Topic 1: Meaning, Importance and Value of nutrient

Meaning of food

Food is the things that humans and animals eat or drink to nourish the body and make it grow and live. It is also the things that a plant absorbs to feed to each part to grow and live. Our bodies need food which is necessary for our body to still hunger and use the nutrients for good health and brain development.

To nourish the mind, people eat food to fulfill their desire and build their healthy mind. When food is eaten, it becomes profitable to our body, giving it power and warmth, supporting growth, repairing damage and, last not least, causing the organs to work normally.

Nutritional science studies how to provide foods for the healthiest body and considers the value of foods, as well as age and physical condition of consumers.

Advantages and values of foods

Foods are raw materials which the body will be able to transform into energy. The body will use this energy to maintain the chemical processes in each part of the body such as the blood flow, the movement of air in and out of the lungs, body movement, exercise and other activities.

Groups and advantages of nutrients

As nutrition, foods are organized into 6 groups,

1. Carbohydrate - is a nutrient contained in flour and sugar. Most carbohydrates are produced by the

photosynthesis of plants. Carbohydrate is a nutrient that provides the body with energy; one gram of

carbohydrate will produce 4 kilocalories (Kcal) energy.

Advantages of carbohydrate

(1) Give energy and warmth to the body.

(2) Burn fat for the body to use.

(3) Eliminate toxins from the body.

(4) Cause normal excretion.

The amount of carbohydrate a person needs per day is unequal; it depends on body size, age and activity.

2. Protein- is necessary for all living things. It contains important substances such as carbon, hydrogen, oxygen, nitrogen and other substances.

Advantages of protein

(1) Repair the body.

(2) Give energy and warmth to the body. A gram of protein will give 4 kilocalories energy. If a baby receives too little protein, it will impact the brain development and might cause stunting and reduced intelligence.

(3) Causes the body to be strong and not getting exhausted.

(4) Causes an increased immunity.a

(5) It is an important substance in hormone and enzyme production, and an important part of red blood cell.

The lack of protein

(1) May the cause of reduced body size and of easily becoming exhausted.

(2) May inhibit body growth.

(3) May cause weak muscles.

If the body lacks protein, it will cause kwashiorkor with symptoms like swelling of the liver, thinning hair and listlessness. Sources of protein are meat, entrails, egg, milk, and bean. Protein will be digested by enzymes and changed into amino acids.

3. Fatty acid- is a nutrient which contains the key elements of carbon, hydrogen and oxygen. It looks like a carbohydrate but has different proportions. Fatty acids contain amino acids and glycerol.

Fatty acids are grouped into two categories according to their melting point.

Saturated fatty acid has a high melting point and has many carbon and hydrogen atoms in its molecule. There are lauric acid, myristic acid, palmitic acid and stearic acid. Most saturated fatty acids come from animal and coconut fat. Saturated fatty acid increase the cholesterol

level in our blood. It is found mostly in egg yolks and organ meats such as liver, brain and kidney. If a person consumes saturated fatty acid, it may cause obstructions in the blood vessels, vascular coagulation, hypertension etc. To decrease the cholesterol level in the blood, you should consume low fat food and avoid consuming egg yolk and animal meat especially their fatty organs.

Unsaturated fatty acid has a low melting point. The molecules have lower numbers of

carbon and hydrogen atoms. Most unsaturated fatty acids come from the fat of cold-blooded animal,

fish liver oil and plants. Unsaturated fatty acids have a distinct odor because it can easily bond with

oxygen atoms in the air. Unsaturated fatty acids will react with hydrogen which is the main method of making margarine.

The amino acids which the body needs are the ones that the body cannot synthesize itself, so the body must receive them from external nutrients. Most fats coming from plants are unsaturated fatty acids e.g.

Oleic acid (C18H34O2) is found in olive and peanut oil

Linoleic Acid (C18H32O2) is found in sunflower, corn and safflower oil.

The advantages of unsaturated fatty acids to the body are

(1) a healthy body

(2) body growth in children

(3) healthy skin

(4) decreased blood cholesterol levels.

If the body lacks fatty acids, it will stop growing and the skin might become inflamed. Fatty acids are a high energy nutrient. A gram of fat will give 9 kilocalories energy. Fatty acids also help to absorb vitamin A, D, E, and K. If the body lacks fatty acids, it will also lack the vitamins A, D, E and K.

Triglyceride is an ester derived from three fatty acids and glycerol.

Things to remember

(1) The melting point of saturated fatty acids depends on the amount of carbon and hydrogen atoms in 1 molecule.

(2) The melting point for unsaturated fatty acids will be higher when the amount of carbon atom stays equal but the number of hydrogen atoms increases.

4. Vitamins - are necessary for our body because they will help the body to work normally. Vitamins have to come from food because our body cannot produce or synthesize them.

(1) Vitamin that is soluble in oil or fat is vitamin C. This vitamin will break down easily when in light or heat. So it is not accumulated in the body. If the body gets overdose vitamin C, it will cause an allergy.

(2) Vitamins that are soluble in water are vitamin B and vitamin C. These vitamins will break down easily when in light or heat. So they are not accumulated in the body. If the body gets overdoes,they will be excreted through urine or sweat.

1. Vitamin A is found in meat, milk, egg yolk, butter, fish liver oil, vegetable and fruit, especially in yellow fruits such as papaya, pumpkin etc. The benefits of vitamin A are as follow.

· Helps to maintain healthy eyes.

· Helps to build teeth enamel.

· Help to refresh the skin and not form scales.

Disadvantage of vitamin A in overdose can cause feeling queasy, hair fall and skin itching.

2. Vitamin D is found in fish liver oil, egg yolk, butter. Our body can synthesize it by using sunlight. The advantages of vitamin D are as follows.

· Control the amount of calcium in the blood.

· Help to prevent rickets.

· Help to build strong bones and teeth.

Disadvantage of vitamin D in overdose may cause feeling queasy, decreasing weight, frequent urination, constipation and high calcium levels in the blood.

3. Vitamin E is found in the oil of vegetables, e.g. grain, dark green vegetable, bean and milk. It has the following advantages.

- Prevent becoming sterile and miscarriage.

- Prevent the muscle from silting and muscle weakness.

- Prevent the blood from being destroyed.

4. Vitamin K is caused by the synthesis of intestinal bacteria from green and yellow foods such as cauliflower, soybeans, cabbage and tomato. The advantage is to help production of prothrombin by the liver and to help in blood coagulation. If the body lacks vitamin K, the blood will clot slowly. A newborn does not have intestinal bacteria to produce vitamin K. If they are wounded, they may bleed to death.

5. Vitamin B1 (Thiamine) is mostly found in coarse rice, meat, beans, rice straw mushrooms, sesame seeds, rice bran, yeast and the green leaves of vegetables. If you lack vitamin B1, you may get beriberi, become bored with food and moody.

6. Vitamin B2 (Riboflavin) is mostly found in liver, kidney, heart, fish's roe, white egg, bean and shoots of vegetables. If you lack vitamin B2, it may cause canker sore, skin rash and headache.

Advantages of vitamin B2

- Help to build red blood cells.

- Help to metabolize protein and carbohydrate.

- Help to nourish the skin.

7. Vitamin B12 (Cobalamin) is mostly found in milk, cheese, egg, shell, pickled fish and shrimp paste. The advantage is to prevent the nervous system and anemia.

8. Vitamin C (Ascorbic acid) is found in fresh vegetable, sour fruit and growing plants such as bean sprouts, top of gourd. The advantages are as follow.

- Prevent scurvy

- Help to strengthen the wall of blood vessels.

- Help to absorb other nutrients.

- Help to refresh the body.

5. Mineral Salt -does not give energy to the body but supports the cells and some organs to work normally. Some minerals needed are

(1) Calcium is found in vegetables, dried shrimps, tiny freshwater shrimps and frogs.

The advantages are

1. Build material of bones and teeth.

2. Help to control the heart and nervous system.

3. Help the blood to clot.

If the body lacks calcium, it will be rickets which will show obvious symptoms because calcium deficiency disables blood coagulation and if wounded bleeding will stop slowly.

(2) Ferrum is mostly found in liver, heart, meet, bean and some of green vegetable such as lead tree, spinach and morning glory. The advantages are

1. Reproduce red blood cells.

2. Prevent anemia. Pregnant or menstruating woman

should get a lot of ferrum to produce new blood.

(3) Iodine is mostly found in seafood such as shrimp, shell, crab and fish. The advantages are it helps the thyroid gland to produce hormones necessary to control the body’s metabolism. Children who lack iodine may not grow and become dwarfish. Some medicines and cabbage will interrupt the operation of thyroxine, a hormone secreted by the thyroid gland.

(4) Potassium is found in meat, milk, egg and green vegetable. The advantage is to control the muscle and nervous system.

6. Water - is the most important nutrient and living things cannot be without it because our body consists to 70% of water.

Advantages of water

(1) Makes the skin look fresh.

(2) Helps to nourish the body parts involved in movement.

(3) Helps to eliminate waste from the body.

(4) Helps to maintain the body temperature.

(5) Helps to digest and transport the food.

Proportion of the nutrients our body needs.

(1) The daily energy needs of the body depend more or less on:

Gender: a man will need more energy than a woman.

Age: teenagers will need more energy than kids and elderly.

Occupation: a person who does hard bodily work will need more energy than a person who works sitting at a table.

Weight: a person who lives in a low-temperature area will need more energy than a person who lives in a high temperature area. Under regular circumstances, a student will need about 44 calories per kilogram per day.

(2) A person who wants to lose weight but doesn't want to stop eating should reduce consuming high energy food rich in carbohydrates and fats and replace it with other nutrients.

(3) When consuming food follow the nutrition recommendations to satisfy the body’s need to provide nutrient in the proper amount.

- only 2-3 grams/1kg of body weight/day of carbohydrates should be consumed

-1 gram/1kg of body weight/day of protein should be consumed

-2 grams/1kg of body weight/day of fat should be consumed, in low-temperature areas the amount of fat consumption might be increased to store extra energy.

(4) High quality protein is made of 8 kinds of amino acids. These amino acids are essential for the body to function. We need them in proper proportion and appropriate for the body. All of 8 kinds of amino acids are from animal food stuff.

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