Open main menu

Popular Science Monthly/Volume 83/October 1913/Scientific Standards for the Governmental Regulation of Foods

SCIENTIFIC STANDARDS FOR THE GOVERNMENTAL REGULATION OF FOODS
By JOHN R. MURLIN, A.M., Ph.D.

ASSISTANT PROFESSOR OF PHYSIOLOGY, CORNELL UNIVERSITY MEDICAL COLLEGE, NEW YORK CITY

THUS far in our attempts to regulate by law the purity of foods admitted to interstate commerce, practically no attention has been paid to the real physiological economy of foods. Questions of purity, of what constitutes an adulterant, "What is ice cream?" etc., have been much before the public and much before the courts. The bone of contention in most cases has been not how much food value does a given product contain, but is it properly labeled or is it adulterated?

From the strictly legal point of view anything is an adulterant which belies the label; but from the physiological point of view nothing is an adulterant unless it really impairs the food value. Jams made with commercial glucose instead of cane sugar might very properly be excluded from commerce under the law as it stands, unless the label states clearly the fact that glucose is contained; but such jams would have exactly as much food value as if made of ordinary sugar, for glucose yields as much energy to the body as does cane or beet sugar. Similarly, nobody likes to be defrauded even in a technical sense and get oleomargarine under the label of butter, but how does the matter stand if oleo proves to be just as nutritious as butter? Is it not time there were an adequate standard for judging of food values? Should not the food manufacturers—those who put up foods in packages and sell them under protected trade marks be required to correctly express on the label the real physiological value of their products? If the purchaser has a choice of oleo plainly labeled at 25 cents a pound or of butter properly so designated at 40 cents a pound, what determines his choice? First of all, probably, the taste. But if it were practicable to show also the relative food value of the two parcels, would not this factor enter into his decision, and is not the purchaser entitled to this information? Similarly with other kinds of food. Take the cereal breakfast foods. Their number is legion. How is the purchaser to make an intelligent selection? At present the only way is first to buy and try the taste, the "lasting qualities," etc. But if it were possible to learn from the label its fuel value the housekeeper would be able to select from the staple articles either the most pleasing or the most nourishing foods.

According to the best scientific information to-day foods serve two main purposes in the animal economy: (1) They supply building and repair materials, and (2) they furnish energy for all the physiological activities. Let us consider the latter purpose first. Physiologists have demonstrated by numerous experiments that all the energies manifested in the body finally leave the body as heat which can be measured by an instrument known as the calorimeter. The heat unit employed in these calculations is known as a calorie, which is the amount of heat necessary to raise one kilogram of water 1° Centigrade. The quantity of heat measured agrees exactly with the quantity which may be calculated from the known amount of oxidation of foodstuffs which has taken place in the body. When muscular work is done in a calorimeter and the work is all made to take the form of heat, the increased heat production is again what it should be as judged by the increased oxidation. Similarly, the energy value of foods is determined either by analysis and computation or by burning it in oxygen. Given then foods capable of producing a certain quantity of heat, it is a fairly easy task to compute the amount of each which would be necessary to furnish the energy requirements of the body under any given set of conditions.

An engineer who wishes to supply a certain amount of power must know the heat value of certain kinds of fuel and the waste from each. From these he reckons the net cost of his power. Any one who cares to do so can make the same sort of a computation for his body. If the engineer pays $7 for a ton of coal, he sees to it that he gets $7 worth of heat. Why is it not just as reasonable when a person pays a certain price for food to expect a certain amount of food value? To demand the worth of one's money in heat units when the fuel in the house is under consideration is a plain proposition, and when housewives generally understand food values it will be a plain proposition in respect to fuel for the body. A properly educated public opinion will demand from manufacturers such information in regard to the food on which its energies depend.

Let us see if this is not a practical suggestion, and whether, after all, it may not prove a simple solution to a supposedly difficult problem. If our foods were all simple substances like sugar or olive oil, and if the energy content of the food were the only one of which we need take any account, the problem would be just as easy as calculating the yield of energy in horse-power from a ton of coal. It is because our foods are mixtures of various foodstuffs, each having a different fuel value and a different functional value, that the matter requires some study.

The simplest method yet devised for keeping account of the energy supply in one's diet is that devised by Professor Irving Fisher, of Yale University. The idea underlying this method is to do away with intricate calculation by familiarizing one's self with the amount of each article of food, as purchased or as served on the table, which yields 100 calories of energy. This he has called the "standard portion."[1]

Often it happens that the quantity required to make a standard portion is a very convenient amount to serve on a plate. One large egg, weighing 2 ounces, is almost exactly a standard portion. An ordinary serving of butter (1/2 ounce), a teaspoonful of olive oil, one large orange, one large banana, one medium thick slice of white bread—each contains very nearly 100 calories of energy. By an easy computation one can readily learn the exact weight of any kind of food whose composition is known, which will yield 100 calories. It would help greatly if some enterprising manufacturer were to place on the market standardized measures made in metal for a standard portion of sugar, milk, rice, butter, oatmeal, flour, dried beans and any other food which does not vary much in composition. The only difficulty with this method is that certain food products as purchased in the market differ considerably in composition. It would therefore be much simpler for the consumer if the food manufacturer were required to guarantee not only the purity of his product in the ordinary sense, but to guarantee also a certain energy content. If, for example, a certain brand of oatmeal bore on its label the statement, "This package is guaranteed to contain 2,000 calories of heat energy," this information would be worth many times as much to the purchaser as the statement, "This food is guaranteed to comply with the food and drugs act," etc. For he would then have some basis upon which to judge the actual economy of his purchase. Some other product likewise "guaranteed to contain 2,000 calories" might cost him only one half as much.

Such a guaranty would entail no great hardship on the part of the manufacturer, because it would involve the employment only of a competent chemist to make an occasional analysis, or a determination by combustion of the heat value. The law of many states already requires that milk admitted to the markets must not fall below a certain percentage of fat (cream). If the label on top of the bottle were required to state, "This bottle contains 650 calories of food energy," the legal requirement would mean something to the purchaser, for it would enable him to tell whether milk is or is not a cheap food as compared with, say, oatmeal or eggs.

A person must have a certain minimum of energy value in his food every day. There is no law of nature more inexorable than this. Certain faddists like Horace Fletcher have averred that they live on much less energy than does the average man, and yet when Mr. Fletcher was put into a calorimeter at Middletown, Conn., it was found that ho lost from his body nearly if not quite as much heat as the average man of his age and stature. To keep himself in an equilibrium of substance it would therefore be absolutely necessary for him to take at least this quantity of potential energy in the form of food.

A few months ago a certain New York daily widely advertised the light diet by sending on foot to Chicago a woman who claimed to be living on nuts, salads, orange Juice and the like. When she arrived at Chicago it was found that she weighed some 12 pounds less than when she left New York and yet the feat was declared to be a "triumph" of the woman's regimen of light foods. As a matter of fact she had not lived on these light foods alone, but had lived largely at the expense of her own body fat. In other words, she had a large part of her fuel for the trip already in storage. If the twelve pounds which she lost were all fat, as it probably was, this alone furnished a large part of the energy of walking for the forty days (I believe it was); for every ounce of fat burned from her own tissues gave about 250 calories of energy and in 12 pounds there would be 48,000 calories or about 1,200 calories a day. If she had added 4.8 ounces of fat or a little more than twice as much starch or sugar every day to her bill of fare she would have arrived in Chicago weighing as much as when she left New York.

Cold weather raises the requirement for energy, for the body loses more heat to its environment, unless this heat is kept in by warm rooms or warm clothing. The law of energy requirement applies most severely therefore to those who can least afford to buy a large supply of food. How important it is that their money should be made to go as far as possible! The pure-food law at present operates to protect those who use more highly flavored foods and drinks rather than the poor. If every kind of food purveyed in packages, tins, bottles, etc., bore a label stating its energy value the poor and all would soon learn how to make the money go farthest.

When it comes to the actual task of calculating the body's requirements it is customary to begin with minimal conditions. A person, uses the least energy when he is resting and fasting and is kept warm—lying in bed for example. When he moves about—that is, does muscular work, when he digests a meal, or when he is exposed to cold, he uses more energy. The average utilization in twenty-four hours under minimal conditions is about fourteen calories per pound of actual body weight, or for a man of average weight (154 lbs.) 2,150 calories. We should not miss it far if we should say that a person sitting up would use one calorie per pound more (2,300). And if he digests three meals a day he uses an additional calorie per pound (2,450). If, now, he does light muscular work, like typewriting, he uses about 25 calories per hour for this work, or in eight hours 200 calories, making the total for a man of average weight 2,650 calories.

If the person's work requires him to walk about all day, instead of sitting still and using his arms, he, of course, does the work of carrying his body, to say nothing of the other things he may carry, and the allowance must be three or four times as great as in the case of typewriting. A soldier on the march, walking less than three miles an hour, has been found to use 160 calories per hour for the muscular work alone. Most occupations which involve walking are less exacting because there are frequent rest periods. So, if we allow 75 calories per hour, it will probably supply the extra energy requirement over that of complete muscular rest, for, say, a fairly active salesman. This total intake in three meals, if he is of average weight, would be some 400 calories (four standard portions) more than that of the office worker. Two sample diets constructed so as to contain the twenty-four-hour requirements for the office worker and the salesman, respectively, are given below:

TABLE I
Full Daily Supply of Energy for a Salesman of Av. Weight (154 lbs.) Full Daily Supply of Energy for an Office Worker of Average Weight

PSM V83 D352 Nutrition requirements for light physical exertion part 1 of 2.png

PSM V83 D353 Nutrition requirements for light physical exertion part 2 of 2.png

It will be clear from what has been said above that the requirements of the body for muscular labor in winter will depend on whether a person works indoors or out. Lumbermen who work in the north woods in winter probably require more food than any other class of laborers. At the opposite extreme, so far as external conditions are concerned, stand the men who work in factories, beside furnaces, etc. Their muscular work may be just as heavy as that of the lumberman, but their bodies are kept warm by artificial heat. The problem for them, as for ordinary laborers outdoors in hot weather, is rather that of removing the extra heat of muscular work.

Between these two extremes, naturally, are people who are subjected to conditions of all degrees of severity It is impossible to prescribe a day's dietary which will fit all of them. We select a teamster and a foundryman of average weight. The former we suppose not only does the heavy muscular work of lifting boxes and cases, but is exposed to cold winds and rains. The latter does heavy work but is kept warm at his task.

A person who follows his natural craving will find himself eating more meat, especially more fat meat, in winter than in summer. This is not merely because fat meat contains more energy for the same weight than starchy foods, but because foods rich in protein and fat stimulate the processes of combustion by which heat is produced. For example, a day's diet consisting of nothing but lean meat would increase the heat production by about 30 per cent. The same diet consisting exclusively of starchy foods would increase it only about 5 per cent. This is the reason why laborers in the open crave meats more than do those who work indoors.

TABLE II
Sample Diets for a Teamster and a Foundry Worker
Full Daily Supply of Energy for a Teamster of Average Weight Full Daily Supply of Energy for a Foundry Worker of Av. Weight

PSM V83 D353 Nutrition requirements for heavy physical exertion part 1 of 2.png

PSM V83 D354 Nutrition requirements for heavy physical exertion part 2 of 2.png

That this energy-giving quality of foods is the most important function which they serve is apparent at once when we discover that at least four fifths of the dry weight of our food serves no other purpose than that of giving heat. The heat comes from the oxidation of our food and since the temperature of the air about us is nearly always lower—in winter very much lower—than blood heat, we are practically always losing heat by radiation and conduction. Merely to keep up the body temperature to 98° F., the temperature at or near which the living substance best performs its functions in every animal, is the purpose of the great mass of fuel which we are obliged to "supply" every day of our lives. To furnish the energy for the muscular work which most of us do requires relatively little and, strangely enough, to supply brain energy—intellectual energy, alertness and other purely psychic qualities—apparently requires no energy at all in the sense in which we have been using that term thus far. Experiments have been conducted on college students while writing a very difficult examination, and it was found that no more energy was set free from the body than when they were simply writing nonsense. However, a very small part of the potential energy of the food always takes the form of electrical energy and elec- trical energy is manifested whenever nervous tissue (brain, nerve, etc.) is active. It is possible then that the reason no extra heat energy was given off from the body when the brain was working hard is because this electrical energy simply took the place of other forms of energy (like the secretory processes of glands, etc.), in which case it would not be correct to say that brain work is not done at the expense of potential energy. The subject requires much more study than has yet been given to it.

It will be evident from the discussion thus far that it is the energy content of the food which a person is concerned primarily to know in order to judge the economy of its use. Ordinarily if one takes care merely to supply himself enough heat energy and takes care also to eat a variety of food the other requirements will be automatically regulated by the appetite. Failure properly to adjust the energy supply to the actual requirements result in depletion which may subject one to disease, or, on the other hand, may lead to obesity.

But it would be a serious mistake to ignore the other chief purpose of foods — namely, their value as tissue builders and restoratives. 'While not more than one fifth of the dry weight of our foods find a permanent lodgment in the body, it is obvious that the functional activity of the tissues could not be kept up indefinitely without these constituents of which tissues are formed. Still less could growth of the body in early life be maintained.

Among these constituents the most important is that class of sub- stances known to physiologists as proteins, exemplified by the white of egg, the casein of milk, the gluten of bread and par excellence the flesh of animals. The actual requirement of the body for these substances is much less than is ordinarily supposed. In starvation, when the body is living at the expense of its own substance, about 13 per cent, of its energy is derived from the breakdown of proteins or the nitrogenous substances. The remaining 87 per cent, is derived from the body fat and glycogen, which is the form in which the body stores up starches and sugars. Theoretically the body would be kept in perfect equilibrium then if the food contained 87 per cent, of the total energy in the form of carbohydrates and fats and 13 per cent, in the form of protein. In fact, many persons have found that they keep in better physical condi- tion if they take somewhat less than 13 per cent, in the form of protein, for with a generous suply of carbohydrate in the food the waste of proteins from the body is considerably less than in starvation. The dietaries suggested above for various sorts of workers, however, have been constructed on the basis of about 13 per cent, protein calories, to be on the safe side.

It would be most desirable, therefore, if the label on packages of manufactured foods were required to give also the content of protein in addition to the total energy value. This might be done in the case of oatmeal as follows: "This parcel is guaranteed to contain 2,000 calories of heat-value, of which 14 per cent, is in the form of protein," or, in the case of milk, "700 total calories, 16 per cent, protein calories." Naturally the milk would not yield 700 calories to the bottle unless it were high in cream. The relation of total calories to protein calories might also be expressed in the form of a ratio.

A law requiring the correct labeling of foods with reference to the energy content and protein content should result in a wholesome competition among producers and manufacturers to improve the actual food value and therefore their real economic value. At present the competition runs along the line of the appearance of food and mere flavor, which, although desirable, are not the most necessary qualities to be considered in the provisioning of our people. Coal and other forms of fuel for our boilers and automobiles we must take as we find them in the earth. The only way in which we can improve their quality is by refinement, which costs nearly as much as we gain. But in the matter of fuels for our bodies there are immense possibilities of improvement without increasing the cost a particle. The fuel value of a food crop depends upon the power of the plant to utilize primarily the carbon dioxide of the air and the water of the soil in the formation of sugars, starches and oils. Under the stimulus of the sunlight the energy-of the sun is stored up in roots, grains, etc., and is not lost until the food is burned in the animal body. So long as air and water and sunlight cost nothing an improved variety of corn or wheat or oats or rice which would yield more energy should be produced as cheaply as those we are now living upon, except for the extra thought and work of selection which might be involved. But the stimulus to produce more for the money for the sake of larger sales is exactly the sort of stimulus we want the food manufacturer to have.

A standard of purity in this sense ought to have the effect also of emphasizing the expensiveness of animal food as a source of energy as compared with vegetable food. For when the corn grown in one field is fed to an ox in another the ox dissipates fully nine tenths of the energy walking about the field and stores in his body for our use as food only the other one tenth. Hence to get our full energy requirement in the form of beef even the cheapest cuts would cost us at least ten times as much as it would if we ate the corn meal. This is assuming that the cost of preparing the two kinds of food for the market, and finally for the table, is the same. The illustration is used only for the purpose of emphasizing the fact that animal foods as a source of energy are necessarily more expensive than plant foods. As a source of protein the comparison would not be so much to the disadvantage of meats.

Of course it is realized that as matters now stand a great deal of our food budget is spent for pure flavor. Flavor in the broad sense is "anything which adds the element of pleasure to a meal." Chemical flavor which affects the olfactory organ or the taste buds serves a useful purpose at times in stimulating the flow of digestive secretions in anticipation of a meal and at times it serves a harmful purpose in causing us to overeat. The appearance of the food either in the parcel or on the table may serve as flavor. The kind of service, the presence of good company or even music come under the same head. If one can digest a meal only when accompanied by these latter kinds of flavors they are perhaps justifiable, but from the standpoint of the national welfare they do not deserve much consideration. Appreciation of food and the full physiological effect of flavor are obtainable by the simple device of getting thoroughly hungry before we eat.

The writer once had occasion to compare the actual food value of a dinner served at "Joe's" on Third Avenue for thirty cents and a five-course dinner served three blocks further west at a cost of three dollars. The advantage in actual food value lay with the former. The difference in cost was due entirely to "flavor."

The state universities of the wheat and corn growing sections of this country with the help and encouragement of the Department of Agriculture have already inaugurated an enthusiastic campaign for the production of better wheat, greater yield of corn per acre, and improved varieties of other food products. The classes in domestic science in public schools are learning food values as few of the present generation had any opportunity to learn them. Similar instruction has been given to working girls in the settlement houses. The time is certainly not far distant when the food manufacturer must keep pace with this rapidly increasing knowledge of food values and must make it possible for the housekeepers to know exactly what energy is stored in the food they buy. Some states, New York, for example, require cattle foods to be so labeled now. Human food may contain anything so long as it is "pure."

The government might well establish a classification of foods such as: (1) Foods which are wholly or chiefly energy-producing; (2) foods which are wholly or chiefly tissue-building and (3) foods which are of use chiefly as flavors. In the first class would belong sugar (which is usually thought of as a flavoring material), cornstarch, olive oil, butter, etc.; in the second would belong eggs, meat, cheese, etc.; and in the third would belong pickles, catsups, sauces, tomatoes. Foods which in reality belong to more than one class, as milk, oatmeal, green beans, etc., could be assigned according to their analyses and according to the judgment of a referee board of physiologists, which would then have a constructive economic function to perform instead of a reviewing function which has been discharged by the Remsen Board; for to determine the real physiologic and therefore the real economic value of certain foods would require long and careful experimentation. The regulations as to labeling would naturally be different for the different classes.

Obviously there should be no relaxation of the present vigilance of the law as to preservatives which have been proved harmful, nor as to the permission of unwholesome constitutents nor as to the presence of adulterants—meaning by that term anything which reduces or impairs the food value. But the bureau of chemistry of the Department of Agriculture should be enlarged into a bureau of food economics so that its function should become more constructive in the sense in which the bureau of plant industry and the bureau of animal husbandry is more economic. It has become a truism that the government pays more attention to the health of pigs than it does to the health of men. Unless we mistake the spirit of true progressivism this will not properly express the functions of government a generation hence. A very material advance, educative in its influence and highly economic in its results, would be the establishment of this new standard of purity in foods.

  1. By writing to the Superintendent of Documents at Washington the careful student of the problem can have a list of publications on foods. Bulletin No. 28 of the Department of Agriculture, published in 1906, price five cents, entitled "Composition of American Foods," by Atwater and Bryant, contains nearly all the information required regarding the fuel value of the common articles of food.