(e.g., NCHS, 1983; USDA, 1988). Such data may be useful in identifying potential nutrient inadequacies in selected groups.
Following are four examples of groups whose diets, on average, have nutrient densities lower than the values shown in Table 9-3. An energy intake of 2,200 kcal was assumed when calculating recommended nutrient densities.
Diets of adolescents (aged 15 to 17) typically contain less iron (an average of 5.7 mg/1,000 kcal) (NCHS, 1983) than recommended during lactation (6.8 mg/1,000 kcal).
Diets of adolescents with family incomes below the poverty level have a low vitamin A content (1,500 IU/1,000 kcal) (NCHS, 1983) compared with a desired density of 1,950 IU/1,000 kcal.
On average, the diets of black women contain about 30% less calcium, 20% less magnesium, and 20% less vitamin A than average diets consumed by white women (USDA, 1987).
Diets of low-income adult women are characterized by lower densities of calcium and vitamin A than are typical of diets of women above the poverty level (NCHS, 1983).
Thus, special care should be taken to ensure that breastfeeding women in such groups have access to a nutrient-dense diet.
Women with restricted eating patterns will have undesirably low intakes of certain nutrients. This applies to those whose total food and energy intake is low (unless nutrient density is unusually high) and to those who avoid foods that are major sources of nutrients, such as calcium-rich dairy products, vitamin D-fortified milk, animal foods (for vitamin B12), or fruits and vegetables (for folate and vitamin C).
In some cultural groups, beliefs regarding foods that should not be consumed by lactating women may affect dietary patterns (Baumslag, 1986), but the influence of restrictive food beliefs on nutrient intake is not well documented.
Numerous food guides for lactating women have been developed by various state and national agencies concerned with maternal nutrition. There is considerable variability in the dietary recommendations provided in these guides, as illustrated by the number of daily servings they recommend from each of the food groups (Table 9-4). For example, the recommended amount of protein-rich foods ranges from 4 to 12 oz/day, suggested servings of milk vary from three to six per day, and servings from the bread and cereals group range from four to eight per day. Some of the guides specify subcategories of fruits and vegetables, such as ''vitamin C-rich," "dark green leafy," and "other," whereas other guides lump all fruits and vegetables together and specify three to six servings.
The foods selected from within each food group can strongly influence the