PACKET FOOD
A limited selection of food that is prepared in advance and within minutes of being ordered is known as fast food, and fast-food restaurants are popular eating places in most populated places in the United States. For many decades there have been hot dog, hamburger, and other snack stands that offer almost-instant meals. Modern fast-food establishments, however, differ from both the restaurant and such snack stands in that most of them belong to chains of franchise outlets. This enables them to offer a great number, yet still limited selection, of dishes at nominal prices and still make an adequate profit.
Because they are chains, the food they sell is virtually the same at every outlet, and they generally specialize in one kind of food such as hamburgers, pizza, chicken, or tacos. This specialization and standardization is maintained by the terms of the franchise agreement, which requires every outlet to offer the same type of service and to buy its inventory from approved wholesalers. Some chains, however, have begun to diversify. McDonald's, for example, has experimented with pizza, fried chicken, and submarine sandwiches, and many restaurants now serve breakfast.
Apart from immediate service and standardized products, fast-food establishments differ from other restaurants by selling food over a counter. There may be tables, and the food may be eaten on the premises, but customers are not seated and offered a menu. There are restaurant chains—such as Shoney's, Red Lobster, and Denny's—that provide quick service and standardized menus, but they operate more like regular restaurants in that they provide table service and offer a wider range of food and beverages. Dining in these establishments is generally a more leisurely experience than that offered by fast-food outlets, and they are also more expensive.
Most fast-food meals are high in fat and sodium and low in fiber and nutrients. Although consumers may choose chicken or fish entrees as lower-fat alternatives, fried patties and nuggets may derive more than 50 percent of their calories from fat, well over the 30 percent recommended by public health organizations. Some chains provide reduced-fat hamburgers, salads, low-fat milk, and juices.
Although some fast-food operations—White Castle hamburgers, for example—have been in business for several decades, the great growth in these establishments took place only after World War II. Two of the largest companies, McDonald's and Kentucky Fried Chicken, were founded in 1955. By the early 1990s there were more than 500 food franchising companies with a combined total of more than 70,000 retail outlets in the United States. Of these outlets about 48,000 are owned by franchisees, while 22,000 are owned by the companies and leased to operators. McDonald's owns all of its outlets; some companies sell their franchises; others, such as Kentucky Fried Chicken, both sell and lease.
While McDonald's and a few other food franchising companies remain independent corporations, most companies have been bought by larger firms. Burger King, for example, is owned by a British corporation, Grand Metropolitan PLC. Pizza Hut, Kentucky Fried Chicken, and Taco Bell are all owned by Pepsico, Inc.
American-style fast-food emporiums have appeared around the globe. Of the more than 4,000 foreign outlets, most are in the United Kingdom, Western Europe, Japan, Australia, and New Zealand. In the late 1980s American fast-food companies began establishing outlets in Communist nations. Pizza Hut opened a branch in the Soviet Union in 1990, and by 1991 the McDonald's in Moscow's Red Square, serving 27,000 customers per day, had become more popular with tourists than Lenin's tomb.
OLESTRA
Olestra, was developed by Procter & Gamble as a replacement for fat in foods. Although the components of olestra—sucrose (table sugar) and fatty acids—are naturally occurring substances, the product itself is synthetic. Despite its approval in 1996 by the United States Food and Drug Administration (FDA) for use in salted snack foods, olestra drew heavy criticism from consumer-advocate groups because of reports by consumers of gastrointestinal malaise following consumption of products that contained olestra. Further scrutiny by medical researchers revealed that olestra interferes with blood levels of many important fat-soluble substances including carotenoids, which have been associated with lowered risk of heart disease and some cancers.
Olestra was discovered in 1968 by two Procter & Gamble researchers who were studying fat digestion. Their investigations led to the identification of a fat-like substance that was not degraded and digested by the body. The substance was originally called sucrose polyester, because its components of sucrose and fatty acids were chemically bound by ester bonds. The chemical name of the substance was eventually changed to olestra, and the corporation began conducting studies to examine what, if any, changes occurred when the substance was used as a cooking oil. Although not the first fat replacer discovered, olestra was the first that did not break down when used at high temperatures, thus it could be used for frying.
During the 1970s, Procter & Gamble conducted numerous investigations to study the safety of, and uses for, olestra in foods. In 1987, they petitioned the FDA for approval to use olestra as a general fat substitute in snack products. At the same time, the Center for Science in the Public Interest (CSPI), a consumer-advocate group, publicly criticized the product, charging that the tests conducted by Procter & Gamble were inadequate, and that the product produced, among other things, severe gastrointestinal (GI) symptoms, including flatulence, fecal incontinence, diarrhea, and anal leakage. Furthermore, the studies had revealed that the product interfered with the absorption of important fat-soluble nutrients, such as vitamins A, D, E, and K, and many carotenoids. Procter & Gamble responded by modifying the structure of olestra, as well as supplementing it with vitamins. Although it was subsequently approved by the FDA in 1996, all products using olestra—which is marketed under the trade name Olean®—must contain a warning about the adverse effects of olestra. After its release in 1998 on the United States market as an ingredient in several popular snack foods it continued to cause GI illnesses in some people despite the modifications made by the manufacturers.
Chemically, a molecule of olestra consists of a molecule of sucrose esterified to up to eight fatty-acid residues. The large size of the molecule, as well as the large number of fatty-acids, prevents it from being metabolized by GI bacteria and enzymes. Because of its fatty nature, olestra has a strong affinity for many fat-soluble substances. Whereas natural fats are broken down and absorbed by the intestine, olestra is passed through, and along its route it absorbs many valuable nutrients such as cholesterols, vitamins, and phytochemicals such as carotenoids, lycopene, and lutein.

Chemistry
The most abundant of the fatty acids combined in fats and oils are called stearic, palmitic, and oleic. Compounds having only one acid are called stearin, palmitin, and olein. Beef tallow is rich in stearin and palmitin, which are solids at room temperature; olive oil is mostly olein, a liquid. Most vegetable fats and oils contain all three of these acids. Small quantities of various substances, including other fatty acids, give fats and oils their distinctive odors and flavors.
Fats and oils are unsaturated or saturated, depending on the way in which carbon atoms are bonded together in their molecular structure. An unsaturated oil can be made saturated by applying heat and pressure to the oil in an atmosphere of hydrogen. This process, called hydrogenation, is used to change vegetable oils to solid fats for making margarine and cooking fats.