, Height = 5'5" (65") Calculation: [150 ÷ (65)2] x 703 = 24.96