A Compendium of Nutritional Status Studies and Dietary Evaluation Studies Conducted in the United States, 1957–1967

Abstract

Regardless of the difficulties of evaluation, certain inferences with relation to the nutritional status of the population do emerge from the results of studies cited in this paper. There are indications that nutritional deficiencies do occur in certain age groups and in certain areas of the country. A large number of the studies cited here were done on low income groups; therefore, implications do not apply to the total population of an area. Figures 1 and 2 indicate areas of the United States in which studies using biochemical or clinical analyses have been conducted. In many studies, hemoglobin or hematocrit levels, or both, were the only parameters measured. Figure 1 gives the location of studies which involved determinations of these levels. There was a high percentage of anemia in preschool children and pregnant women studied, regardless of geographical location. There was a higher percentage of anemia in Negro children than in Caucasians, even when all subjects were from the lower socio-economic level. In figure 2, studies involving vitamin nutrition status are indicated. If more than 10% of the subjects were deficient, or more than 20% had low blood or urinary levels of a nutrient, as judged by ICNND standards or by standards set up in the laboratory conducting the study, it was considered an indication that dietary intake was low in the group studied. The only thorough studies have been done on Blackfeet and Fort Belknap Indians in Montana, inhabitants of villages in Puerto Rico and Alaska, adolescents in Iowa and Syracuse, New York, preadolescents in New York City and Boston, older people in Syracuse, Negro migrant workers in King Ferry, New York, and hospital patients in Jersey City, New Jersey. The Montana Indians had low blood or urine levels of one or two vitamins. There were high percentages of Puerto Ricans with low intakes of one or two vitamins. Adolescents appeared to be fairly well nourished. Some Alaskan subjects had low serum vitamin A and ascorbic acid levels. Older people in Syracuse, hospital patients in Jersey City, and Negro migrant workers in King Ferry had low blood or urinary levels of two vitamins. Figure 3 shows locations of dietary studies reviewed in this paper. Results of the 1965 Household Food Consumption Survey indicated that 50% of the families in the United States had diets supplying all the recommended allowances of calories and seven nutrients, and 20% of the families had diets providing less than two-thirds of the recommended allowances for one or more nutrients. Because it would seem undesirable for any population group to have a higher percentage receiving less of the recommended allowances than those reported in the nationwide Household Food Consumption Survey, the following arbitrary guidelines have been employed to designate indications of low nutrient intake which may be critical. In figure 3 the subjects in the dietary evaluation studies reviewed here are designated as having diets low in a nutrient if 1) more than 50% of the subjects had less than the recommended allowances, 2) more than 30% had less than three-fourths, 3) more than 20% had less than two-thirds, 4) more than 10% had less than one-half, or 5) the average nutrient intake was below the recommended allowance. On this basis, studies in which subjects had low intakes of none, one or two, or three or more nutrients are located on the map. In the majority of the studies there was a low intake of three or more nutrients. The quality of nutrition observed in both nutritional status and dietary evaluation studies was generally related to economic status and level of education. The foods most needed to improve diets were milk, citrus fruits, and green and yellow vegetables.