Fit and healthy

1. Fit and healthy

2. Nutrients There are 7 different types of nutrients which are: carbohydrate, protein, fat, minerals, vitamins, fiber, and water. some nutrients are particularly rich in certain food for example, carbohydrate is used for energy and is meanly rich in: cereal, bread, pasta, rice and potatoes. Protein which is used for growth and repair is rich in: fish, meat, eggs, beans, pulses, and dairy products. Fat which is used for energy and storing in energy in the body to insulate it against the cold is rich in butter and oil . Minerals which are used in small amounts to maintain health is rich in: salt, milk, and liver. Vitamins which are also used for health is rich in: dari food, fruit and vegetables. Fiber which is good for keeping food going down the guts and is rich in fruit and vegetables. Water is used for the cells and body fluids and is rich in water.

3. Effects of poor diet It is important that you get the right amount of nutrient in your diet, if you have too little of a particular food its said you have a deficiency in that nutrient. For example if you have deficiency in fiber you could get constipation. If you have deficiency in iron you could have few red blood cells. People with iodine deficiency may get a swelling in their neck called a goiter. Although we need small amounts of different vitamins, we become ill if we don't get enough of each vitamin. For example deficiency in vitamin A can cause blindness, deficiency in vitamin C could cause scurvy which makes gums bleed, and less vitamin D could cause rickets which makes the legs bow outwards in growing children.

4. Too tin, too fat Food is a store of chemical energy. If you look on the side of food packets you will see the food's energy content. This is usually measured in kilojoules, kJ. If we eat too little food, we will use up our store of fat and become too thin. If we eat too much food, especially foods rich in sugar and fat, we will increase our store of fat and become too fat. It is important to balance the amount of food we eat with who we are and what we do. The amount of energy we need from our food depends on our age, our height and how much exercise we get. For example, a one-year old baby needs 3850 kJ each day to continue to grow, whereas an adult Olympic swimmer in training needs 15,600 kJ each day. Someone who sits at a desk all day will need less food than their twin who climbs ladders all day to wash windows.

5. Digestive system The food we eat has to be broken down into other substance that our bodies can use. This is called digestion, without digestion we could not absorb food into our bodies to use it. Digestion happens in the digestion system, which begins in the mouth and ends in the anus. After we swallow, our food passes through these organs in turn:esophagus or gullet, stomach, small intestine and the large intestine. Stages of digestion - food is digested in the mouth, stomach, and small intestines. Then digested food is absorbs into the blood stream in the small intestine. After that excess water is absorbed back into the body in the large intestine. undigested food passes out of the anus as faeces (pronounced "fee-seez") when we go to the toilet. The liver and the pancreas play important part in digestion. The liver produces bile, which helps the digestion of fat. The pancreas produces chemicals called digestive enzymes.

6. Digestion and enzymes The digestive system starts in the mouth with our teeth breaking the food into small pieces, however these pieces are still to large to be absorbed by the body. Food has to be broken down chemically into really small particles before it can be absorbed. Enzymes are needed so that this break-down happens quickly enough to be useful. Different types of enzymes are used to break down different types of nutrieents. For example Carbohydrates are digested in the mouth, stomach and small intestine. Carbohydrase enzymes break down starch into sugars. Proteins are digested in the stomach abd small intestine Protease enzymes break down proteins into amino acids. Digestion of proteins in the stomach is helped by stomach acid, which is strong hydrochloric acid. This also kills harmful micro-organisms that may be in the food. Lipase enzymes break down fat into fatty acids and glycerol. Digestion of fat in the small intestine is helped by bile, made in the liver. Bile breaks the fat into small droplets that are easier for the lipase enzymes to work on. Minerals, vitamins and water are already small enough to be absorbed by the body without being broken down, so they are not digested.Digestive enzymes cannot break down fibre, which is why it cannot be absorbed by the body.

7. Abroption and egestion The process of digestive system is: ingestion (eating) → digestion (breaking down) → absorption → egestion Abroption - digested molecules are absorbed in the small intestins and then enter our blood stream. After that they are carried around the body, where ever needed, br the blood stream. The inside wall of the small intestine needs to be thin, with a really big surface area. This allows absorption to happen quickly and efficiently. If the small intestine had a thick wall and a small surface area, a lot of digested food might pass out of the body before it had a chance to be absorbed. To get a big surface area, the inside wall of the small intestine is lined with tiny villi (one of them is called a villus). These stick out and give a big surface area. They also contain blood capillaries to carry away the absorbed food molecules. Egestion - Excess water is absorbed back into the body in the large intestine. What is left then is undigested food. This is stored in the rectum, the lower part of the large intestine, until we are ready to go to the toilet. It then comes out of the rectum through the anus as faeces. This process is called egestion.

8. Smoking and health Smoking is very harmful to health. It causes around 80 per cent of deaths from lung cancer, bronchitis and emphysema in the UK, and almost a fifth of UK deaths from heart disease. Tobacco smoke contains many harmful substances. These include: tar nicotine carbon monoxide Tar causes cancer of mouth, lungs and throat. It coats the surface of the breathing tubes and the alveoli. This causes coughing and damages the alveoli, making it more difficult for gas exchange to happen. Smoke Cells in the lining of the breathing tubes produce sticky mucus to trap dirt and microbes. Cells with tiny hair-like parts, called cilia, normally move the mucus out of the lungs. Hot smoke and tar from smoking damages the cilia. So smokers cough to move the mucus and are more likely to get bronchitis. Nicotine Nicotine is addictive - it causes a smoker to want more cigarettes. Nicotine also increases the heart rate and blood pressure, and makes blood vessels narrower than normal. This can lead to heart disease. Carbon monoxide Carbon monoxide is a gas that takes the place of oxygen in red blood cells. This reduces the amount of oxygen that the blood can carry. This means that the circulatory system has to work harder, causing heart disease.

9. Drugs and health Drugs are substances that have effects on the body. Medicines are drugs that help people suffering from pain or disease. Recreational drugs are taken for pleasure. Some recreational drugs are legal, such as tobacco, alcohol and caffeine. Most other recreational drugs are illegal, such as cannabis, ecstasy and heroin. Problems with drug use Recreational drugs can be classified as depressants or stimulants. Most recreational drugs can be addictive. All drugs can damage the liver, because it is the liver that breaks drugs down in the body. Any drug that is misused can cause damage to the body, as well as personal and social problems. Injecting any drug with a needle and syringe that someone else has used may lead to a number of diseases from infected blood, including HIV and hepatitis. Depressants slow down messages in the brain and along the nerves. Alcohol is a depressant. It is found in beer, wines and spirits such as vodka. Other depressants include cannabis, heroin and solvents (eg glue and aerosols). Here are some of the typical effects depressants have on the body: feelings of well-being, slowed thinking, slowed muscular activity, a distorted view of the world,or hallucinations Some of the long-term effects of depressants on the body include damage to the liver, brain and heart. They can also have the following effects: alcohol can cause weight gain solvent abuse causes a rash around the nose and mouth cannabis causes loss of memory and concentration, as well as an increased risk of mental illness.

10. Stimulants Stimulants speed up messages in the brain and along the nerves. This makes you feel more alert. Caffeine is a stimulant and is found in cola drinks, coffee and tea. It makes you feel more energetic and alert, but it can also cause insomnia (difficulty in sleeping), headaches and nervousness. Cocaine, ecstasy and amphetamines are all illegal stimulants. They make you feel more energetic and confident, but they can damage the liver and heart. They can also cause loss of memory and concentration, and bring an increased risk of mental illness.