ABSTRACT
The 20th century has certainly been an epoch for science in general. Along with great strides in so many disciplines, the expansion of nutrition knowledge has been astounding. At the beginning of the century, work conducted on food and food components was carried out by only a handful of scientists. As the century progressed into the first few decades of the 20th century, many of the vitamins were discovered, their structures defined, and syn thesis techniques developed. The metabolic mechanisms of macronutrients, namely, pro teins, lipids and carbohydrates, as well as energy metabolism in general became the subject of intense research. Furthermore, efforts for defining the requirements for the essential amino acids were taking place. The scientists who carried out such research came from a wide variety of disciplines including organic and inorganic chemistry, agricultural chem istry, physiological chemistry, medicine, and animal sciences. Some of the initial assess ments of the energy content of foods were performed by Atwater at the Agriculture Experiment Station in Connecticut. Today, a bomb calorimeter is utilized to combust foods and food components to determine their energy content (Figure 20.1)
Much of the stimulus for nutrition research at the beginning of the century was simple curiosity and the love of science by men and women. The involvement of the federal gov ernment became more evident during World War II, and was partially motivated by the high rate of rejection of military conscripts due to nutrition-related conditions. This obser vation led to the establishment of the first Recommended Dietary Allowances (RDA) for the U.S. in 1941. After that the RDAs continued to be modified and formed the impetus to continue Federal involvement with nutrition research. However, long before the first RDAs were established, federally sponsored research in nutrition was occurring through the sys tem of land grant institutions created by the Morrill Act. Modem nutrition evolved from the agriculture, medical, and basic sciences into a discipline of its own. Therefore, nutrition as a science may be viewed as a relative newcomer, but one that has certainly left its mark on the scientific community. The "father of nutrition," E.G. McCollum, introduced the lab oratory rat as a useful model in scientific research. Poultry scientists used chicks as a research model and as such made contributions to medical sciences. Much of the research on fiber began with animal scientists studying forage and feeds of livestock.
