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OCR for page 238
GILBERT A. LEVEILLE Commentary In the United States, as in most developed nations, the rise in affluence has been accompanied by increased consumption of foods of animal origin- meat, milk, and eggs-largely at the expense of cereals and potatoes. The effect of this dietary change has been an increase in the proportion of calories derived from fat and protein intakes exceeding needs by a substantial amount. These changes, along with programs of fortification, have led to marked improvements in the nutritional state of most citizens. However, in view of changes in the world about us and the increase in our knowledge concerning nutrition and health, it is appropriate to raise questions regarding the desirability of our present diet. The total fat content of American diets has risen in recent decades to approximately 45% of total calories. About one third of the fat in American diets is of animal origin. It has been suggested that this high intake of animal fats may be associated with an increased incidence of cardiovascular disease in the United States. However, the supporting evidence is inconclusive and is not adequate to warrant recommenda- tions for a change in the U.S. diet. One of the major diet-related prob- lems in the United States is obesity. A high proportion of Americans are overweight to a significant degree. Consequently, a reduction in the caloric intake of most Americans would be desirable. This could most effectively be accomplished by reducing our intake of fat, either by reducing our consumption of foods supplying a large proportion of calories as fat, such as meat, by selecting similar foods containing less fat, i.e., leaner cuts of meat, or by producing meat animals containing less fat. 238

OCR for page 238
Commentary 239 Epidemiological studies and the results of preliminary investigations suggest that an increased consumption of dietary fiber (derived from cereal grains, legumes, fruits, and vegetables) may be important in preventing diverticular diseases, cardiovascular disease, and perhaps colonic cancer. Clearly more experimental data is required before definitive recommendations are possible. However, it is reasonable to recommend that cereal, fruit, and vegetable consumption should not be further decreased and hence that further attempts be made to maintain present consumption levels of animal foods. These animal foods de- sirably would be lower in fat. This symposium has reviewed the avail- able information, which indicates that indeed the level of fat in the carcasses of meat animals can be reduced. Animal feeds account for approximately 75% of the corn used in the United States. A high proportion of oilseed meals likewise are used for animal feeds. It is estimated that approximately 2,000 lb of cereals per capita are used in the United States primarily for animal feeds. This compares to approximately 400 lb per capita consumed in the develop- ing world. Some hate suggested that the citizens of the United States should reduce their meat consumption and thereby make the cereals saved available for export to food-deficit countries. Such suggestions have met with generally negative reactions on the part of many. It is argued that citizens of this country should not be asked to lower their "standard of living" to aid the less-fortunate part of the world. There is no simple resolution to the dilemma posed. However, it should be recognized that animal agriculture does represent an important industry that contributes significantly to the quality of the American diet. Perhaps the question which should more appropriately be raised is whether animal foods can be produced more efficiently, i.e., using less cereal grains and oilseeds, and thereby provide a greater quantity of these products for export without any marked reduction in per capita con- sumption of animal foods. The reports presented during this symposium indicate that indeed this is possible. Meat animals can be produced that contain less body fat and yet provide nutritious, acceptable products. Eliminating the conversion of the energy of cereals and oilseeds to animal fats does not deprive American consumers; in fact, nutritionally more-desirable products are provided. Increased efficiencies of production are also possible through genetic selection and improved management techniques. These are to be en- couraged, as they also will result in a reduced need for cereal grains in animal production and the provision of nutritionally more-desirable food products.