Food is any substance consumed by an organism to get energy for various activities like movement and growth. It is usually of plant or animal origin and contains essential nutrients such as carbohydrates, fats, proteins and vitamins. Food is also a social construct; it plays an important role in defining culture and serving as a vehicle for transmitting cultural values. In some cultures, specific foods are considered auspicious or ceremonial, and may be consumed in large quantities as part of a religious or special event.
People obtain most of their food from plants. Plants are the source of all fiber, starches and some sugars. They also contain many vitamins and minerals. Humans use both wild and domesticated plants for food. Domesticated plants are more commonly used as they are easier to grow and maintain.
The main sources of meat are mammals and birds. The most common domesticated animals are cattle and pigs, although chickens, ducks, geese, quail and turkeys are raised as well. Other animals that are eaten include fish and shellfish. People can eat these animals raw or cooked. They can also be preserved by smoking, salting, canning or pickling.
Immigrants often introduce new foods to the cuisine of their host countries. In addition, improved methods of food processing, preservation and shipping allow people to enjoy foods produced far from their homes. This makes a wide variety of foods available around the world. For example, Europeans can eat olive oil from Spain, cheeses from France and sardines from Norway.
A diet rich in fruits and vegetables and low in fat is associated with a reduced risk for high blood pressure, heart disease and diabetes. High-fat foods, such as fried chicken, French fries and ice cream, are linked to higher risks for these diseases.
Most people should drink eight to 12 cups of water each day and eat foods that are high in protein, fiber and antioxidants and low in fat and sodium. These foods help keep the body hydrated and provide fuel to the cells. They can also reduce the likelihood of developing a chronic illness, such as heart disease, diabetes, obesity and cancer. People should avoid processed foods, such as those containing trans fats and added sugars. When eating out, choose healthier options, such as grilled, broiled or baked meats and fish instead of fried meats; salad with a light vinaigrette; and whole grains instead of refined foods like white bread. When cooking, try to add herbs and spices instead of salt. Baking a dish rather than roasting or frying helps to reduce the formation of harmful chemicals such as heterocyclic amines and polycyclic aromatic hydrocarbons, which have been linked to cancer. When possible, choose fresh or frozen vegetables and fruits rather than canned. When buying packaged goods, read the nutrition label to make sure that they are low in sodium and saturated fat.