background: during the complementary feeding period, infants shift from a daily protein intake (pi) of 1 g/kg body wt to an intake 3-4 times as high. a high pi probably has both endocrine and physiologic effects and may increase the risk of obesity.
objective: we examined the associations between pi in infancy and body size and composition in late childhood.
design: we conducted an observational cohort study of 142 danish healthy term infants (63 boys) born during 1987-1988. at 9 mo of age, diet, weight, length, skinfold thicknesses, insulin-like growth factor i, and serum urea nitrogen were determined. at 10 y of age, 105 children (51 boys) participated in a follow-up study. diet, weight, height, skinfold thicknesses, percentage of body fat (dual-energy x-ray absorptiometry), insulin-like growth factor i, and serum urea nitrogen were determined.
results: at 9 mo of age, pi (in g/d and percentage of energy) was strongly correlated with body size (length and weight) but not with measures of adiposity. pi at 9 mo of age was positively associated with height and weight but not with percentage of body fat at 10 y of age. inclusion of parental body size in the models did not change the associations, but the significant associations were attenuated when body size at 9 mo of age was included.
conclusions: pi in infancy seems to stimulate early growth. this might explain part of the association between early pi and body size at 10 y of age, but a continuous effect of protein on growth during childhood cannot be excluded. pi in infancy was not associated with any measure of body fat at 10 y of age.
【关键词】 proteinadiposity hypothesis infancy childhood breastfeeding growth obesity insulinlike growth factor i protein intake