The nutrition of man

PRACTICAL APPLICATIONS WITH SOME ADDITIONAL DATA

Topics: Proper application of the results of scientific research helpful to mankind. Dietary habits should be brought into conformity with the true needs of the body. The peculiar position of proteid foods emphasized. The evil effects of overeating. What the new dietary standards really involve. The actual amounts of foodstuffs required. Relation of nutritive value to cost of foods. The advantages of simplicity in diet. A sample dietary for a man of 70 kilograms body-weight. A new method of indicating food values. Moderation in the daily dietary leads toward vegetable foods. The experiments of Dr. Neumann. The value of fruits as food. The merits of animal and vegetable proteids considered in relation to the bacterial processes in the intestine. A notable case of simplicity in diet. Intelligent modification of diet to the temporary needs of the body. Diet in summer and winter contrasted. Value of greater protection to the kidneys. Conclusion.

Knowledge has value in proportion to the benefit it confers, directly or indirectly, on the human race. Every new scientific fact or principle brought to light promises help in the understanding of Nature’s laws, and when rightly interpreted and properly applied is sure to aid in the advancement and prosperity of the individual and of the community. Proper methods of living, economical adjustment of the intake to the varying needs of the body, avoidance of excessive waste of foodstuffs and of energy, are all desirable precepts, which rational people presumably are inclined to follow so far as their knowledge and understanding of the subject will permit. Here, as elsewhere, false teaching may be exceedingly mischievous and lead to costly errors; while blind reliance upon customs, instinct, and superstitions is hardly in keeping with twentieth-century progress.

Modern scientific methods should give us help in dietetics, as in other branches of hygiene and practical medicine. A few short years ago, diphtheria was a scourge which brought misery to many a home, for there was at hand no adequate means of combating the disease; but scientific research has given us new light, and placed at our command a weapon of inestimable value. Do we hesitate to use it when the occasion arises, because it happens to be out of keeping with old-time customs and traditions? No, we recognize the possibility of help, and as the need is urgent we turn to it quickly, with hope and thankfulness that scientific progress has opened up a pathway of escape from a threatened calamity.

Not many years ago we drank freely of such water as was at hand, without realization of danger from bacteria or disease germs, looking on epidemics of typhoid fever perhaps as a visitation of Divine Providence, in punishment of our many sins and to be borne meekly and with resignation. But all this has changed through the researches of bacteriologists and chemists; scientific facts of the utmost importance have been clearly established; a classification of water-borne diseases has been adopted, and we realize fully that diseases of this order can be kept from our doors by proper precautions applied to our water supply. To-day, epidemics of typhoid fever are traceable solely to the ignorance or carelessness of the individual or of the commonwealth, and the exemption which we of the present generation have from this class of diseases is directly due to the application of precautionary measures based on the information furnished by scientific investigation. It is proper for us to use caution in the acceptance of new ideas, but not that form of caution which refuses change on the ground that what has been is sufficiently good for the present and the future. The point of view is ever changing with advance of knowledge, and it is not profitable to exclude opportunities for improvement in personal hygiene and general good health, any more than in other matters that affect the prosperity of the individual or the community.

Dietary habits should be brought into conformity with the true needs of the body. Excessive consumption of proteid food, especially, should be avoided on the ground that it is not only unnecessary and wasteful, but is liable to bring penalties of its own, most undesirable and wholly uncalled for. We may, perhaps, accept these statements at their full value, and yet have a shadow of doubt in our minds as to whether, after all, dietary customs do not harmonize sufficiently at least with true nutritive requirements. All the data that we have presented in the preceding chapters, however, have seemingly given a positive answer to such doubts, and indicate quite clearly that the results of scientific study are opposed to the prevailing dietary standards, especially as regards proteid food. As the celebrated physiologist Bunge has expressed it, “The necessity for a daily consumption of 100 grams of proteid is incomprehensible, so long as we do not know of any function of the body in the performance of which the chemical potential energies of the destroyed proteid are used up.”

Perfectly trustworthy evidence is at hand showing that the needs of the body for potential energy can be fully met, and indeed are more advantageously met, by the non-nitrogenous foods, carbohydrates and fats. The energy of muscle work, as we have seen, comes preferably from the breaking down of non-nitrogenous material, so that there is no special call for proteid in connection with increased muscular activity. In fact, it would appear that the need for proteid food by man is limited to the requirements of growth and development, reinforced by the amount called for in that form of tissue exchange which we have emphasized under the term “endogenous proteid metabolism,” or true tissue metabolism. To be sure, there must be a certain reserve of proteid, available in case of emergency, but this is easily established without resorting to excessive feeding.

The peculiar position which proteid foods occupy in man’s dietary naturally make them the central figure, around which the other foods are grouped. No other form of food can take the place of proteid; a certain amount is needed each day to make good the loss of tissue material broken down in endogenous katabolism, and consequently our choice and combination of the varied articles of diet made use of should be regulated by the amount of proteid they contain. But while proteid foods occupy this commanding position, it is not necessary or desirable that they should exceed the other foodstuffs in amount, or indeed approach them in quantity. We must be ever mindful of the fact, so many times expressed, that proteid does not undergo complete oxidation in the body to simple gaseous products like the non-nitrogenous foods, but that there is left behind a residue of non-combustible matter—solid oxidation products—which are not so easily disposed of. In the forceful language of another, “The combustion of proteid within the organism yields a solid ash which must be raked down by the liver and thrown out by the kidneys. Now when this task gets to be over-laborious, the laborers are likely to go on strike. The grate, then, is not properly raked; clinkers form, and slowly the smothered fire glows dull and dies” (Curtis).

Even though no such dire fate overtakes one, the penalties of excessive proteid consumption are found in many ills, for which perhaps the victim seeks in vain a logical explanation; gastro-intestinal disturbance, indigestion, intestinal toxæmia, liver troubles, bilious attacks, gout, rheumatism, to say nothing of many other ailments, some more and some less serious, are associated with the habitual overeating of proteid food. But excessive food consumption is by no means confined to the proteid foodstuffs; general overfeeding is a widespread evil, the marks of which are to be detected on all sides, and in no uncertain fashion. One of the most common signs of excessive food consumption is the tendency toward obesity, a condition which is distinctly undesirable and may prove decidedly injurious. Undue accumulation of fat is not only a mechanical obstacle to the proper activity of the body as a whole, but it interferes with the freedom of movement of such muscular organs as the heart and stomach, thereby interposing obstacles to the normal action of these structures. Further, whenever undue fat formation is going on in the body, there is the ever present danger that the lifeless fat may replace the living protoplasm of the tissue cells and so give rise to a condition known as “fatty degeneration.” While a superabundance of fat in the body is a sure telltale of overeating, the absence of obesity is by no means an indication that excess of food is being avoided. There is here, in man as in animal kind, much idiosyncrasy; some persons, especially those endowed with a long and large frame, tend to keep thin even though they eat excessively, while others grow fat much more readily. As a well-known physician has expressed it, “In the one case, the subject burns, instantly and mercilessly, every stick of fuel delivered at his door, whether or not he needs the resulting hot fire roaring within, while the other, miser-like, hoards the rest in vast piles, filling the house from cellar to garret.”

Temperance in diet, like temperance in other matters, leads to good results, and our physiological evidence points out plainly, like a signpost all can read, that there is no demand on the part of the body for such quantities of food as custom and habit call for. Healthfulness and longevity are the prizes awarded for the successful pursuance of a temperate life, modelled in conformity with Nature’s laws. Intemperance, on the other hand, in diet as in other matters, is equally liable to be followed by disaster. A physician of many years’ experience, with opportunities for observation among different classes of people, has written, “that overeating tends to shrink the span of life in proportion as it expands the liver is demonstrable both directly and indirectly. Let any actuary of life-insurance be asked his experience with heavy-weight risks, where the waist measures more than the chest, and the long-drawn face of the businessman, at memory of lost dollars, will make answer without need of words. Then let be noted the physique of the blessed ones that attain to green old age, and, in nine cases out of ten, spry old boys—no disparagement, but all honor in the phrase—will be found to be modelled after the type of octogenarian Bryant or nonogenarian Bancroft—the whitefaced, wiry, and spare, as contrasted with the red-faced, the pursy, and the stout. It is true, as has already been mentioned, that in old age much of an adventitious obesity is absorbed and disappears, but the Bryant-Bancroft type is that of a subject who never has been fat at all. And just such is preëminently the type that rides easily past the fourscore mark, reins well in hand, and good for many another lap in the race of life.”75

With these thoughts before us, we may consider briefly just what is involved in these new dietary standards that aim to conform more closely with actual body needs. Referring at first to proteid food, it may be wise to again emphasize the fact that the weight of the body, i. e., the weight of the proteid-containing tissues, as contrasted with excessive fat accumulation, is one of the important factors not to be overlooked when determining the dietary needs of a given individual. As must be perfectly clear, from all that has been said, the man of 170 pounds’ body-weight has more proteid tissue to nourish than the man of 130 pounds’ weight, and consequently what will satisfy the requirements of the latter individual will not suffice for the former. We must understand distinctly that no general statement can be made applicable to mankind at large, but due consideration must be given to the size and weight of the individual structure. We have found that the average need for proteid food by adults is fully met by a daily metabolism equal to an exchange of 0.12 gram of nitrogen per kilogram of body-weight. This means a katabolism of three-fourths of a gram of proteid matter daily, per kilogram.

Remembering, however, that the intake of proteid food must be somewhat in excess of the actual proteid katabolism, since not all of the proteid of the food is available, and as this is a variable amount depending upon the proportion of animal and vegetable foods with their different degrees of digestibility and availability, we may place the required intake of proteid at 0.85 gram per kilogram of body-weight, still keeping to maximum figures for safety’s sake. Hence, for a man weighing 70 kilograms or 154 pounds, there would be required daily 59.5 grams—say 60 grams—of proteid food to meet the needs of the body. These are perfectly trustworthy figures, with a reasonable margin of safety, and carrying perfect assurance of being really more than sufficient to meet the true wants of the body; adequate to supply all physiological demands for reserve proteid, and able to cope with the erratic requirements of personal idiosyncrasies. It will be observed that such an intake of proteid food daily is equal to one-half the Voit standard for a man of this weight, while it is still further below the Atwater standard and far below the common practices of the majority of mankind in Europe and America, as indicated by the published dietary studies.

It may not be out of place to state at this point that in the writer’s opinion the use of the terms “standard diet” and “dietary standards,” etc., is objectionable, since such usage seems to demand a certain degree of definiteness in the daily diet for which there is no justification. As in the use of the term “normal diet,” there is danger of misinterpretation, and of the assumption that dietary habits should be regulated strictly in accord with certain set principles. This I believe to be altogether wrong; there should be, on the contrary, full latitude for individual freedom, but freedom governed by an intelligence that appreciates the significance of scientific fact and is willing to mould custom and habit into accord with them. What is needed to-day is not so much an acceptance of the view that man requires daily 0.85 gram of proteid per kilogram of body-weight, as a full appreciation of the general principle, which our definite figures have helped to work out, that the requirements of the body for proteid food are far below the customary habits of mankind, and that there is both economy and gain in various directions to be derived by following the general precepts which this view leads to. In other words, there is no advantage, but, on the contrary, much bother and worriment, in attempting to follow out in practice the details of our more or less exact physiological experiments.

The general teaching which they afford, however, can be adopted and put in practice in our daily lives, without striving to follow too closely the so-called standards which our experiments have led to. Again, the sample dietaries adopted in our experiments have no special virtue, aside from the general principle they teach that simple foods are quite adequate for the nourishment of the body, and that the amount of nitrogen or proteid they contain was sufficient to meet the demands of the particular individuals consuming it. Broadening intelligence on matters of food composition is called for on all sides, and as this is acquired together with due appreciation of the relative nutritive values of proteid, fat, and carbohydrate, there is placed at our command the power of intelligent discrimination, with the ability to apply the principles set forth in our own way, in harmony with personal likes and dislikes.

To the majority of us, not very familiar with the percentage composition of ordinary food materials, and unaccustomed to the weighing of food in grams, the figures given from time to time may have failed to convey a very definite impression regarding the actual amounts of the various foods made use of. Further, our ideas concerning the bulk of many of the common articles of food necessary to furnish the 60 grams of proteid required daily by a man of 70 kilograms body-weight may be somewhat hazy. The following table, however, will be of service in this direction:

* Fuel value of the quantity needed to furnish the sixty grams of proteid.

The figures in this table are instructive in many ways. First, it is to be noted that the daily proteid requirement of sixty grams can be obtained from one-half pound of lean meat (uncooked), of which the loin steak is a type. Subject to some variations in content of water, an equivalent weight of lean flesh of any variety, lamb, veal, poultry, etc., will furnish approximately the same amount of proteid. With fish, such as halibut steak, and with liver, three-quarters of a pound are required; while with sweetbreads, four-fifths of a pound are needed to furnish the requisite amount of proteid. Of salt codfish, one-half pound will provide the same amount of proteid as an equivalent weight of fresh beef; while with lean smoked bacon the amount rises to seven-eighths of a pound. Among the vegetable products, it is to be observed that dried peas and beans, almonds and pine nuts, are as rich in proteid as the above-mentioned animal foods, essentially the same weights being called for to provide the daily requirement of proteid. The same is true of cheese, the variety designated having such a composition that one-half pound is the equivalent, so far as the content of proteid is concerned, of a like amount of fresh beef. We must not be unmindful of the fact previously mentioned, however, that there are differences in digestibility among these various foodstuffs which tend to lower somewhat the availability of the vegetable products, also of the cheese, thereby necessitating a slight increase in the amount of these foods required to equal the value to the body of lean meat.

Secondly, passing to the other extreme in our list, we find indicated types of foods exceedingly poor in proteid, such as the fruits; notably, bananas, grapes, prunes, apples, etc., also lettuce, and in less degree potatoes. These are the kinds of food that may legitimately attract by their palatability, but do not add materially to our intake of proteid even when consumed in relatively large amounts. Thirdly, we see clearly indicated a radical difference between the animal foods and those of vegetable origin, in that with the former the fuel value of the quantity necessary to furnish the sixty grams of proteid is very small, as compared with a like amount of the average vegetable product. One-half pound of lean meat, for example, with its 60 grams of proteid, has a fuel value of only 308 calories, while two-thirds of a pound of almonds has a fuel value of 2020 calories, and one-half pound of dried peas 827 calories. Naturally, this is mainly a question of the proportion of fat or oil present. With fat meat, as in bacon, the calorific value rises in proportion to increase in the amount of fat, the proteid decreasing in greater or less measure.

The main point to be emphasized in this connection, however, is that a high proteid animal food, like lean meat, eggs, fish, etc., obviously cannot alone serve as an advantageous food for man. We see at once the philosophy of a mixed diet. Let us assume that our average man of 70 kilograms body-weight needs daily 2800 calories. On this assumption, if he were to depend entirely upon lean beef for his sustenance, he would require daily four and a half pounds of such meat, which amount would furnish nine times the quantity of proteid needed by his system. The same would be more or less true of other kindred animal products. On the other hand, certain vegetable foods on our list, such as flaked rice, crackers, and shredded wheat, contain proteid, with carbohydrate and fat, in such proportion that the energy requirement would be met essentially by the same quantity as served to furnish the necessary proteid. Passing to the other extreme among the vegetable products, as in potatoes and bananas, for example, we find fuel value predominating largely over proteid content. The ideal diet, however, is found in a judicious admixture of foodstuffs of both animal and vegetable origin. Wheat bread, reinforced by a little butter or fat bacon to add to its calorific value, shredded wheat with rich cream, crackers with cheese, bread and milk, eggs with bacon, meat with potatoes, etc.; the common, every-day household admixtures, provide combinations which can easily be made to accord with true physiological requirements. The same may be equally true of the more complicated dishes evolved by the high art of modern cookery.

Lastly, our table throws light upon certain questions of household economy. The cost of foods is regulated mainly not by the value of the nutrients contained therein, but by other factors of quite a different nature. Relationship between supply and demand naturally counts here as in other directions, but our demand is liable to be based not upon food values, but rather upon delicacy of flavor, palatability, and other kindred fancies, some real and some imaginary. Ordinary crackers can be purchased for ten cents a pound, but if we desire a little stronger flavor of salt and a special box to hold them, we pay eighteen cents a pound. Rolled very thin and thus made more delicate, they cost twenty-five cents, while sold under a special name and perhaps tied with a blue ribbon they cost thirty-five cents a pound. Their nutritive value per pound is the same in all cases, but we pay something for the increased labor of preparation and a good deal for the added attractiveness to eye and palate. We pay twenty-two cents a pound for round steak, thirty-two cents for loin steak, and seventy-five cents a pound for sweetbreads, the high price of the latter being regulated by the relative scarcity of the article and not by its food value. As our table indicates, the real value of sweetbread as a source of proteid is only a little more than half that of lean beef. Its fuel value, however, is somewhat more than that of beef, but a little fat added to the latter will more than compensate and at a trifling cost. When we can afford it, we pay the increased price for sweetbreads simply because their delicacy and flavor are attractive to us. We should not do it under the mistaken idea that we are indulging in a highly nutritive article of food, for as a matter of fact it is not only less nutritive than a corresponding weight of lean beef, but in addition it possesses certain qualities, in its high purin-content, that are a menace to good health if indulged in too freely.

Where expense must be carefully guarded, or where the condition of the family purse is such that conflicting demands must be intelligently considered in order to insure wise expenditure and the greatest permanent good of the many, it is well to remember that price is no guarantee whatever of real nutritive value. Two quarts of milk will furnish half the daily fuel requirement of our average man and the entire proteid requirement, while its cost is only sixteen cents. Reinforced by a pound loaf of wheat bread, the energy requirement for the day would be fully met, with surplus nitrogen to store up for future needs, and at an additional cost of only ten cents. A mixture in this proportion, however, would not be strictly physiological, since it is wasteful of proteid, but it may serve to illustrate the point. A better illustration is found in an admixture, quite adequate to supply the daily needs of our average man, both for proteid and energy, composed of one-quarter of a pound of lean beef, two-thirds of a pound of bread, and half a pound of butter, and at a total cost not to exceed thirty cents. The contrast of such prices with what is so commonly paid for table delicacies is somewhat striking; it could be made still more so by drawing upon many common vegetable foods, rich alike in proteid and in fuel value, the cost of which is even less than the simple food mixtures just referred to. It is not necessary, however, to enlarge upon this question; it is sufficient to merely emphasize the fact that the exaggerated demand of our present generation for dietetic luxuries is leading us far away from the proverbially simple life of our forefathers, and without adding in any way to the effectiveness of the daily diet. On the contrary, it is in part responsible for the high proteid consumption of the present day, with its attendant evils, and involves a large and unnecessary expenditure without adequate return. The wants of the body for food are far more advantageously met by a simple dietary, moderate in amount and at an expense comparatively slight.

A recent writer,76 in the “British Medical Journal,” a practitioner of medicine in the Highlands of Scotland, has said that these are “facts of common experience in the Highlands of Scotland, and probably among the peasantry of other countries also, where the old beliefs and customs have not too readily given way to the luxuries of civilization. Oatmeal in one form or another is a daily ingredient in the diet of a Highland peasant. The potato also is a staple food, and is consumed in large quantities with salt herring or other fish, and perhaps in some cases salt mutton or pork. Milk and eggs are used by most. The growing consumption of tea, however, and the increasing relish for sweets, candy, pastry, and biscuits, threaten to destroy the old way of living. A typical day’s diet for a crofter or fisherman who still believes in the traditional diet would be somewhat like this:

“I have often been assured by shepherds that they could work all day ‘on the hill’ after a breakfast of oatmeal brose and milk, without fatigue and without feeling hungry, returning in the evening to partake of a dish of broth, potatoes, and salt mutton. In these diets, proteid forms a very small proportion, and yet a hardier race than these shepherds and fishermen cannot be found.” It should be added that “brose” consists of a few handfuls of oatmeal, to which is added boiling water, the mixture being stirred vigorously and placed for a few minutes near the fire. It is then eaten with milk, or better, with cream. In the absence of positive data, it can only be asserted that the above dietary stands for simplicity and frugality. Its proteid-content may be low, but the amount of proteid taken per day by these Highlanders will obviously depend upon the quantity of food consumed. Oatmeal is fairly rich in proteid, and it is quite conceivable that the amount eaten daily may be such as to result in a high proteid exchange.

It will be profitable for us to gain, if possible, a fairly clear idea of the quantities of food requisite for our average man of 70 kilograms body-weight; i. e., the amounts necessary to provide 60 grams of proteid and 2800 calories. With this end in view, we may outline a simple dietary, expressed in terms that will convey a clear impression, showing what may be eaten without overstepping the required limits of proteid or total calories:

The grand totals for the day, with this dietary, amount to 58.07 grams of proteid and 2729 calories. It is of course understood that these figures are to be considered as only approximately correct, but the illustration will suffice, perhaps, to give a clearer understanding of the actual quantities of food involved in a daily ration approaching the requirements for a man of 70 kilograms body-weight. Further, there may be suggested by the figures given for proteid and fuel value of the different quantities of foods, a clearer conception of how much given dietary articles count for in swelling the total values of a day’s intake. Moreover, it is easy to see how the diet can be added to or modified in a given direction. If a little more proteid is desired without changing materially the fuel value of the food a boiled egg can be added to the breakfast, for example. An average-sized egg (of 53 grams) contains 6.9 grams of proteid, while it will increase the fuel value of the food by only 80 calories. Or, if more vegetable proteid is wished for, a soup of split-peas can be introduced, without changing in any degree the calorific value of the diet. Thus, one teacup of split-pea soup (144 grams) contains 8.64 grams of proteid, while the fuel value of this quantity may be only 94 calories. The addition of one banana (160 grams) will increase fuel value 153 calories, but will add only 2.28 grams of proteid. If it is desired to increase fuel value without change in the proteid-content of the food, recourse can always be had to butter, fat of meat, additional oil in salads, or to syrup and sugar.

Such a menu as is roughly outlined, however, has perhaps special value in emphasizing how largely the proteid intake is increased by foods other than meats, and which are not conspicuously rich in proteid matter. All wheat products, for example, while abounding in starch, still show a large proportion of proteid. Thus, shredded wheat biscuit (1 ounce), which is a type of many kindred wheat preparations, from bread and biscuit to the various so-called breakfast foods, yields about 3 grams of proteid per ounce and approximately 100 calories. Even potato, which is conspicuously a carbohydrate food owing to its large content of starch, yields of nitrogen the equivalent of at least three-fourths of a gram of proteid per ounce. If larger volume is desired without much increase in real food value, there are always available green foods, such as lettuce, celery, greens of various sorts, fruits, such as apples, grapes, oranges, etc. Too great reliance on meats as a type of concentrated food, on the other hand, augments largely the intake of proteid, and adds a relatively small amount to the fuel value of the day’s ration.

An ingenious method of indicating food values, which promises to be of service in sanatoria and under other conditions where it is desirable to record or correct the diet of a large number of persons, has been devised recently by Professor Fisher.77 The method aims to save labor, and is likewise designed to visualize the magnitude and proportions of the diet. The food is measured by calories instead of by weight, a “standard portion” of 100 large calories being the unit made use of. In carrying out the method, foods are served at table in “standard portions,” or multiples thereof. In the words of Fisher, the amount of milk served, for example, “instead of being a whole number of ounces, should be 4.9 ounces—the amount that contains 100 calories. This ‘standard portion’ constitutes about two-thirds of an ordinary glass of milk. Of the 100 calories which it contains 19 will be in the form of proteid, 52 in fat, and 29 in carbohydrate.” In the carrying out of this plan, it is evident that the weight of any food yielding 100 calories becomes a measure of the degree of concentration. From the standpoint of fuel value, olive oil is probably one of the most concentrated of foods, approximately one-third of an ounce containing 100 calories. The following table, taken from Fisher’s description of his method, will serve to show the amounts of several foods constituting a “standard portion,” and also the number of calories in the form of proteid, fat, and carbohydrate:

Obviously, to make use of the “calories per cent” method a table such as the above, covering all common foodstuffs and showing the weight of each food constituting a standard portion, together with the calories of proteid, fat, and carbohydrate in this portion, is necessary. The chief advantage of the method, however, is that it lends itself readily to geometrical representation and affords an easy means of determining the constituents of combinations of different foods by use of a simple mechanism, for a description of which reference must be made to the original paper.

Any attempt to follow a daily routine which accords with the true needs of the body leads necessarily toward foods derived from the plant kingdom, with the adoption of simple dietary habits, and with greater freedom from the exciting influence of the richer animal foods. There is, however, virtue in a simple dietary that appeals and satisfies, and in so doing testifies to the completeness with which it meets the physiological requirements of the body. A physician,78 writing in the “British Medical Journal,” says: “I determined to give the minimum-of-proteid diet a fair trial in my own case. The result was that I was relieved of a life-long tendency to acid dyspepsia and occasional sick headache; my fitness for work, my appetite and relish for food, were increased, without any diminution, but rather a slight increase, in my weight. My practice extends over a wide area of rough mountainous country involving long journeys on cycle, on foot, driving, and in open boats, in fair and foul weather. The muscular exertion and endurance necessary for the work would seem to require a large proportion of proteid and a generous diet altogether, but since I began to experiment I have suffered less than formerly from fatigue, and seem to eat in all a smaller quantity of food. My diet consists of: