Fast food is popular the world over because it is easy, inexpensive, and filling. It appeals especially to families, busy people, and those living on their own because it is both speedy and practical. The most familiar fast foods are probably hamburgers and hot dogs, which first appeared in the United States at the turn of the twentieth century. The sandwich, which is known the world over, has been around since the nineteenth century. Different countries have different kinds of fast food, some of which, such as noodles, sushi, or falafel, are specialties of a particular culture's cuisine. Many fast food franchises have become global brands. Fast food is often equated with junk food, because it tends to be high in fat, sugar, and salt. Consuming a lot of fast food may, therefore, contribute to obesity, particularly childhood obesity. Traditional fast food does not usually equate with healthy eating guidelines, because fast food meals are low in fruits, vegetables, and fiber. Fast food may also contribute significant carbon emissions and waste. These concerns have led to an interest in slow food, which emphasizes the pleasure and traditions of food, as well as respecting the environment. Some fast food franchises have also made concessions by introducing some healthier choices and trying to cut back on packaging.

People have always eaten fast food. Stalls selling bread and wine were popular in ancient Rome, and pies and pasties were sold on the streets in Europe and elsewhere in the Middle Ages. Street food such as samosas and falafels have long been popular in India and the Middle East, respectively. But modern fast food probably began in England, with the invention of the sandwich by Lord Sandwich (1718–1792), who reportedly placed meat between two slices of bread to save having to leave his desk for dinner. The United States is often regarded as the fast food capital of the world, and it all began with the hot dog. A German butcher, Charles Feltman (1841–1910), opened the first hot dog stand in Brooklyn in 1867. The first fast food restaurant opened in 1912, in New York City. The trend soon caught on and these restaurants, sometimes known as automats, had spread around the United States by the 1920s. As cars became more affordable, drive-in restaurants became popular. The White Castle hamburger chain, set up in 1916, was the forerunner of McDonald's, which was founded as a barbecue drive-in in 1940 by brothers Dick and Mac McDonald. Burgers proved more popular than barbeque so they re-opened as a chain selling burgers, fries, and drinks in paper wrappings and cups. The term fast food first entered the dictionary in 1951.

There are many different types of fast food besides hot dogs and burgers, including crisps, pot noodles, the British favorite fish and chips, kebabs, pizza, and chicken. Fast food is available from many types of outlets, including shops, restaurant franchises, garages, and street stalls. Author Eric Schlosser (1959–) highlights the love American people have of fast food in his popular 2005 book Fast Food Nation. He points out that Americans spend about 110 billion dollars per year on fast food and one quarter of the population eats fast food every day. Fast food is popular because it saves time in preparing and cooking food; it is filling; and, above all, it is relatively inexpensive. Added to this, many fast food restaurants are clean, warm, and welcoming to families, often providing treats and playgrounds for children. Fast food also enables busy people to eat on the run. For those living alone, it is often more economical to buy takeout than cooking from scratch, because food in supermarkets generally comes in bigger packages.

Fast food has become synonymous with unhealthy food, and it is often known as junk food. Regular consumption has been blamed for rising levels of obesity. Several Page 280  |  Top of Articleresearch studies back this finding. For instance, a 15-year study of 3,000 Americans showed that people who consume fast food on a regular basis over a long time do have a greater tendency towards obesity and developing type-2 diabetes. Those who reported eating fast food meals more than twice per week weighed an average of 10 pounds more than those who rarely ate fast food. A study from researchers at the New York City Department of Health and Mental Hygiene concluded that much fast food, and fried chicken meals in particular, contains more than the recommended daily intake of salt, which increases the risk of high blood pressure.

In-N-Out Burger signs fill the skyline in Baldwin Park, California, in June 2010. Amid complaints of obesity and lines of idled cars stretching into neighborhood streets, this blue-collar town is banning new drive-throughs in hopes of shedding its reputation as a haven for convenient, fatty foods. AP Photo/Adam Lau AP Images.

Childhood obesity is a particular problem arising from fast food consumption. Reared on fast food, children learn to prefer French fries to vegetables, which are normally available only as a salad garnish on a burger. Fast Food Nation reports that teenage boys can be getting up to ten percent of their daily calories from sodas, rather than from more nutritious foods. Traditional fast foods are high in fat, salt, and sugar and, to compound the problem, are often available in large portions. But fast food need not be unhealthy. Some franchises have begun to cut salt intake in their products, and many display nutritional labels to help consumers make more educated choices. There is also an increasing interest in home cooking, slow food, buying local, and eating organic, all of which counter the fast food trend.

Fast food is linked to a number of environmental issues. In 2000, researchers at Stockholm University and the Swiss Federal Institute of Technology analyzed the various energy inputs that are associated with a single cheeseburger and concluded that it was responsible for an extra 2.2–7.7 pounds (1–3.5 kg) of carbon emissions. Fast food Page 281  |  Top of Articlealso increases the carbon footprint because of fuel consumption involved in their distribution. Finally, fast food creates local pollution problems through the amount of polystyrene packaging used. However, some companies are attempting to reduce their packaging and McDonalds, for instance, has implemented the use of recycled materials in some of its food containers. The consumer can help by recycling fast food containers such as cardboard pizza boxes.