Nutrition is the biological and nutritional process through which an organisms uses food to support its normal life. It includes absorption, assimilation, production, catabolism, degradation and elimination. The five metabolic processes are defined as follows: digestion, absorption, transportation, excretion and conversion of food into energy. Nutrition can be described in terms of five main categories, which are protein, carbohydrate, vegetable, fat and fiber. The main article will elaborate on each of these aspects. The first category, carbohydrates, includes all those molecules which are composed of sugar. These include glucose, maltose, sucrose, lactose and cellulose. Some examples of carbohydrate which are included in the nutritional groups are fruits, vegetables, grains and cereals. Carbohydrates are the most important group of nutrients for a balanced diet and for maintaining good health. The main function of these substances is to provide energy to the body. They are also responsible for storing some nutrients and vitamins. A person needs carbohydrates to meet the body requirements for energy. This article will discuss about the different types of carbohydrates. The second class is fats. Fats can be classified according to their content. The fats which can be found in foods can be classified into three. These include omega-3 fatty acids, monounsaturated fat and polyunsaturated fat. A person eats the fat from foods in order to meet the fat requirements. However, they should be limited to certain extent because excess intake can cause serious health problems. Mineral nutrition is very important for a balanced diet and is comprised of different classes of minerals like iron, calcium, magnesium, potassium, sodium, zinc and folic acid. These elements are required by the human body in order to maintain its normal functioning. The minerals can be consumed in their natural form or as supplements. Nutrition is a science that studies the relationship between a diet and nutritional intake. It studies the food groups and how they affect the different systems of the human digestive system. Nutrition considers three categories: calorie, nutrient and digestible. A diet should contain calories so that the body can use it for energy but should not cause the body to stores energy itself. Nutritional problems can be prevented by eating healthy foods that contain adequate amount of vitamins, minerals and fibers. Calorie intake should be controlled because excessive calories can cause obesity. Nutritional problems can also be caused by digestive problems. Digestive problems like diarrhea, constipation, stomach cramps, heart disease and skin problems can prevent the absorption of nutrients in the body. There are many herbs that help in the digestion process and prevent nutritional deficiencies. There is no single main article that defines the role of nutrition in the world. Each person should learn the different types of foods and nutritional values of each food group to live a healthy life. Proper diet can be learned only through constant practice and observation of the foods and nutrition methods. In this main article ӮutrientԠis defined as the proportion of one substance to another substance in a food. Nutrient values are measured by units such as calories, protein, fat, carbohydrates, fiber, etc. The consumption of nutrients determines the human nutrition. There is no main article that defines the meaning of each nutrient or how many are present in each food. However, these three main categories of nutrients are very important for the human body. These are carbohydrates, fats, and protein. Carbohydrates provide energy to the body while fats are used as sources of energy. Protein is needed for the building of muscles while fiber provides good digestion of food. It is important to eat small amounts of healthy foods to maintain the health of our bodies. We should try to eat at least six small amounts of healthy foods every day to keep our bodies in a healthy condition. Nutritional education is essential to have a balanced diet. Everybody should learn and follow the nutritional guidelines to reduce the risk of diseases. Some diseases include cardiovascular disease, cancer, osteoporosis, high blood pressure, viral and bacterial infections, and cancer. Nutritional counseling is also given to people who are following a special diet or taking specified medication. Vitamin and mineral deficiencies are common among most people. Most people do not get enough vitamin A, B1, and C which are essential for proper immune system functioning. Vitamin D is important for healthy bones and teeth. Low levels of iodine may result in hyperthyroidism and other diseases.