Food is any substance consumed to sustain a human or animal’s life, providing energy and essential nutrients. People obtain food from the plants that grow in the fields or in their gardens, and they eat animals that they kill for meat, eggs and dairy products. People also eat raw or processed foods that are manufactured and sold in stores. Food safety is important to prevent illness from harmful microorganisms or chemicals that can be present in some foods.
The study of the chemical composition, properties and behavior of foods is known as food science. It incorporates elements of chemistry, biology, engineering, mathematics, economics and sociology. The field is rapidly expanding, as consumers demand more and better-preserved foods that can be prepared quickly and easily at home. Food scientists are addressing these demands by developing new methods of food processing, storage and preparation.
Eating habits are strongly influenced by culture, and many cultures have their own distinctive cuisines. Foods are also cultural symbols that express a people’s values, traditions and beliefs. A person’s access to food is often determined by the ability to afford it, and the cultural and geographic environment in which a person lives.
Having enough food to survive is the most basic need of all living things. People usually seek food as a response to hunger, but the concept of eating for pleasure as well as nutritional needs is universal. People also eat for enjoyment and the satisfaction of their taste preferences. Eating habits are often shaped by social and cultural practices, including rituals surrounding the preparation, sharing and consumption of food.
An essential component of a healthy diet is the avoidance of unhealthy foods, such as refined sugars and flours, processed fats (e.g., shortening and margarine) and salt. Instead, a person should eat more whole grains, fruits, vegetables and lean meats, fish and healthy oils, such as olive oil or canola oil.
To help preserve the nutrient content of fresh food, it is a good idea to cook vegetables and fruits as little as possible. Overcooking can result in the formation of carcinogenic compounds, such as heterocyclic amines and polycyclic aromatic hydrocarbons, which may cause cancer. It is also a good idea to choose organic produce whenever possible, and to soak or ferment legumes, nuts, seeds and grains to improve their digestibility and bioavailability. Finally, a person can minimize the amount of food he or she eats by controlling portion sizes.