A substance that provides the energy and nutrients needed for growth and maintenance of an organism. Most plants and some animals obtain food by consuming other organisms or organic matter. Plants and some algae make their own food by photosynthesis; animals obtain it from other living things or from substances produced by them. Food is ingested by an organism and absorbed through the digestive system. It serves several purposes, including providing fuel, building body tissues, and regulating various vital functions. A lack of accessible or palatable food may lead to malnutrition, starvation, or death.
The selection, preparation, and serving of food are strongly influenced by culture. Rituals surrounding the eating of food serve social and cultural functions as well as biological ones. Food is also a source of pleasure, and people enjoy foods they consider to be tasty and satisfying.
Foods vary widely across the globe, reflecting local traditions, climate, and available resources. A person’s diet may also be shaped by their socioeconomic status, ethnicity, religion, and age.
People’s choices about what to eat are complicated by the fact that many foods are both healthy and unhealthy. A diet high in fruits, vegetables, whole grains, and lean proteins can help a person maintain good health. A diet low in added sugars, salt, and saturated fats can help a person manage his or her weight.
Eating habits are formed early in life and may be difficult to change. Children who are fed a diet of mainly processed foods are more likely to have poor health in adulthood than those who eat a variety of nutritious foods.
The type and amount of food a person eats may be affected by his or her cultural background, the availability of certain foods, and beliefs about how food should be prepared and eaten. For example, some cultures value bland tastes while others treasure a wide range of spices and flavors.
Foods are grown, raised, and processed to meet the nutritional needs of individuals around the world. They are an important part of the economy and a major source of employment. The production, processing, distribution, and consumption of food involve complex systems, such as those of water supply, waste management, agricultural policy, and global trade. The study of these systems is called food science. It is a rapidly growing field that combines elements of biology, chemistry, mathematics, engineering, and technology to improve the quality and safety of food. It also offers new opportunities for the development of processed foods that are less expensive and easier to prepare than fresh foods.