What to eat and when

by Susanna Cocroft

FOOTNOTES:

[9] C. F. Langworthy, Ph.D.—In charge of Nutritive Investigations of the United States Experiment Station.

CHAPTER VIII
FOOD REQUIREMENTS OF THE SYSTEM

As previously stated, the object of foods is:

To supply the needs of the body in building new tissue as in the growing child.

To repair tissue which the catabolic activity of the body is constantly tearing down and eliminating; and

To supply heat and energy.

The heat and energy are not alone for muscular activity in exercise or movement. It must be kept in mind also that the body is a busy workshop, or chemical laboratory, and heat and energy are needed in the constant metabolism of tearing down and rebuilding tissue and in the work of digestion and elimination.

In this chapter, a few points given in the preceding pages are repeated for emphasis.

The proteins represented in purest form in lean meat build tissue, and the carbonaceous foods, starches, sugars, and fats, supply the heat and energy.

An excess of proteins, that is, more than is needed for building and repair, is also used for heat and energy.

The waste products of the nitrogenous foods are broken down into carbon dioxid, sulphates, phosphates, and other nitrogenous compounds, and excreted through the kidneys, skin, and the bile, while the waste product of carbonaceous foods is largely carbon dioxid and is excreted mostly through the lungs.

Since the foods richest in protein are the most expensive, those who wish to keep down the cost of living, should provide, at most, no more protein than the system requires. Expensive meats may be eliminated and proteins be supplied by eggs, milk, legumes, and nuts.

The fundamental thing is to decide on the amount of protein—two to four ounces, nearly a quarter of a pound a day—and then select a dietary which shall provide this and also supply heat and energy sufficient for the day.

If the diet is to include meat, a goodly proportion of protein will be furnished in the lean meat. This will vary greatly with the different cuts of meat, as shown in Table IV, page [54]. If, as often happens, one does not care for fats, then the starches and sugars must provide the heat. If much sugar is eaten less starches and fats are needed.

The normally healthy individual is more liable to take too much protein than too little, even though he abstain from meat.

If the diet is to include meat, it will be of less bulk, because the protein is more condensed; for the same reason, if it includes animal products of eggs and milk and a fair proportion of legumes, it will be less bulky than a vegetable diet. Yet unless vegetables, fruits, and plenty of water are consumed one must guard against constipation. This point is important for busy people who eat their meals in a hurry and proceed at once to active mental work.

Those who engage in physical labor are much more likely to take a complete rest for a half-hour, or an hour, after eating. The thinkers seldom rest, at least after a midday meal, and those who worry seldom relax the mental force during any waking hour; their brains are as active as those of mental workers.

Every housewife, to intelligently select the daily menus for her family, needs a thorough knowledge of dietetics. She must understand the chemistry of food that she may know food values.

The difficulty which confronts the housewife is to provide a meal suited to the needs, tastes, or idiosyncrasies of the various members of her household. Peculiarities of taste, unless these peculiarities have been intelligently acquired, may result in digestive disturbances. As an illustration: one may cultivate a dislike for meat, milk, or eggs, as is often the case, and if the proteins for the family is largely supplied by these, the individual who omits them from the meal, eats too large a proportion of starches and sugars, and not sufficient protein—legumes, nuts, etc. If this is long continued the blood becomes impoverished and anemia is produced.

The relief lies in cultivating a taste for all foods.

In active work, more heat is liberated, thus more fat, starches, and sugar are required for the resupply. As previously stated, if an excess of starch (glycogen) is stored in the liver, or an excess of fat in the tissues, this excess is called on to supply the heat and energy when the fats and carbohydrates daily consumed are not sufficient for the day’s demands. This is the principle in reduction of flesh.

It is interesting to note that habits of combining foods are, perhaps unconsciously, based on dietetic principles.

Meats, rich in protein, are served with potatoes or with rice, both of which are rich in starch.

Bread, containing little fat, is served with butter.

Beans, containing little fat, are cooked with pork.

Starchy foods of all kinds are served with butter or cream.

Macaroni, which is rich in starch, makes a well-balanced food when served with cheese.

Pork and beans, bread and butter, bread and milk, chicken and rice, macaroni and cheese, poached eggs on toast, and custards, form balanced foods.

A knowledge of such combinations is important when one must eat a hasty luncheon and wishes to supply the demands of the body in the least time, giving the least thought to the selection; but hasty luncheons, with the mind concentrated on other things, are to be strongly condemned.

It has been estimated that the average daily need of the adult is forty-five ounces of solid food, one-fourth animal and three-fourths vegetable. Twice as much water as solids should be taken.

The laborer, engaged in heavy muscular activity, needs and can assimilate more than the sedentary office worker. Those who work but a few hours a day require less food, as a rule, than those who work long hours.

Cold weather demands more heat-producing foods; a hot climate, inducing inactivity of body, diminishes the need for food.

The invalid needs less food than the healthy.

The inhabitant of the frigid zone needs much fat; he who lives in the tropics but little fat.

The old need less food than the growing youth or the hearty adult.

The poor must often take what he can get while the rich eat to satiety. Yet all these food needs vary with the individual and with the sex and activity.

It has been computed that the system needs daily three hundred grains of nitrogen and four thousand eight hundred grains of carbon. To obtain this amount of nitrogen if bread alone were eaten it would require four pounds of bread from the whole wheat. The carbon in this amount of bread largely exceeds that required. If eaten alone, six pounds of beef would be necessary to supply the proper amount of carbon, and twenty-three pounds of eggs. The nitrogen in this amount would far exceed the requirement.

One pint of milk, 2¹/₂ ounces of bread, and six ounces of beef are about equal in nutritive value.

One can see, therefore, why a diet composed of too great a quantity of one substance gives an overbalance of one and an underbalance of another.

Therefore, it is more economical to use some fat and sugar in the diet and less meat. More vegetables, perhaps, and more fluid should be taken by many.

Authorities vary in their estimates of the amount of food required by the individual. It varies with the activity, the season, the age, the sex, and it varies in the same individual on different days.

Billings estimates that the daily diet of a healthy, hard-working man should contain: 20 ounces (1¹/₄ pounds) of lean meat; 22 ounces, about 1¹/₃ pounds or 1¹/₃ loaves of baker’s bread; 10 ounces or about 4 medium sized potatoes; and several glasses of fluid. Since the fluid should be twice the amount of solids, this would mean about 12 glasses.

Others compute that the amount of food weighed dry, needed by the average person of sedentary habits, is as follows: For breakfast, 8 ounces; for luncheon, 6 ounces; for dinner, 9 ounces, with 48 ounces or 3 glasses of water. These two give extremes.

In active persons from 3 to 3¹/₂ ounces (about one-fourth of a pound) of nitrogenous food will replace the nitrogen lost from the body. One ounce (1¹/₁₆ of the ordinary brick) of butter a day supplies the necessary fat, and about 15 to 20 ounces (1 to 1¹/₄ pounds) of carbohydrate are required.

According to Thompson, from two to three pints of urine are excreted each day; ten ounces of water are lost by the lungs, and eighteen ounces are evaporated from the skin. This amount, about eighty ounces or ten glasses, must be replaced daily to maintain the body in its equilibrium of supply and demand. A part of this is supplied in the food.

These figures may be altered somewhat according to the individual or the climate as previously mentioned, but they constitute a fair average.

Dr. W. S. Hall estimates that the average man at light work requires,

each day	106.80	grams of protein[10]
	57.97	grams of fat
	398.84	grams of carbohydrates

These elements, in proper proportions, may be gained through many food combinations. He gives the following as an example:

Bread	1	lb.
Lean Meat	1/2	”
Oysters	1/2	”
Cocoa	1	oz.
Milk	4	ozs.
Sugar	1	oz.
Butter	1/2	”

A medium-sized man at out-of-door work, fully oxidizes all waste of the system and he requires a higher protein diet—125 grams. In such event he does not require so much starch and sugar. If, on the other hand, he were to take but 106.8 grams of protein, as above, he would require more carbohydrates. One working or exercising in the fresh air breathes more deeply and oxidizes and eliminates more waste, hence he has a better appetite, which is simply the call of nature for replacing the waste.

Experiments in the quantity of food actually required for body needs, made by Prof. R. H. Chittenden, of the Sheffield Scientific School, Yale University, have established, beyond doubt, the fact that the average individual consumes very much more food than the system requires. In fact, most tables of food requirements, in books on dietetics, are heavy, yet the amount of food required as a result of Professor Chittenden’s experiments would seem to be too light for a continuous diet.

Professor Chittenden especially established the fact that the average person consumes more protein than is necessary to maintain a nitrogenous balance. It was formerly held that the average daily metabolism and excretion of nitrogen through the kidneys was sixteen grams, or proportionate to about one hundred grams of protein or albuminoid food.

Professor Chittenden’s tests, covering a period of six months, shows an average daily excretion of 5.86 grams of nitrogen, or a little less than one-third of that formerly accepted as necessary; 5.86 grams of nitrogen corresponds to 36.62 grams of protein or albuminoid food.

Professor Chittenden’s experiments concerning the amount of foodstuffs actually required by three groups of men, one group of United States soldiers, a group from the Yale College athletic team, and a group of college professors, all showed that the men retained full strength, with a higher degree of physical and mental efficiency, when the body was not supplied with more protein than was liberated by metabolic activity, and when the quantity of carbonaceous food was regulated to the actual requirements for body heat and energy.

It may be well to call attention here to the fact that most of the food elements, called on for work, are not derived from those foods just consumed or digested, but from those eaten a day or two previous, which have been assimilated in the muscular tissues.

Dr. W. S. Hall gives the rations for different conditions, as shown in the following tables:

TABLE XI
Rations in Different Conditions

CONDITIONS	Proteins		Fats	Carbohydrates		Energy in Calories
	Low	High		Low	High
Man at light indoor work	60	100	60	390	450	2764
Man at light outdoor work	60	100	100	400	460	2940
Man at moderate outdoor work	75	125	125	450	500	3475
Man at hard outdoor work	100	150	150	500	550	4000
Man at very hard outdoor winter work	125	180	200	600	650	4592
U. S. Army rations	64	106	280	460	540	4896-5032
U. S. Navy rations	...	143	292	557	...	5545
Football team (old régime)	...	181	292	557	...	5697
College football team (new)	125	125	125	500	...	3675

TABLE XII
Rations Varied for Sex and Age

VARIATIONS OF SEX AND AGE	Proteins		Fats	Carbohydrates		Energy in Calories
	Low	High		Low	High
Children, two to six	36	70	40	250	325	1520-1956
Children, six to fifteen	50	75	45	325	350	1923-2123
Women with light exercise	50	80	80	300	330	2272
Women at moderate work	60	92	80	400	432	2720
Aged women	50	80	50	270	300	1870
Aged men	50	100	400	300	350	2258

The unit of measurement for the calories of energy is the amount of heat required to raise the temperature of one kilogram of water from zero to 1° centigrade or 4° Fahrenheit.

In estimating the number of calories of energy given off by the different foods, Dr. Hall represents

1	gram of	carbohydrates	as	4.0	calories
1	” ”	fats	”	9.4	”
1	” ”	proteins	”	4.0	”

To determine the relative energy which a food represents, it is only necessary to multiply the number of grams of protein in that food by 4, the fat by 9.4, and the carbohydrates by 4, and add the results.

Thus according to the food required for the average man at light work given on page [225]:

106.80	grams of	proteins	×	4 =	427.20 calories of energy
57.97	” ”	fat	×	9.4 =	544.94 ” ” ”
398.84	” ”	carbohydrates	×	4 =	1595.36 ” ” ”
					2567.51 = the calories of energy required for the average man at light work.