Immediately after the Civil War, however, the diet began to change. 46){{U}} Rail transportation increased the supply and improved the quality of the milk that reached urban centers; cold storage and refrigerator cars made possible the greater consumption of fresh vegetables, fresh fruits, and fresh fish; and commercial canning extended the range of appetizing and healthful foods{{/U}}. Subsequently food statistics indicated an increased consumption of dairy products, fresh fruit, fresh vegetables, sugar and syrups, coffee, tea, cocoa, and spices. Decreased consumption was shown for meats, potatoes, and grain products. 47){{U}} By and large, the American diet continued to reflect a considerable reliance upon animal products: rather than on grains. which meant that a relatively large acreage was required to feed the American public{{/U}}. Whereas a grain and fish diet, such as in Japan, requires only a quarter of an acre high yield cropland and no pasture per capita, the American diet requires about two and a half acres of cropland and ten acres of pasture per capita-Also it indicated a shift toward the so-called protective foods, toward those high in vitamins and proteins. 48){{U}} This change was greatly furthered by governmental food inspection ( the Pure Food and Drug Act was passed in 1906), by the increasing, use of mechanical refrigerators in the 1920's and 1910's and of freezers for frozen food during recent decades.{{/U}}
In the years after World War I a food revolution took place that was reminiscent of the one that occurred after the Civil War. The output of the food manufacturing industry quadrupled from 1900 to 1920.49){{U}} In that interval, as we have mentioned earlier, home canning gave way to commercial canning and the labor of housekeeping was lightened.{{/U}}
Fortunately most of the major dietary changes that have taken place since the middle of the nineteenth century have resulted in better nutrition for the population. In port, these shifts have taken place because of a preference for new foods rather than old, but in part, they have been made because the new foods were advocated by nutritionists. Apparently American dietary customs were not so deeply ingrained as to prevent change in the interests of better health. 50){{U}} Possibly one factor that has contributed to the readiness of Americans to accept new foods or food preparations as the general familiarity most have with a variety of regional dishes coming from many different lands.{{/U}} Within a small area in New York City or San Francisco, one can find restaurants specializing in French, Italian, German, Turkish, Arabian, or Chinese cuisine. And at a Chinese restaurant in the United States the chef and waiter are as likely as not to he Oriental.