Food is any substance consumed by living organisms for energy or nutrients. The term is used to refer to both the products of plant and animal origin as well as the activities involved in their preparation. Humans and other animals have evolved to fill specific ecological niches and require diets that reflect this. A food’s nutrient content determines its value to the organism that consumes it. Food can be prepared by a wide range of methods to produce different flavors and textures, and also to protect it from spoilage or contamination.
Most people do not grow all of the food they eat themselves, but buy it from markets or shops. The availability and types of foods depend on local conditions, including climate and soil type. People who live in cool regions with short growing seasons may rely more on fish and root vegetables than those in warm areas where there are many tropical plants that bear fruit. Diets may differ within a country according to customs and traditions.
People eat to obtain the nutrients they need for good health, but too much food can lead to obesity and other diseases. Too little food can result in malnutrition. People also eat for pleasure and to celebrate. Foods that are considered unhealthy include those with a high fat, salt and sugar content as well as processed or junk foods. Some foods are toxic to humans or animals, such as poisonous mushrooms, spoiled milk and salmonella-tainted eggs.
The study of food is known as food science, and scientists work to develop new methods of producing and preserving it. They also investigate the nature of food, its chemical composition and how it satisfies the body’s nutritional needs. Scientists aim to make safe, nutritious food available to all by improving the efficiency of production and reducing costs.
Almost all modern foods are processed to some extent. Some of the most common processing steps are washing, milling, grinding, chopping, cooking, freezing, drying and canning. Processing increases the durability of foods and often adds flavor, texture and color. Some processed foods are also convenient, as they can be eaten without further preparation. Examples are canned fruits and vegetables, certain cheeses and ready-to-eat meals.
People use food to express their cultural identities, and to share knowledge about the world. They also enjoy eating foods from other cultures, and a number of cookbooks have been written on ethnic cuisines. However, it is important not to disparage these foods by using terms such as strange, exotic or abnormal, which can cause a person to be hesitant to try them. People should also be careful not to imply that they have “discovered” an ethnic cuisine, as this has connotations of colonialism. Moreover, it is unfair to impose one’s own culinary preferences on people who do not share them. Therefore, food writing should be informative and objective. It should not be about selling a product, but rather about sharing an experience and culture.