Chapter 2 FOOD

Section I-Quantity of Food

The body has often been compared to a blacksmith's forge, the lungs being the bellows and food the coal. The comparison is a good one, for food is actually burned in the body by the aid of the air we breathe.

Calories

All food is capable of being used as body-fuel and by far the greater part of it is so used. Consequently, food is measured in fuel-units, called calories. Many people eat too much, that is, too many calories; some eat too little, that is, too few calories. In both cases the person is usually unaware of the fact, because he makes the mistake of measuring his food by its weight or bulk. Some foods are concentrated, that is, contain many calories of food value in a given bulk; others are bulky, that is, contain few calories in a given bulk. For instance, olive oil is concentrated, and most vegetables are bulky. A third of an ounce of olive oil contains 100 calories, which is as much as is contained in a pound or more of tomatoes, lettuce, celery, cucumbers, string beans, asparagus, or watermelon.

It will help to give a picture of food values if, before going further, we note how much it takes of some of the common foods to make a given amount of food value, say 100 calories. It is surprising in how many cases the ordinary amount of food served at table happens to contain about 100 calories. We find 100 calories in a small lamb chop (weighing about an ounce); in a large egg (about 2 ounces); in a small side-dish of baked beans (about 3 ounces); in 1? cubic inches of cheese (about an ounce); in an ordinary side-dish of sweet corn (about 3? ounces); in one large-sized potato (if baked, about 3 ounces; if boiled, about 4 ounces); in an ordinary thick slice of bread (about 1? ounces); in one shredded wheat biscuit (about an ounce); in a very large dish of oatmeal (about 6 ounces); in a small piece of sponge-cake (about an ounce); in a third of an ordinary piece of pie (about 1? ounces); in three teaspoonfuls or 1? lumps of sugar (about 1 ounce); in a dozen peanuts (about ? of an ounce); in eight pecans (about ? an ounce); in four prunes (about 1 ounce); in two apples (about 7 ounces); in a large banana (about 4 ounces) in half a cantaloup (about 9 ounces); in seven olives (about 1? ounces); in a very large orange (about 10 ounces); in an ordinary pat of butter (about ? an ounce); in a quarter of a glass of cream (about 2 ounces); in a small glass of milk (about 5 ounces). (See Supplementary Notes for "Table of Food Values.")

The ordinary sedentary man needs about 2,500 calories per day. But the larger the person (provided the bulk is due to muscle and active tissue and not to fat) or the more muscular the work he does, the more food he needs. It has been found that the number and activity of cells forming the organs and muscles and blood affect the food requirement.

Favorable Weight

Life insurance experience has clearly shown that weight, especially in relation to age, is an important factor in influencing longevity.

Except in the earlier ages of life, overweight (reckoned relatively to the average for that age) is a more unfavorable condition, in its influence on longevity, than underweight.

The question of whether an individual is really underweight or overweight can not be determined solely by the life insurance tables. (See Supplementary Notes, "Influence of Build on Longevity.") Some types who are of average weight according to the table, may be either underweight or overweight when considered with regard to their framework and general physical structure. Nevertheless, it should be remembered that notwithstanding the effort of life insurance companies to carefully select the favorable types of overweight and underweight, the mortality experience on youthful underweights has been unfavorable, and the mortality experience on middle aged and elderly overweights has been decidedly unfavorable. The lowest mortality is found among those who average, as a group, a few pounds over the average weight before age 35, and a few pounds under the average weight after age 35. That is, after the age of 35, overweight is associated with an increasingly high death rate, and at middle life it becomes a real menace to health, either by reason of its mere presence as a physical handicap or because of the faulty living habits that are often responsible for its development.

Overweight

If there is a family tendency to overweight, one should begin early to form habits that will check this tendency. If considerable overweight is already present, caution is necessary in bringing about a reduction. Barring actual disease, this can usually be done without drugs if the person will be persevering and faithful to a certain regime.

Constant vigilance is necessary, yet it is worth while when one considers the inconvenience as well as the menace of obesity.

After the age of 35, 15 to 20 pounds over the average weight should prompt one to take careful measures for reducing weight. Habits should be formed that will keep the weight down automatically, instead of relying upon intermittent attempts that are more than likely to fail. No matter how well one feels, one should take steps to keep out of the class that life insurance companies have found to be undesirable as risks.

Accessories

One reason why many people eat great quantities of food without realizing it, is the common delusion that many articles such as candy, fruits, nuts, peanuts, popcorn, often eaten between meals, "do not count." Another common oversight is to overlook accessories, such as butter and cream, which may contain more actual food value than all the rest of a meal put together. Ice-cream and other desserts also have more food value than is usually realized. Nature counts every calory very carefully. If the number of calories taken in exceeds the number used by the body (or excreted unused), the excess accumulates in fat or tissue. Thus, if some 3,000 calories are taken in each day and the calories used up or excreted are only 2,800, then 200 must be retained and accumulated in the body.

Underweight

A person who is not heavy enough can usually gain weight by following the general rules of hygiene, especially in the matter of increasing the fuel or energy foods. But he should not force himself to eat beyond his natural capacity to digest and assimilate the food, while overfatigue and exhausting physical exertion should be carefully avoided.

Diet in Middle Life

As age advances, the consumption of meat and all flesh foods should be decreased and that of fruit and vegetables, especially those of bulky character and low food value, such as lettuce, tomatoes, carrots, turnips, salsify, oyster-plant, watercress, celery, parsnips, should be increased.

Diet in Hot Weather

Generally the quantity of food should be slightly decreased in hot weather, when fewer calories are needed to sustain the heat of the body. In particular, less meat should be eaten in the summer, on account of what is called the "specific dynamic action of protein," that is, the special tendency of meats and like foods to produce immediate heat.

Each individual must decide for himself what is the right amount of food to eat. In general, that amount is right which will maintain the most favorable condition of weight. If the weight, endurance, and general feeling of well-being are maintained, one may assume that sufficient food is taken.

Brainwork and Eating

It is physical, not mental work, which uses up the greater part of our food. The common impression that brain-work or expenditure of mental energy creates a special need for food is erroneous. The sedentary brain-worker often gains weight without eating very much. What he really needs is exercise, to use up the food, but if he will not take exercise, then he should reduce his food even below the small amount on which he gains weight.

Eating When Fatigued

Which meal in the day should be heavy and which light depends largely on one's daily program of work, the aim being to avoid heavy meals just before heavy work. When very tired it is sometimes advisable to skip a meal or to eat only lightly, as of fruits and salads. A man who eats heartily when he is very tired is likely to be troubled afterward with indigestion.

(See Supplementary Notes for specific directions regarding diet for underweight and overweight.)

Section II-Protein Foods

Protein, Fat, and Carbohydrate

In the last section it was stated that food is fuel. But there is one constituent of food which, while it can be used as fuel, is especially fitted for an entirely different purpose, namely, to build tissue, that is, to serve for the growth and repair of the body. This tissue-building constituent in food is called protein. The two other chief constituents in food are fat and carbohydrate, the last term embracing what are familiarly known as starch and sugar. Fats and carbohydrates are only for fuel and contain carbon as the essential element. Protein contains nitrogen as the essential element in tissue-building. The white of egg and the lean of meat afford the most familiar examples of protein. They consist entirely of protein and water. But meat and eggs are not the only foods high in protein. In fact, most ordinary foods contain more or less protein. The chief exceptions are butter, oleomargarine, oil, lard, and cream-which consist of fat (and water)-and sugar, sirups, and starch, which consist of carbohydrate (and water).

Proportion of Protein

Foods should be so selected as to give to the ration the right amount of protein, or repair-foods, on the one hand, and of fats and carbohydrates, or fuel-foods, on the other. A certain amount of protein is absolutely essential. While, for a few days, protein may be reduced to little or nothing without harm, if the body be long deprived of the needed protein it will waste away and ultimately death will result. Therefore, too little protein would be a worse mistake than too much.

The right proportion of protein has been the subject of much controversy. According to what are regarded as the best investigations, it is generally about 10 per cent. of the total number of heat-units consumed. This does not, of course, mean 10 per cent. of the total weight nor 10 per cent. of the total bulk, but 10 per cent. of the total nutriment, that is, 10 calories of protein out of every 100 calories of food.

Human Milk

Most persons in America eat much more protein than this. But that 10 calories out of 100 is not too small an allowance is evidenced by the analysis of human milk. The growing infant needs the maximum proportion of protein. In the dietary of the domestic animals, the infant's food, the mother's milk, is richer in protein than the food of the grown animal. Consequently an analysis of human mother's milk affords a clue to the maximum protein suitable for human beings. Of this milk 7 calories out of every 100 calories are protein. If all protein were as thoroughly utilized as milk-protein or meat-protein, 7 calories out of 100 would be ample, but all vegetable proteins are not so completely available. Making proper allowance for this fact, we reach the conclusion that 10 calories out of every 100 are sufficient.

Excessive Use of High-Protein Foods

A chief and common error of diet consists, then, in using too much protein. Instead of 10 calories out of every 100, many people in America use something like 20 to 30. That is, they use more than double what is known to be ample. This excessive proportion of protein is usually due to the extensive use of meat and eggs, although precisely the same dietetic error is sometimes committed by the excessive use of other high-protein foods such as fish, shell-fish, fowl, cheese, peas and beans, or even, in exceptional cases, by the use of foods less high in protein when combined with the absence of any foods very low in protein. The idea of reducing the protein in our diet is still new to most people.

Injuries From Over-abundance of Protein

Prof. Rubner of Berlin, one of the world's foremost students of hygiene, said, in a paper on "The Nutrition of the People," read before the recent International Congress on Hygiene and Demography:

"It is a fact that the diet of the well-to-do is not in itself physiologically justified; it is not even healthful. For, on account of false notions of the strengthening effect of meat, too much meat is used by young and old, and by children, and this is harmful. But this meat is publicly sanctioned; it is found in all hotels; it has become international and has supplanted, almost everywhere, the characteristic local culinary art. It has also been adopted in countries where the European culinary art was unknown. Long ago the medical profession started an opposition to the exaggerated meat diet, long before the vegetarian propaganda was started. It was maintained that flour foods, vegetables, and fruits should be eaten in place of the overlarge quantities of meat."

When protein is taken in great excess of the body's needs, as is usually the case in the diet of Americans, added work is given the liver and kidneys, and their "factor of safety" may be exceeded.

Animal Proteins

Flesh food-fish, shell-fish, meat, fowl-when used in great abundance, are subject to additional objections. They tend to produce an excess of acids, are very prone to putrefaction, and contain "purins" which lead to the production of uric acid. This is especially true of sweetbreads, liver and kidney. The well-known deficiency in flesh foods of lime often needs to be taken into consideration in the dietary. Some of the vegetable foods, such as peas and beans, rich in protein, are likewise not free from objection. Their protein is not always easily digested and is, therefore, likewise liable to putrefaction. Unlike most vegetable foods, they contain some purins. These foods are, however, rich in iron, which renders them a more valuable source of protein for children and anemic people than meat. Also, an excess of protein is not so likely to be derived from such bulky foods as from meat, which is a concentrated form of protein.

We have spoken thus far only of the needed proportion of protein. The remainder of the diet, say 90 per cent. of the calories, may be divided according to personal preference between fats and carbohydrates in almost any proportion, provided some amount of each is used. A good proportion is 30 per cent. fat and 60 per cent. carbohydrate.

Section III-Hard, Bulky, and Uncooked Foods

The wise choice of foods does not consist entirely in balancing the ration as to protein, fat, and carbohydrate.

Hard Foods

Hard foods, that is, foods that resist the pressure of the teeth, like crusts, toast, hard biscuits or crackers, hard fruits, fibrous vegetables and nuts, are an extremely important feature of a hygienic diet. Hard foods require chewing. This exercises and so preserves the teeth, and insures the flow of saliva and gastric juice. If the food is not only hard, but also dry, it still further invites the flow of saliva. Stale and crusty bread is preferable to soft fresh bread and rolls on which so many people insist. The Igorots of the Philippines have perfect teeth so long as they live on hard, coarse foods. But civilization ruins their teeth when they change to our soft foods.

Bulk Versus Concentrated Foods

Most of the ordinary foods lack bulk; they are too concentrated. For this purpose it is found that we need daily, at the very least, an ounce of cellulose, or "woody fiber." This is contained in largest measure in fibrous fruits and vegetables-lettuce, celery, spinach, asparagus, cabbage, cauliflower, corn, beets, onions, parsnips, squash, pumpkins, tomatoes, cucumbers, berries, etc.

Until recently would-be food reformers have made the mistake of seeking to secure concentrated dietaries, especially for army rations. It was this tendency that caused Kipling to say, "compressed vegetables and meat biscuits may be nourishing, but what Tommy Atkins needs is bulk in his inside."

Raw Foods

Vitamins

Cooking is an important art; but some foods when cooked lose certain small components called vitamins, which are also found in the skin or coating of grains, especially rice, also in yolk of egg, raw milk, fresh fruit, and fresh vegetables, especially peas and beans. These vitamins are very important to the well-being of the body. Their absence is probably responsible for certain diseases, such as beriberi, scurvy, and possibly pellagra, as well as much ill health of a less definite sort. Some raw or uncooked foods, therefore, such as lettuce or tomatoes, celery, fruits, nuts, and milk, should be used in order to supply these minute and as yet not well-understood substances which are destroyed by the prolonged cooking at the temperature which is employed in order to sterilize canned foods. They are also diminished and often destroyed by ordinary cooking, except in acid fruits and acid vegetables.

Raw Milk

It is true that only very clean milk is entirely safe in an absolutely raw state, and that heat is usually needed to kill the germs. But this heat, even at the comparatively low temperature of pasteurization, has been found to destroy the vitamins that prevent scurvy. Orange juice should always be given to infants over one month old who are fed pasteurized milk.

Not all foods can be taken raw with advantage. Most starchy foods, such as cereals and potatoes and unripe fruit must, of course, be cooked in order to be made fit to eat.

Disinfection

Raw foods have dangers of their own in carrying germs and parasites, and it is extremely advisable that all raw foods should be very thoroughly washed before eating.

Acids and Inorganic Salts

In addition to protein, fat, carbohydrate, and vitamins, there are other elements which the body requires to maintain chemical equilibrium, and for the proper maintenance of organic functions. These are the fruit and vegetable acids and inorganic salts, especially lime, phosphorus, and iron. These substances are usually supplied, in ample amounts, in a mixed diet, containing a variety of fruits and vegetables and an adequate amount of milk and cream. Potatoes, feared by some in acid condition (such as gout), are actually valuable because of their alkalinity.

Section IV-Thorough Mastication

Whether it be from lack of hard foods, requiring prolonged chewing, or from the nervous hurry of modern life, or from other causes, it is undoubtedly a fact that most people in America eat too rapidly. The correction of this habit will go far toward reforming an individual's diet in every way.

Thorough mastication means masticating up to the point of involuntary swallowing. It does not mean forcibly holding the food in the mouth, counting the chews, or otherwise making a bore of eating. It merely means giving up the habit of forcing food down, and applies to all foods, even to liquid foods, which should be sipped.

Evils of Insufficient Mastication

The consequences and evils of insufficient mastication are many, and may be enumerated as follows: Insufficient use of the teeth and jaws (and hence dental decay as well as other and worse dental evils); insufficient saliva mixed with the food (and hence imperfect digestion of the starchy substances); insufficient subdivision of food by mastication (and hence slow digestion); the failure of the taste nerves to telegraph ahead, as it were, to the stomach and other digestive organs an intimation of the kind and amount of digestive juices required (and hence indigestion); the overseasoning of food to make it relishable even when bolted (and hence overeating and irritation of the mucous lining); the excessive use of meat and eggs and like foods, which can be eaten rapidly with relative impunity, and the corresponding neglect of other foods, like bread, grains, vegetables, and salads, which require more mastication (and hence intestinal poisoning).

Prolonged Relish of Food

The habit of insufficient mastication is subtle, because it has become "second nature" with most of us. To free ourselves of it we must first of all allow plenty of time for our meals and rid our minds of the thought of hurry. A boy's school in which the principal is endeavoring to fight the habit of food-bolting has wisely ordained that no boy may leave the dining-room until a certain hour, even if he has finished eating long before. In this way the boy soon learns that there is nothing to be gained by fast eating, and, in fact, that the pleasantest way of spending the meal-time is to prolong the relish of the food. It would be well if all of us would adopt a similar rule for ourselves. Mr. Gladstone did something of the sort and was noted for the slow mastication of his food. Latterly Mr. Horace Fletcher set such a rule for himself, and revived the interest of the public in the subject.

The First Three Mouthfuls

At first one must give some conscious attention to his efforts to reform; but if one will merely attend carefully to the first three mouthfuls of a meal, the slow pace can often be established for the rest of the meal without further thought.

Careful Tasting

Slow eating is important not merely as a matter of mastication, but also as a matter of taste and enjoyment. Food must have a pleasing taste and flavor and then must be enjoyed in order to be most readily assimilated.

Increased Enjoyment

There is a mistaken notion that the hygiene of food means "giving up all the things that taste good." While it is true that, in many cases, sacrifices have to be made, the net result of reforming one's diet is not to diminish but to increase the enjoyment of food. In general, it is extremely unhygienic to eat foods which are not relished. Experiments by Pavlov and others have shown that the taste and enjoyment of food stimulate the flow of digestive juices.

Choosing Foods

Finally, slow eating is a great aid in the proper choice of foods. Some suggestions have already been given as to the wise choice of foods, but no rules can be formulated which will completely insure such a choice. Even the wisest physiologist can not depend altogether on his knowledge of food values, while, to the layman, the problem is so complicated that his main reliance must be on his own instincts. Animals depend exclusively on instinct except when under domestication. Civilized man should not and can not altogether depend upon instinct, but his food instincts are far more keen and correct if he obeys the rule of eating slowly than if he bolts his food.

"Good" and "Bad" Foods

In the choice of foods it is as difficult to distinguish absolutely between what are "good" and "bad" foods as it is to classify human beings into "good" and "bad." All we can say is that some foods are better than others, remembering that it is usually more important to be satisfied, even if the foods are not "ideal," than to be unsatisfied with what in the abstract seem "ideal" foods.

Among the best foods for most people are fruits, potatoes, nuts (if well masticated), milk, sour milk, and vegetables. Among the worst foods are putrefactive cheeses, sweetbreads, liver, kidneys, "high" game or poultry.

But a fastidious study of foods will find some faults as well as some virtues in almost any food. The best way to help the ordinary man choose his foods is to advise him to use as much as possible of the "better" and as little as possible of the "worse" without attempting to draw a hard and fast line between the "good" and "bad."

Salt, Pepper, Spices

Salt, pepper, and hot condiments should be used very sparingly, if at all.

Sugar and Candy

A great cause of ill health is overuse of sugar in concentrated form, candy, etc., especially by the sedentary. One reason why sugar has a high food value is that it is readily utilized for combustion, and if taken between meals greatly increases the calories and may lead to overnourishment.

Water with Meals

There is, for normal people, no objection to drinking a moderate amount of water at meals-say one or two glassfuls-provided it is not taken when food is in the mouth and used for washing it down.

The Digestibility of So-called "Indigestible" Foods

The science of dietetics will develop rapidly in the future, and in a few years it will probably be possible to be more definite than we have been here. At present there is much unknown, especially as to how far our rules have to be modified for the particular individual. Personal idiosyncrasies have to be taken into account. Sometimes "What is one man's meat is another man's poison." On the other hand, many have mistaken ideas as to their own idiosyncrasies. For instance, many people think that nuts never agree with them, when the trouble really is that they do not masticate them properly. Many think peanuts indigestible, not realizing either the importance of mastication or the importance of avoiding over-roasting. The ordinary peanuts are over-roasted. Peanuts very slightly roasted and very thoroughly masticated seldom disagree with one. Others believe that bananas never agree with them, when the fact is they eat them too green. The banana vender usually finds that the ignorant public buys his fruit best when its color is an even yellow, and he puts aside for himself the only bananas ripe and fit to eat, namely those which are mottled with black.

Avoidance of Fads

Each individual must use his own intelligence and common sense, avoiding so far as he can the mistake of following a "fad" and accepting a theory without sufficient evidence; and the opposite mistake of accepting as hygienic the customs about him simply because they are customs, and thus mistaking for fads any conclusions of science which are discordant with current custom.

Necessity of Medical Examination

It is a good idea to consult a physician in regard to one's diet, and endeavor intelligently to follow his advice and not insist on one's own diet, selected from the standpoint of mere self-indulgence or custom. Moreover, since many, without being aware of the fact, are affected with Bright's disease, diabetes, etc., in their early stages, in which dietetic precautions are especially necessary, it is well, even for those who are apparently in good health, to be medically examined as a preliminary to a rearrangement of their diet along the best lines.

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