Growth and nutrition of infants. The influence of diet and other factors on growth.

Abstract

A longitudinal study was conducted on growth and food intake of 67 unselected healthy, full-term infants from 2 to 15 months of age. The length and weight progress of infants in the study was, during the first year of life, very similar to progress as reported in an earlier study by other investigators, indicating that no striking change in size of 2-to-12-month-old infants had occurred in this area during 30 years, despite changes in feeding practices. The study infants had high calorie and very high protein intakes as compared with Recommended Allowances of the National Research Council. The question of whether some of the very high intakes seen in this study could be potentially harmful or at least beyond the range of optimum nutrition was raised. The desirability of establishing nutritional ceilings was considered. The correlation between length increment and calorie or protein intake was not significant. The correlation coefficients between weight increments and calorie intake were significant but low, indicating that other variables beside food intake influenced size and speed of growth. The correlations between iron intakes and hemoglobin levels and between fat, protein, and calorie intakes and cholesterol levels were not significant. Individual case studies indicated that the most important variables in the energy balance, beside food intake and growth, were illness and physical activity. Environment affected the balance indirectly inasmuch as it influenced physical activity.