Food is any substance eaten by living organisms to obtain the nutrients needed for survival and growth. It is usually of plant or animal origin and contains essential proteins, carbohydrates, fats, vitamins, and minerals. The substances in foods are absorbed and assimilated by the body through digestion. Animals also serve as sources of food for other organisms in the form of meat, milk, and eggs. Humans use a variety of techniques to prepare and preserve foods for consumption.
The science of dietary composition, or dietetics, examines the ways in which food choices and eating habits affect health and well-being. Dietetics is a major branch of nutrition science. A person’s diet consists of the foods and beverages he or she consumes on a regular basis. The food choices a person makes determine his or her nutritional status, which in turn affects his or her physical health and emotional well-being.
People need a variety of different foods to achieve good health. A typical modern diet includes cereal grains such as wheat, rice, barley, oats, and corn (maize); fruits; vegetables; nuts; legumes; and meat, poultry, fish, eggs, and dairy products. A person’s ability to access these foods depends on his or her geographic location and income level.
A person’s cultural identity and traditions also influence his or her preferences in foods. The cuisines of different cultures and traditions may differ significantly, but many of them have common elements, such as the use of herbs and spices. Some foods are associated with particular holidays or events, and these can become symbolic of a culture.
Many people enjoy the pleasures of food, as well as its social and psychological functions. Eating can bring joy and relaxation, and the act of sharing food strengthens family and social bonds. Foods can also evoke pleasant memories or inspire creativity.
In addition, food can provide an important source of energy. The energy in foods comes from the breakdown of complex molecules called carbohydrates, fats, and proteins. Proteins and carbohydrates are used for metabolic processes in the body, while fats are stored as a reserve fuel.
A person can reduce his or her risk of chronic diseases by consuming a balanced diet. In general, a diet rich in whole grains and lean proteins is beneficial. In addition, the amount of fat in a person’s diet should be limited.
A balanced diet can be difficult to achieve, especially in areas where processed foods are popular. A person should read labels on food packages and avoid foods containing excessive amounts of saturated fats, trans fats, or sugars. He or she should also limit intake of sodium, which can cause high blood pressure. A person who wants to change his or her diet can start by replacing unhealthy fats with vegetable oils and reducing the intake of refined carbohydrates. He or she should also eat more fruits, vegetables, and whole grains. It is also important to get enough fiber, which can help prevent constipation.