Fast food is food is prepared and served quickly at a fast-food restaurant at low cost. Fast food is a multi-billion dollar industry which is continuing to grow at a rapid pace in the early 21st century in many countries as fewer people cook at home.

Fast food is often highly processed and prepared in an industrial fashion, i.e., with standard ingredients and methodical cooking and production methods. It is served usually in cartons or bags in a rapid manner in order to minimize costs. Fast food outlets often provide take-away or take-out food in addition to a sit-down service. Drive-throughs allow food to be ordered and delivered without leaving the car to further speed service.

Fast food is usually finger food that can be eaten quickly and without cutlery. Fast food often consists of sandwiches, pitas, burgers, breaded chicken, french fries or pizza although many fast food restaurants offer some other less easily consumed choices like chili, mashed potatoes, or salads. Chinese cuisine, although often served as take-away, is not always considered fast food.

McDonalds is a noted company which supplies fast food. It is a phenomenally successful enterprise, in terms of financial dominance and world-wide expansion. Fast food restaurants are most popular in the United States, which is credited with developing the style. Many major international chains are based there. As a result, fast food has often been the target for opponents of globalization, the target of anti-Americanism and subject to attacks on the grounds of cultural imperialism.

This charge does have a certain plausibility if a chain offers a menu standardised in America, to customers in countries with very different cuisines. However, multinational corporations generally modify their menus to local tastes.

In addition, multinational fast food chains are not the only or even the primary source of fast food in most of the world. Most fast food in the developing world is provided by small individual mom and pop eateries. In the developing world, multinational chains are considerably more expensive, they usually are frequented because they are considered chic and somewhat glamorous and because they usually are much cleaner than local eateries.

Because of its convenience, fast food is popular and commercially successful in most modern societies, but it is often criticized for having the follwing alleged shortcomings, among others:

  • It has poor nutritional value,
  • It contributes to obesity,
  • Exploitative advertising and marketing is used (especially directed at children),
  • It causes environmental damage through excessive packaging and clearing forests for animal rearing.
  • It reduces the diversity of local cuisines

The unhealthiness of fast food comes in part from cooking methods. Fast food tends to be deep fried which increases the amount of fats and calories.

The need to limit the fast food approach is increasingly being recognised in the early years of the 21st Century. Some of the concerns have led to a Slow Food reaction. This movement seeks to preserve local cuisines and ingredients, and directly opposes laws and habits that favor fast-food choices. Among other things, it strives to educate consumers' palates to prefer the richer, more varied and more nourishing tastes of fresh local ingredients harvested in season.

Some of the large fast food chains are beginning to incorporate healthier alternatives in their menu, e.g. salads and fresh fruit. However, some people are cynical about this, seeing it as a tokenistic and commercial measure, rather than an appropriate reaction to genuine worries about the world ecology and people's health. For their part, fast food restaurants make no secret of the fact that their change in menu is not out of idealism, but rather because of the trend in the early 21st century developed world toward increased health consciousness.