THE FOOD REQUIREMENTS DURING PREGNANCY
The Food-stuffs: Water; Mineral Material; Protein; Carbohydrate; Fat—
What We Do to Our Food—How Much Food Is Needed During Pregnancy?—
The Importance of Liquid Nourishment—The Choice of Food—Cravings—
The Relation Between the Mother's Diet and the Size of the Child.
There is a gain in weight during pregnancy amounting finally to about thirty pounds; exceptionally, it is as little as ten or fifteen pounds, and, at the other extreme, as much as forty or fifty. With individuals inclined to be stout the increase is greater, and it is relatively greater in later pregnancies than in the first. During the early months of pregnancy the weight generally remains stationary or suffers a slight loss; even in those rare instances in which the weight begins to increase shortly after conception the gain is less marked in the earlier months than later. For the last three months the average monthly gain has been found to be between three and a half and five and a half pounds.
The weight gained during pregnancy is not, as can be readily understood, permanently retained. At the time of birth, in consequence of the expulsion of the child, the after-birth, the amniotic fluid, and a varying amount of blood, there is necessarily a loss of from ten to fifteen pounds. Later, as the maternal tissues, whose growth has been stimulated during pregnancy, return to their original condition, a further loss in weight takes place. It is not unusual, however, for women to remain permanently better nourished than before they became pregnant. Under ordinary conditions the food of the prospective mother provides not only for her own wants but also for those of the embryo. Between the two organisms there exists a relation which resembles that existing between a house in course of construction and the contractor who supplies the building material. The mother furnishes what is needed to construct the "living edifice," as Huxley called the growing embryo, but she is not responsible for the lines of the building. The embryo is both architect and mechanic, designing the structure and arranging the "organic bricks" in their proper places. The work of construction necessitates the expenditure of an appreciable amount of energy and the creation of waste products that must be removed, lest they accumulate and interfere with the growing structure. These waste products leave the embryo by way of the umbilical cord and the placenta and return thus into the mother's circulation; ultimately they leave the mother through the same channels that carry off her own waste. First and last, then, the nutrition of the mother and of the child are so bound together that it has been impossible to study them separately. Our knowledge of food requirements during pregnancy has been obtained by measuring the food requirements of the mother alone; and as nutrition during gestation is fundamentally the same as nutrition at other times, it is necessary for us first to consider in general the food needed by the human body.
THE FOOD-STUFFS.—The waste products we throw off indicate that the substances which compose our bodies are being constantly broken down and reduced to a condition such that they are useless to us. In normal persons hunger signifies that they need material to replace what has been used up. The substances thus required, if the wants of the body are to be satisfied correctly, are called the food-stuffs; and they are the same during pregnancy as at other times. The foodstuffs are usually classified according to their chemical properties; on this basis they are placed in five groups: (1) Water, (2) Mineral Materials, (3) Proteins, (4) Carbohydrates, (5) Fats.
In view of the different purposes which the foodstuffs serve, it is convenient to group them in another way. Thus, the carbohydrates and the fats may be placed together because they are the body fuel; their value consists in the heat and energy which they yield when acted upon in the tissues. Water and mineral matter, on the other hand, are never a source of energy; they assist in building new tissue or in repairing tissue that already exists. The proteins are unique, in that they may serve either purpose. Primarily the proteins are tissue-builders, but in the absence of sufficient fat or carbohydrate the body burns protein to secure heat and energy.
Each food-stuff, therefore, serves a distinct purpose, and some of them render services which the others cannot perform. A man will die if either water or mineral matter or protein is completely withdrawn from his diet. Fat or carbohydrate, on the other hand, or even both of them, may be excluded for some time without causing serious inconvenience. It is true, nevertheless, that each food-stuff performs some task better than any of the others can perform it, and for that reason all of them should be included in the diet of an healthy individual.
Some of the food-stuffs, such as water and table salt, come to the body separate from the others; but generally the different types reach us intimately mingled in the various articles of food in common use. Foods vary greatly, however, in the amount of the different food-stuffs they contain. The meats, for example, have a relatively large protein content; in the vegetables starch, which is one of the carbohydrates, predominates. As to the choice of food and the amount that is necessary for the average person, generally the appetite is a safe guide; but the accurate observations of physiologists have gone so far as to determine the exact requirements of the body. Not the least important principle taught by these investigations is to avoid dietary fads, for in arranging a satisfactory diet the problem to be solved is not, What is it possible to live on? but, What serves best as nourishment? The experience of countless generations has taught us that we thrive best on a diet which includes all five food-stuffs.
Water constitutes nearly two-thirds of the weight of the body. As water is constantly being given up in the life process, health demands an abundant supply of liquids to replace the waste. The average daily loss has been found to be between two and three quarts. Of this amount the urine constitutes nearly two-thirds; and the remaining third is eliminated through the skin, the lungs, and the bowels. Although the deficiency thus created is met in part by the water in our solid food, the greater part of the loss is made up by the liquids we drink, and we are warned, in a measure, by the sensation of thirst that they are needed.
Mineral material is of the greatest importance as a constituent of our food. It contributes to the welfare of the body in at least three ways; (1) it gives rigidity to the bones, (2) it supplies an essential ingredient of the living substance in all the tissues, (3) it is present in the blood and in the other body fluids, where it is of service in such vital processes as the beating of the heart, the transportation of oxygen to every portion of the body, and the maintenance of an acid or alkaline condition of the digestive juices according as the one or the other is necessary for the assimilation of the food.
An animal deprived of mineral food will die as surely as one deprived of water. In arranging our diets, however, we are not compelled to take the minerals into account, for, with the exception of table salt (sodium chlorid), the meat and vegetables that we eat provide the mineral material the body requires. Iron, for example, which imparts to the blood one of its most essential qualities, occurs in relatively large amounts in apples, spinach, lettuce, potatoes, peas, carrots, and meats. Only now and then does it become advisable to add iron deliberately to the diet. Similarly lime (calcium) the material that makes the bones hard, is present in quantities ample for the needs of the body in the bread, milk, eggs and vegetables that we eat. The remaining mineral constituents of the body, among which the most conspicuous are magnesium, potassium, sulphur, and phosphorus, occur in foods which we are naturally inclined to take, so that we secure an abundance of them unconsciously.
Protein, the third food-stuff which we must eat to keep alive, contains the chemical element nitrogen in such form that it can be incorporated in our tissues. Although most persons derive their protein in part from meat, milk, and eggs, it is possible to satisfy the requirements of the body on a purely vegetarian diet. Experience has shown, however, that it is both natural and advantageous that we employ a mixed diet.
The property of protein to build living tissue and replace tissue waste probably depends upon several factors; but certainly one of them is the presence of nitrogen. So intimately associated are the consumption of the tissue substance and the elimination of nitrogen that we have no better way of judging the amount of tissue substance used in the body than by determining the quantity of nitrogen that appears in its various waste products. From such investigations it has been found that the quantity of protein required to repair the breaking down of the tissues is not great. The average man consumes approximately a quarter of a pound (100 to 120 grams) of protein daily; but this quantity is in excess of his real needs. Indeed, Chittenden has shown that for various classes of individuals, namely, students, athletes and soldiers, half as much is sufficient. Other physiologists, though admitting that this is true, contend that it is inadvisable to regulate one's diet on such a slender basis. Very good reasons are assigned for the view that more protein is needed than just enough to counterbalance the tissue waste. Thus, in the case of animals, it has been found that a diet low in protein finally causes digestive disturbances and other ailments.
Although it does not seem advisable to practise rigid economy in arranging the protein content of the diet, it is equally important that we should not go to the other extreme. The consumption of over- large quantities of protein, as would be the case if we lived exclusively upon meat, increases putrefaction in the intestines and throws unnecessary work upon the kidneys, which are the organs chiefly concerned in getting rid of the waste products of protein.
Carbohydrate is the name given the group of foodstuffs to which the sugars belong. The food value of cane sugar, the most familiar member of the group, was recognized even in prehistoric days by the natives of India. By boiling the plant we call sugar-cane they obtained a substance to which they gave the name Sakkara, and from this our word sugar evidently originated. The roots of this plant were carried into Europe and cultivated during the Middle Ages. Obviously, its value was and is appreciated, since the cultivation of the sugar-cane and the sugar-beet has become the foundation of a great modern industry.
There are some persons, perhaps, who do not realize that beside cane sugar many kinds of carbohydrate occur in our food. Glucose or grape sugar, for example, occurs not only in the fruit indicated by its name, but also in other fruits, in corn, in onions, and in the common vegetables. Glucose is especially suited to act as nourishing food. In keeping with that fact our digestive juices convert most of the sugars we eat, if not all of them, into glucose, which is regularly present in our blood. It is unnecessary to enumerate all or even the more important compounds included in the carbohydrate group; but everyone should know that starch is its chief member, and that after being thoroughly digested starch enters the body as glucose and therefore serves the same purpose as sugar.
The value of carbohydrates as a source of heat and energy may be accurately measured, and is technically expressed in terms of a unit, called the calorie. As the energy which our bodies require may be estimated in the same terms, it is possible to determine whether or not our food is equal to our wants. Very naturally the energy requirements of any individual are influenced by his weight and by the work he does. But we may take as a standard the results of an extensive study of American families which indicate that women require four-fifths as much energy-yielding food as men. It also seems safe to conclude that a woman weighing 130 pounds who does her own housework requires food every day having an energy-value of 2,500 calories; smaller women and those who do no work require somewhat less. In a mixed diet the chief source of this energy—and the source from which it is most economically obtained—is the carbohydrates.
Fat yields more energy and heat than does carbohydrate, bulk for bulk; but fat is burned by our tissues less readily. We instinctively avoid eating a great deal of this food-stuff; in the course of a day the average person consumes no more than one or two ounces. The natural aversion which many feel toward fat may possibly depend upon the difficulty with which they assimilate it. In colder climates, however, we know fat to be a staple article of diet; and it is not unlikely that the very conditions which make it necessary there explain the unusual tolerance for it.
Fat is more than fuel. Deposited in our bodies, beneath the skin for example, it prevents the escape of heat that we generate and protects us against the penetration of cold. This food-stuff, therefore, contributes in several ways toward maintaining the temperature of the body at a constant level.
Our source of fat is chiefly animal food and in a smaller measure vegetables; but the fat our food contains is not altogether responsible for the fat in our bodies. Carbohydrates, if in excess of momentary needs, are partly converted into fat and stored as such. A reserve supply of nourishment is thus provided, and is drawn upon only when the food that we consume does not contain as much energy as we expend.
WHAT WE DO TO OUR FOOD.—With the exception of water and mineral substances, the food-stuffs must undergo chemical alterations before they are capable of being absorbed into the body; this is the work of digestion. The digestive processes, the main purpose of which is to break up the carbohydrates, proteins, and fats into substances of much simpler chemical structure, begin in the mouth and are not completed until some time after the food has entered the intestine. As the food moves through the alimentary canal, it is mixed with the various digestive juices containing ferments, such as pepsin, which are the active agents of digestion. Although digestive processes go on automatically, they are, in a degree that is far from negligible, influenced by the mind. Thus, cheerfulness promotes digestion, and not infrequently mental depression may be the direct cause of indigestion. Indeed, it is chiefly in regard to the state of the mind of the prospective mother that the existence of pregnancy may be said to have a bearing, whether favorable or unfavorable, upon her digestion.
The digestive juices are prepared in glands which lie either within the lining of the alimentary canal or adjacent to it. In the latter event the glands are connected with the canal by means of tubes. These glands must be warned when to pour out their secretion, and their very first warning usually comes from the agreeable sensations experienced when we see, smell, or taste inviting food. If we are hungry, our viands attractive, and our surroundings congenial, the stimulus excites a plentiful secretion of the digestive juices; conversely, the opposite conditions, to some extent, check their flow.
The sight of attractive food, as we all know, "makes the mouth water," that is, it calls forth the saliva which contains one of the digestive ferments. Thus, at the beginning of a meal, favorable conditions for digestion are established. The saliva, however, acts only upon starch; and, moreover, its action upon this carbohydrate is weak unless the food is thoroughly chewed and mixed in the mouth. Most of us, perhaps, overlook the importance of mastication, which not only crushes all the food-stuffs, preparing them for efficient digestion, but also stimulates the flow of the digestive juices. Furthermore, by thoroughly masticating our food, we know intuitively when we have had enough, and thus avoid overeating.
In the stomach the digestion of starch is continued for a time, but the chief work of gastric digestion concerns the proteins. They alone are attacked by pepsin, a ferment secreted by the mucous membrane of the stomach. Moreover, since pepsin is able to act only when an acid is present, the gastric mucous membrane also secretes hydrochloric acid.
Just as the digestive glands in the neighborhood of the mouth become more active when we are conscious that desirable food is at hand, so do the glands in the stomach. Mastication also stimulates the flow of the gastric juice, and this flow is greater if we enjoy what we eat. Furthermore, it has been shown that, after entrance into the stomach, the food itself increases the flow of the digestive juices. All articles of food are not, however, equally efficient in producing this effect: thus meat requires more pepsin for satisfactory digestion than bread, and consequently meat calls forth a larger quantity of gastric juice.
Fat in all probability is not digested in the stomach; even starch and protein are not broken down sufficiently by the time gastric digestion is complete to permit them to be absorbed into the body. "The value of digestion in the stomach," as Howell says, "is not so much in its own action as in its combined action with that which takes place in the intestine." It is even possible for satisfactory digestion to take place without the assistance of the stomach. This fact has been substantiated by several cases in which men have lived for years after the stomach was removed to eradicate a disease. It is true, nevertheless, that intestinal digestion can be performed more economically if it begins where gastric digestion normally leaves off.
Of the changes wrought in the food by the various digestive processes, those which are the most profound take place in the intestine. While the food is being moved through this organ—some thirty feet in length—it is reduced to simple chemical fragments, which are absorbed by the intestinal wall. Digestion in the intestine is carried on through the agency of a number of ferments, the more important of which are supplied in the juice manufactured by the pancreas. The pancreatic secretion contains three separate and distinct ferments, which act respectively upon carbohydrate, protein, and fat. The absorption of fat, however, is materially assisted also by the action of the bile.
A part of what we eat always escapes digestion; the unused portion, it has been estimated, is somewhat less than one-tenth of an ordinary mixed diet. The residue from vegetables is notably larger than the residue from meat. The undigested portions of all the food- stuffs collect in the lowermost portion of the intestine and form a part of the feces. Here also are gathered the indigestible material we have eaten, the products of bacterial decomposition in the intestine, and other waste substances that the body should throw off.
HOW MUCH FOOD IS NEEDED DURING PREGNANCY?—In connection with the development of the child we have already referred to the difference in the purpose of the constructive processes which go on in the earlier months of gestation and those which take place in the later months. In a general way the first half of pregnancy is occupied with the formation of the embryo from relatively simple structural elements, the second half with its growth into an infant, which acquires ninety per cent. of its substance and weight at birth after the fifth month of embryonic development. A similar contrast may be observed in the nutritional processes of the mother. Often, at the beginning of pregnancy, the appetite is poor and there is indisposition of one kind or another, with the natural result that there is slight if any change in the mother's weight; whereas later a period ensues when her appetite increases, her health improves, and she gains in weight.
Since it is natural that the weight of the mother should remain practically stationary during the early months of pregnancy, it is clear that a diet which has previously been ample will likewise be sufficient for some time after conception has taken place. To most persons, however, it is not clear that the quantity of food ordinarily eaten will suffice also during the later months of pregnancy. On the contrary, popular opinion holds that the prospective mother "should eat for two." It is not unimportant to point out the erroneous character of this superstition, because overeating during pregnancy is much more likely to provoke discomfort than insufficient nourishment.
In order to comprehend the nutritional needs of the prospective mother, one must keep in mind the fact that our food always serves two purposes. These are, as we have seen, to build or to repair tissue and to furnish heat and energy. Since these needs of the body during pregnancy—as at all other times—are best understood when considered in their relation to the food-stuffs which supply them, we shall take up these various ingredients separately.
Protein, which repairs tissue and also furnishes the substance from which new tissue is made, is used more economically during pregnancy than when the maternal functions are inactive. As a result of this economy the same allowance of protein which is sufficient before conception is sufficient also during pregnancy. This fact has been put in the clearest light by extensive observations made upon animals. Dogs which were not pregnant, for example, have been carefully fed so that their food should contain just enough protein to cover the needs of the body and keep their weight constant. Subsequently, when these animals became pregnant precisely the same amount of protein was fed to them. The result was that they gained in weight, and at the same time the waste products of protein they threw off were notably diminished. Such observations, of which there have been a large number yielding concordant results, may be safely taken to mean that an amount of protein previously satisfactory for the animal is also sufficient for her during pregnancy. We are forced to conclude that protein was used more sparingly in the latter condition—a view which has been repeatedly confirmed with regard to human beings as well as animals. It is found, for example, that an amount of protein competent to meet the needs of a man of a given weight will not only provide for the wants of a woman of equal weight while she is pregnant, but will also leave a surplus sufficient for the growth of the fetus.
With regard to the mineral substances, likewise investigations indicate that the "housekeeping" of the body during pregnancy proceeds along unusually economic lines. It is not advisable, therefore, to make any change in the diet with regard to these substances. Attempts have been made to cut down the amount of minerals in the food for the purpose of softening the fetal skeleton. The success sometimes attributed to these efforts is, however, very doubtful, for we know that the mother's tissues will be robbed of minerals for the embryo whenever her food fails to contain them in sufficient amount for her own needs and those of the child. Practically speaking, the mineral content of diet during pregnancy requires no thought, for so long as meat and vegetables are eaten in satisfactory quantity the mineral nutrition will take care of itself.
The food-stuffs which supply heat and energy, since the amount of energy utilized by the body during the latter months of pregnancy is somewhat in excess of that previously required, do not follow the same rule as the protein and the mineral matter. It has been found that just before the fetus becomes mature the energy requirements of the mother are approximately one-fifth greater than in the non- pregnant condition. It is certain, however, that no extra demand for energy exists until the fifth or sixth month of pregnancy, and that the excessive requirement is extremely small until the last three or four weeks. Even then the prospective mother requires less energy- giving food than the average man.
Since the body handles carbohydrate more readily than fat, it is preferable that whatever additional energy pregnancy necessitates should be supplied by carbohydrates. An increase in the daily consumption of fatty food, over and above that previously found agreeable, is not only unnecessary but undesirable. Every-day experience teaches that less fat taken with the meals promotes the comfort of the prospective mother. A glass of rich milk a little before meal time, however, not only makes up for this omission but also prevents "heart-burn," a very common ailment of pregnancy.
Although there is an appreciable increase in the quantity of starch and sugar utilized toward the end of pregnancy, it is generally quite unnecessary to increase these materials correspondingly in the diet. Nearly everyone eats more of all the food-stuffs than the body needs. In the case of the prospective mother the surplus ordinarily taken meets every need incident to her additional energy requirements. Because we eat more than we need, someone has said, with as much truth as humor, that prospective mothers "neither want nor need to eat for two. The fact is more likely that enough for one is too much for two." For the average woman it is wiser to take less during pregnancy rather than more, for over-indulgence is apt to lead to indigestion. The moment when the appetite is satisfied should be accepted as the stopping point, and that will be instinctively recognized if one eats deliberately, and thoroughly masticates the food.
Regularity in the hour of eating is always healthful, and for some prospective mothers three meals a day prove quite satisfactory. Not a few, however, who adhere to this habit make the mistake of eating more than is wise; and large meals are particularly inappropriate to pregnancy. On this account most prospective mothers will be more comfortable if they take some simple and wholesome nourishment at fixed times between meals. Such an arrangement modifies a ravenous appetite, and it is, at the same time, beneficial to those who are not inclined to eat enough at the regular meals. If small amounts of food are taken five or six times a day, a tendency to be nauseated, which is not uncommon in the early months of pregnancy, can often be averted. In the latter months, too, because the capacity of the stomach is diminished through the encroachment of the enlarged womb, frequent meals generally contribute toward comfort and health. While the inevitable consequences of overloading the stomach are to be avoided at all times of the day, it is especially important to remember the disagreeable results of a hearty meal at night. The evening meal should be a light one and should be eaten three or four hours before going to bed.
THE IMPORTANCE OF LIQUID NOURISHMENT.—Every prospective mother should have brought to her attention the great importance of drinking water at regular times and in larger quantities than was formerly her custom. Since water constitutes two-thirds of the substance of our bodies, it is necessary, of course, for everyone; but during pregnancy it is especially necessary for the building of new tissue and for safeguarding the mother's kidneys. Prospective mothers would protect themselves against a number of ailments if they were more careful to drink a sufficient amount of liquids. They may easily determine whether they are doing so, for whenever the urine passed during twenty-four hours measures less than a quart, they are not drinking enough. Generally the daily elimination of urine fluctuates between two and three pints; a larger amount, however, is rather a favorable indication than the reverse.
The variations in the quantity of liquids that healthy persons drink make it impossible to say just how much anyone should take. It may be said with confidence, however, that women who are pregnant should consume at least three quarts of fluid every day, and by far the greater portion of this should be water. The rest may be taken in the form of milk, soup, cocoa, and chocolate. Against the moderate use of tea and coffee no valid objection can be raised; the tradition that they may cause miscarriage is incorrect. For well-known reasons the habitual use of strong tea or coffee is always harmful, and it is, therefore, equally as objectionable during pregnancy as at other times. Beverages which contain a small percentage of alcohol, such as malt and beer, may or may not be helpful; they should be regarded as medicine, not to be taken without consulting a physician.
THE CHOICE OF FOOD.—There is no diet specifically adapted to the state of pregnancy; the prospective mother may usually exercise the same freedom as anyone else in the selection of food. She should, however, choose what will agree with her and avoid that which she cannot digest and assimilate. Personal experience in the main must guide everyone as to what to eat, and most women may follow the dictates of appetite after they become pregnant as safely as they did before.
It is true, of course, that careful scientific observations have taught not only what the nutritional requirements of the body are, but also how the diet may be arranged to satisfy these requirements most conscientiously and economically. "Caloric Feeding" is the name given the method which aims to furnish an individual the exact amount of food, and usually to furnish it at a minimum cost. Its principles are of great practical importance to the commissary of an army or to the purveyor of an institution which provides for large numbers of people; but it is neither necessary nor advisable that the diet of any healthy individual be regulated solely with a view to satisfying the actual requirements of his or her body. Food should possess other qualities than fuel value: first of all it must be appetizing, for appetizing food receives the most thorough digestion.
We all know how variable are our appetites. What appeals to one will not appeal to another, and frequently the same person has no appetite to-day for food that she will eat with relish to-morrow. Precise rules, therefore, to guide healthy persons in the selection of their food are not obtainable; neither are they desirable, for the exercise of individual preference possesses notable advantages. In order, however, that there may not also be disadvantages, the prospective mother, like anyone else, must be content to choose food that is simple, wholesome, and of such a character that it will not throw an undue burden upon the digestive organs.
During pregnancy some uncooked food should be eaten every day. Ripe fruit answers the purpose admirably. At all seasons of the year fruit of one variety or another, such as apples, peaches, apricots, pears, oranges, figs, cherries, pineapples, grapes, plums, strawberries, raspberries, and blackberries may be obtained and should have a place in the diet. In making a choice personal taste alone need be consulted.
Fruit contains a large proportion of water as compared with other articles of diet; and, therefore, is especially capable of quenching thirst. Fruit also lessens the desire for sweets, acts as a laxative, and furnishes mineral material which the body needs. Its laxative effect is most pronounced when it is eaten alone, as, for example, in the morning before breakfast or at night upon going to bed; cooked fruit taken with the meals acts much less effectively. Fruit and vegetable salads are wholesome, but cannot be recommended indiscriminately during pregnancy, for not infrequently the dressing used with them causes discomfort. Under these circumstances it is obvious that one should do without salads.
The cereals wheat, corn, rye, oats, and barley are the most prominent source of starch in an ordinary diet. Breakfast foods manufactured from grain are not only nutritious in themselves, but their value is increased by the milk or cream used with them. Bread is the staple starch-containing food in this country, and starch is our main source of energy, but it is necessary to eat only a small quantity of bread, if the diet includes a relatively large amount of vegetables. It is advantageous to use bread made from unbolted flour (Graham bread) or from corn meal, because the coarse undigested residue which they leave stimulates the movements of the intestine and assists in overcoming the constipation which is generally associated with pregnancy. Pastry must be avoided by those who suffer from indigestion; and every prospective mother should eat pastry only occasionally, and not very much of it at any time. The best desserts are raw and freshly cooked fruit, preserves, gelatin, custard, ice cream, and light puddings, such as rice and tapioca.
Vegetables should be abundant in the diet of every prospective mother. Some of them, however, are digested with difficulty, and on this account cabbage, cauliflower, corn, egg-plant, cucumbers, and radishes should be eaten sparingly. Occasionally it will be necessary to exclude them from the diet altogether. Other vegetables produce flatulence, and for that reason parsnips and beans may cause discomfort. The prejudice, however, which exists against onions, asparagus, and celery should not be heeded; all of them are harmless, and celery thoroughly cooked with milk is very wholesome. Besides these, moreover, there are many highly nutritious and easily digestible vegetables which can be freely recommended, such as both sweet and white potatoes, rice, peas, lima beans, tomatoes, beets, carrots, string beans, spinach, Brussels sprouts, and lettuce.
Vegetable food contains all the material necessary to sustain life, and some persons prefer to adhere strictly to a vegetarian diet. Most prospective mothers, however, find a mixed diet more agreeable, and this is sufficient reason for using it. Furthermore, no fair objection can be raised against the use of animal food, provided the pregnancy is normal. It is important, nevertheless, to remember that meat contains protein in concentrated amounts, and that meat once a day answers every need not only of the mother but also of the growing fetus.
The ideal animal foods are milk and eggs; they contain every ingredient necessary to repair old and to form new tissues. But usually the prospective mother may have any animal food she wishes: beef, veal, lamb, poultry, game, fish, oysters, and clams. The relatively large fat-content of pork, goose, and duck renders them indigestible for some persons, who, of course, should not eat them.
From what we have learned about foods in general and their relation to pregnancy it is clear that the question so often asked by prospective mothers, "Are there any special directions regarding my diet?" may be briefly answered as follows: Under no circumstances is the need of food increased in the first half of pregnancy. During the last two or three months, while the most notable growth of the fetus is in progress, there is a perceptible increase in the amount of energy expended by the mother, and this may be readily supplied by a glass of milk or some equally simple nourishment between meals. Furthermore, throughout pregnancy, most women are made most comfortable by frequent small meals; they will almost certainly suffer discomfort if heavy meals are eaten three times a day.
The most nearly ideal diet consists of very little meat and a comparatively rich allowance of vegetables and fruit. The food should be chosen with regard to individual appetite and should be varied frequently. Thorough mastication always increases the efficiency of a diet. Thus the food will be most perfectly mixed with saliva and broken into fragments which can be readily attacked by the digestive juices of the stomach and the intestines.
CRAVINGS.—There is a well-known tradition that women who are pregnant are subject to longings for one article of diet or another, and that unless the desire be promptly gratified the child will be "marked." In the light of what has already been said regarding maternal impressions, this evidently is nonsense. A prospective mother, like anyone else, does frequently desire one article of food more than another. So long as the object of her wish is not obviously harmful, it should be granted; but if it is not granted no harm will come to the child.
Remarkable instances in which disgusting substances have been craved and eaten are often talked about and have even found their way into popular novels. The unfortunate victims of these unnatural cravings are not of sound mind. With reference to them a physician of unusually broad experience wrote fifty years ago, "I have never met with any example of this sort; which leads me to infer that these longings are more frequent in books than in the practice of our art." This conclusion is even more fully justified to-day than when originally expressed.
THE RELATION BETWEEN THE MOTHER'S DIET AND THE SIZE OF THE CHILD.— With the beginning of careful, scientific study of the nutritional problems of pregnancy, investigators were interested to learn the source of the material which was used to build up the child's body. Two possibilities suggested themselves: one that the material came from the mother's food and the other that it was derived from her own flesh. In order to determine which of these methods was the natural one, animal experimentation was resorted to and gave identical results in the hands of independent observers. It was found, as I have already stated, that the same diet which had previously kept an animal's weight constant was sufficient to meet her requirements during pregnancy and also to provide for the growth of her offspring. The mother animal was actually found somewhat heavier at the termination of pregnancy than at the beginning. It seemed fair to conclude, therefore, that nutrition had proceeded along more economic lines, and that under these conditions the customary diet had furnished the material for the formation of the young. Still other observations indicated that, if the food is not sufficient for both mother and offspring, it is Nature's plan to protect the young and leave the mother's wants incompletely satisfied. On the other hand, when an unnecessarily large amount of nourishment is taken, the excess is stored partly in the young, and partly in the mother's body.
There can be no doubt that the results of such observations upon animals are applicable to human beings. Everyone familiar with the practice of obstetrics knows that women who gratify enormous appetites during pregnancy, especially if they also fail to take exercise, give birth to large children. On the other hand, it is said that children born during times of famine are frequently delivered prematurely, or, if mature, they are small and puny. A similar though much less marked contrast exists between the babies of the working classes and the well-to-do, and clearly indicates that the weight of the baby varies directly with the food of the mother.
The quantity of the food is more influential than its quality, though the latter is also a factor in determining the size of the child. An excessive amount of starch or sugar in the mother's diet is stored as fat in the child. On this account it is reasonable to eat sparingly of candy, cake, and other sweets; but further attempts to reduce the weight of the fetus by discrimination against different articles of food are not advisable.
The various theories that have been advanced with a view to reducing the size of the child are impracticable; some of them, rigidly carried out, would actually jeopardize the health of both beings. All of them are designed to make the infant's bones soft and to diminish the fat in its body. To this end, generally about two months before the expected date of birth, the mother's diet is arranged to consist chiefly of meat; and as far as possible she is denied candy, sweet desserts, soup, bread, cereals, vegetables, and water. Such a diet overlooks, among other things, the tremendous importance of liquids to the woman who is pregnant. Certainly its indiscriminate use would result in far more harm than good; and no one should adopt it without minute directions from a physician.
Attempts to make the infant's bones soft by limiting the mother to food containing extremely small amounts of lime and other minerals are also unnatural, for we have learned that whenever the mother's food fails to contain the material the fetus requires the mother's tissues are called upon to supply it. Under these conditions, therefore, her bones will give up their lime.
It is of the very first importance that the mother's nourishment be correct from the standpoint of her own requirements, and such treatment will also redound most beneficially to the child. She should never fall, however, into the error of over-eating, which will not benefit her and will cause unnecessary growth of the fetus. On the other hand, there can be no justification for measures that tend to weaken her. She may be careful, in other words, to avoid over- growth of the fetus, but should not adopt a diet so restricted as to interfere with normal development. So long as her health is successfully maintained, she may give herself no concern as to what the size of the child is likely to be. That is a detail which concerns her physician, and which will be observed by him several weeks before the expected date of birth.