no studies that directly assessed the relationship between the mode of feeding in infancy and the incidence of caries.
From the fluoride concentrations in human milk estimated by the Committee on Nutrition (1985), one could project that an exclusively breastfed infant would consume only 0.012 mg of fluoride per day. Fluoride levels are not easily increased by maternal dietary or supplementary fluoride (see Chapter 6). The only other likely source of fluoride in the infant's diet is water. The subcommittee supports the recommendations of the American Academy of Pediatrics that infants receive 0.25-mg fluoride supplements daily if their water supply contains less than 0.3 ppm of fluoride (Committee on Nutrition, 1986).
Historically, growth has been used as the basis to judge the adequacy of nutrient intake by the infant. A major question before the subcommittee was whether nutrition of the lactating woman influences infant growth. Because slow infant growth is sometimes used as a reason for supplementing infants with formula or solid foods or for discontinuing breastfeeding, it was essential to include a brief review of the assessment of infant growth. Interrelationships among infant growth, other indices of development, and maternal nutritional status were found to be difficult to ascertain, since few sound studies had been conducted to address them.
Although the most commonly used indicators of infant growth have been body weight and weight gain, it is desirable to consider simultaneously length in order to assess linear growth and adiposity (the relationship of weight to length, also indicated by skinfold thickness).
Healthy, full-term infants lose an average of approximately 5 to 8% of their body weight during the first week after birth; the percentage lost is somewhat higher among breastfed infants (7.4%) than formula-fed infants (4.9%) (Podratz et al., 1986) but is unlikely to be of clinical importance. After the first week, the pattern of weight gain in infancy depends on the initial size of the infant, whether the infant is breastfed or formula fed, and other environmental and physiologic factors. In industrialized countries, the rate of weight gain of breastfed infants is similar to that of formula-fed infants and to National Center for Health Statistics (NCHS) reference data for infants up to age 2 to 3 months; however, it is less rapid over the subsequent 9 months (Chandra, 1982; Czajka-Narins and Jung, 1986; Dewey et al., 1990a; Duncan et al., 1984; Forsum and Sadurskis, 1986; Garza et al., 1987; Hitchcock et al., 1985; Saarinen and Siimes, 1979b; Salmenperä et al., 1985; Whitehead and Paul, 1984). In developing countries, breastfed infants tend to grow more rapidly than their formula-fed counterparts