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NUTRITION AND NUTRIENTS
Proper nutrition is required to keep our bodies healthy. It is therefore important to eat the right amounts and the right kind of foods to stay healthy. Nutrition refers to the process through which living things obtain and use food. We will now study the nutrients (the compounds found in food); the manner in which our bodies use the nutrients; and the relationship between food, health, and disease.
Carbohydrates
Carbohydrates are the main energy sources. All foods give us energy but carbohydrates are the most readily available and cheapest sources of energy. Carbohydrates are of two types; complex carbohydrates and simple carbohydrates. Simple carbohydrates give us quick energy. Complex carbohydrates are first converted to simple carbohydrates during digestion.
Sugars are carbohydrates (simple carbohydrates). Their digestion and absorption are quick hence a source of quick energy. Table sugar and fruits contain sugars. Plants make food and store it as starch. Starch is a complex carbohydrate. Its digestion is slow and thus energy is released over a long time.
Fats
There are different types of fats. Fats are used by our bodies as an energy store. Fats are mainly stored around vital organs like kidneys and heart, and under the skin. Fats stored in our bodies also help in keeping them warm.
Fats from animal sources can be found in butter, cheese, eggs, milk, and meat. These are referred to as saturated fats. Nuts like cashew and almond; and oils like coconut and sesame contain fats from plant sources. These fats are known as unsaturated fats.
While fats are important for our bodies, eating too many fats or food rich in fats can be harmful.
Proteins
Proteins help our bodies to grow. They also help to repair worn out and damaged parts of the body. The following are examples of the major sources of protein in our diet: meat, eggs, fish, milk, nuts, and pulses such as beans, peas, and grams.
Vitamins
Vitamins are important for growth, keeping our bodies healthy and fighting diseases. They are required in small amounts. The vitamins needed by the human body are vitamins A, B, C, D, E, and K.
Minerals
The minerals, like the vitamins, are needed in small quantities. They help with the proper growth and functioning of the body. Examples of minerals that our bodies need include iron, sodium, calcium, iodine, and potassium.
Water
Water makes up approximately 70% of our body weight. Most of the water is found in the cells. Some water is found in the spaces between cells. Water is also present in the liquid part of the blood called plasma. Life processes cannot take place without water.
Functions of water
Roughage
Roughage (also known as fiber) is the substance in food from plants that cannot be digested by our bodies. Roughage has no nutritional value. It is mainly found in vegetables, fruits, and cereals. This fiber stays undigested, and it helps in excretion. If you do not eat enough roughage, you may suffer from constipation.
BALANCED DIET
The amount and type of food or drink, consumed in a day by a person, constitutes the person’s diet. A diet should have carbohydrates, proteins, vitamins, fats, minerals, water, and fiber in proper amounts. Food that contains all the necessary nutrients and in the right quantities makes up a balanced diet. A balanced diet promotes the proper growth of the body and protects it against diseases.
A person’s diet is also dependent on the age of the person. During childhood, the muscles and bones are growing. This needs energy and body building material. Children, therefore, need a carbohydrate and protein-rich diet.
Our daily diet is also dependent on the type of work that we do. For example, someone working in a bank and does little physical activity uses less energy and therefore needs less amount of carbohydrates. A laborer shifting heavy loads needs food rich in carbohydrates.
DEFICIENCY OF NUTRIENTS
Improper nutrition can lead to malnutrition. It is caused by an unbalanced diet. A shortage of nutrients in the diet makes our bodies unhealthy and prone to diseases. Deficiency diseases are caused by a lack of some nutrients in food.
Deficiency of carbohydrates
Carbohydrates are the main energy sources for the body. When we eat low amounts of carbohydrates, we lack enough energy. People suffering from carbohydrates deficiency feel weak, tired, hungry and confused.
Deficiency of proteins
Protein deficiency leads to severe malnutrition, especially in children. Kwashiorkor is a disease caused by protein deficiency. Its prevalence is higher in children. Marasmus is a disease that mainly affects children, but may also affect adults, caused by the deficiency of proteins, fats, and carbohydrates.
Deficiency of vitamins
Some of the major diseases caused by the deficiency of different vitamins are discussed below. It is important to note that these symptoms can be a result of other conditions.
Deficiency of Vitamin A can lead to night blindness, causing poor vision.
Deficiency of Vitamin B may result in Beriberi, a disease that causes weight loss and weakening of muscles.
Deficiency of Vitamin C leads to Scurvy which leads to bleeding of the gums.
Deficiency of Vitamin D may cause Rickets in children. Their bones become weak and soft.
Deficiency of minerals
Deficiency of minerals like Calcium leads to bone and tooth decay.
Deficiency of iodine may lead to goiter. This makes the thyroid gland (in the neck) to swell.
Iron deficiency may cause Anaemia. It is marked by paleness and low energy levels. Lack of iron in the blood decreases hemoglobin thus decreasing the oxygen-carrying capacity of the blood.
