NUTRITION OF THE BREAST-FED INFANT FROM THE SECOND WEEK TO WEANING In the beginning of the second week, as a rule, the disturbances in the infant incident to its birth have disappeared. The intestinal tract has adapted itself to the new conditions and lactation is well estab lished. Under normal conditions the technic of feeding changes very little during the next months, and this is simple enough, since we may grant the healthy infant its freedom in regard to the amount of its meals, which it usually takes with a surprising regularity. A certain control is necessary, nevertheless, particularly the continued observation of the weight and of the number and character of the passages. This enables us to recognize without difficulty excessive or insufficient in gestion of milk and peculiarities of its chemical composition: and that mostly at a time when severe injuries are still to be avoided.
Observations on numerous healthy breast-fed infants of the same age have shown that the amount of milk taken in 24 hours may vary to a certain extent with the individual infants, and within short intervals of time, corresponding to the difference of the body weight, the activity the composition of the milk, etc. Variations and differences of several hundred grains may occur, but as a rule the values are not far re moved from an average figure. The average amount of milk taken in 24 hours is: The following rule furnishes approximate figures, sufficiently accu rate for all practical purposes: To insure proper growth and develop ment the infant requires daily an amount of mother's milk equal in the first quarter year to one-sixth, in the second quarter year equal to one seventh, and in the third quarter year equal to one-eighth to one-ninth of its body weight.
While the absolute amount of milk taken increases, at first rapidly and later slowly, the relative amount decreases in the second quarter and still more in the third. The reasons for this phenomenon have been given above.
The absolute and relative ingestion of proteid may he calculated from the figures given in Table 1S, assuming that the milk contains 1 per cent. proteid.
A similar calculation of the quantities of fat and of milk-sugar is of less interest and offers more difficulties. The knowledge of the amount of energy supplied to the infant is more important. Exact knowledge . in an individual case requires a careful calculation of the amount of milk taken in 2-1 hours, and a. direct determination of the combustion value of the milk or an analysis of the milk. It is sufficient for practical purposes to calculate the energy supplied, taking as a basis a content of 700 calories per litre. The energy supplied per kilo body weight (energy quotient, according to Heubner) amounts to about 110 calories in the first quarter, 100 calories in the second and 90 calories in the third.
Should the energy quotient drop much below these figures, we can not expect a proper development of the infant, except under particular circumstances. Should an infant not thrive in spite of an apparently normal supply of energy, it is probable that the composition of the milk taken deviates fnun the average composition of milk, and par ticularl• that the fat content is low. Should an infant thrive in spite of an apparently insufficient supply of energy, the very probahly is extraordinarily rich in fat.
IThring the first three months six to seven meals are taken in 21 hours, and during the second three months five to six, so that the inter vals between meals ore first three hours, and later three and a half to four hours in daytime, with corresponding intervals at night. (;teat difficulties are frequently encountered in the institution of this arrange went, because of the desire and the custom of many mothers to nurse the infant inure frequently. Infants accustomed to more frequent meals will at first express their dissatisfaction distinctly. but a rigorous ad herence to the less frequent meals and the long intervals is of the utmost importance, in view of the harm that can easily be done by too frequent meals with excessive ingestion of food.
The average size of a single meal, which varies ecnsiderably in the course of a day, is: