Food is one of the basic necessities of life. It provides nutrients—substances essential for growth and repair of body tissues and regulation of vital processes. In addition, food provides energy. People choose foods from a variety of sources. Some foods contain high levels of sugar, salt, and fats, which can cause health problems if eaten in excess.
During prehistoric times, people hunted animals and collected wild plants for their food. Over time, they began to cultivate crops and raise domesticated animals. The development of agriculture and animal husbandry allowed people to grow large quantities of food and have a regular supply of it. It also led to the creation of new foods, such as breads and sauces made from wheat, rice, and barley.
Diets vary widely from one country to another and even within a country, depending on such factors as the availability of certain foods and the climate. For example, people living in cool regions with short growing seasons may prefer root vegetables such as potatoes. They also may eat more fish than people in warm, wet lowlands because of the abundant supply of seafood.
In addition to a diversity of foods, a well-balanced diet must include adequate amounts of vitamins and minerals. A person needs carbohydrates for energy, as well as proteins to build cells and tissues and to promote growth. Fats provide double the amount of energy as carbohydrates and help to insulate and protect body organs. People obtain fats from plant oils, such as olive, cottonseed, and peanut oil; from the seeds of some nuts, such as almonds and walnuts; and from animal products, such as butter, lard, and eggs.
Eating habits are strongly influenced by culture. Many people follow religious dietary restrictions or have social traditions that influence what they eat. For example, Jewish people must follow kosher, or kashrut, law when preparing and consuming food.
A person who enjoys food and is interested in the preparation, industry, or history of food is a foodie. He or she often cooks and eats at restaurants, but does not usually work in the restaurant business. Foodies can be amateur or professional chefs, cooks, or food writers.
People who care about the quality of their food try to eat organic or local foods. They may buy meat from cattle raised on grass pasture rather than fed grain in feedlots. In addition, they often prepare meals using fresh or frozen produce and avoid canned and boxed foods that contain added salt and sugar. They may be concerned about the effect of chemicals in processed foods on their health and the environment. They also often seek out organic, fair-trade, and sustainable seafood.