How to Live Part 3

FOOD

Section I--Quant.i.ty 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.

[Sidenote: 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, cuc.u.mbers, 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 b.u.t.ter (about an ounce); in a quarter of a gla.s.s of cream (about 2 ounces); in a small gla.s.s 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.

[Sidenote: 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 a.s.sociated 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.

[Sidenote: 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 cla.s.s that life insurance companies have found to be undesirable as risks.

[Sidenote: Accessories]

One reason why many people eat great quant.i.ties 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 b.u.t.ter 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 acc.u.mulates 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 acc.u.mulated in the body.

[Sidenote: 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 a.s.similate the food, while overfatigue and exhausting physical exertion should be carefully avoided.

[Sidenote: 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.

[Sidenote: Diet in Hot Weather]

Generally the quant.i.ty 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 a.s.sume that sufficient food is taken.

[Sidenote: 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.

[Sidenote: 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

[Sidenote: Protein, Fat, and Carbohydrate]

In the last section it was stated that food is fuel. But there is one const.i.tuent 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 const.i.tuent in food is called protein. The two other chief const.i.tuents 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 b.u.t.ter, oleomargarine, oil, lard, and cream--which consist of fat (and water)--and sugar, sirups, and starch, which consist of carbohydrate (and water).

[Sidenote: 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.

[Sidenote: 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 a.n.a.lysis 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 a.n.a.lysis 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.

[Sidenote: 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, sh.e.l.l-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.

[Sidenote: 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 quant.i.ties 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.

[Sidenote: Animal Proteins]

Flesh food--fish, sh.e.l.l-fish, meat, fowl--when used in great abundance, are subject to additional objections. They tend to produce an excess of acids, are very p.r.o.ne 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.