Thursday, March 24, 1904.

Breakfast, 7.45 A. M.—Coffee 100 grams, cream 25 grams, sugar 8 grams.

Lunch, 1.30 P. M.—Shredded wheat biscuit 29 grams, cream 118 grams, wheat gems 60 grams, butter 8 grams, tea 100 grams, sugar 7 grams, apple pie 102 grams.

Dinner, 6.30 P. M.—Milk-celery soup 140 grams, bread 15 grams, butter 1 gram, lettuce sandwiches 62 grams, tea 100 grams, sugar 10 grams, lemon pie 109 grams.

Friday, March 25, 1904.

Breakfast, 7.45 A. M.—Coffee 100 grams, cream 25 grams, sugar 9 grams.

Lunch, 1.30 P. M.—Halibut with egg sauce 108 grams, mashed potato 89 grams, biscuit 48 grams, butter 10 grams, chocolate-cream cake 90 grams, tea 100 grams, sugar 9 grams.

Dinner, 6.30 P. M.—Milk-celery soup 121 grams, lettuce sandwiches 61 grams, creamed potato 65 grams, lettuce-apple-celery salad 74 grams, coffee 70 grams, sugar 10 grams.

NITROGEN BALANCE.—Chittenden.

Average Intake.

Examination of the results shown in the foregoing balance makes it quite clear that the body was essentially in nitrogenous equilibrium. Indeed, there was a slight plus balance, showing that even with the small intake of proteid food the body was storing up nitrogen at the rate of 0.16 gram per day. The average daily intake of nitrogen for the six days’ period was 6.40 grams, equal to 40.0 grams of proteid or albuminous food. The average daily output of nitrogen through the urine and fæces was 6.24 grams. The average daily output of nitrogen through the urine for the six days’ period was 5.44 grams, corresponding to the metabolism of 34 grams of proteid material. When these figures are contrasted with the usually accepted standards of proteid requirement for the healthy man, they are certainly somewhat impressive, especially when it is remembered that the body at that date had been in essentially this same condition for at least six months, and probably for an entire year. The Voit standard of 118 grams of proteid, with an equivalent of at least 18 grams of nitrogen and calling for the metabolism of 105 grams of proteid, or 16.5 grams of nitrogen per day, makes clear how great a physiological economy had been accomplished. In other words, the consumption of proteid food was reduced to at least one-third the daily amount generally considered as representing the average requirement of the healthy man, and this with maintenance of body-weight at practically a constant point for the preceding ten months, and, so far as the writer can observe, with no loss of vigor, capacity for mental and physical work, or endurance. Indeed, the writer is disposed to maintain that he has done more work and led a more active life in every way during the period of this experiment, and with greater comfort and less fatigue than usual. His health has certainly been of the best during this period.

In this connection it may be well to call attention to the completeness of the utilization of the daily food in this six days’ experiment, as shown by the small amount of refuse discharged per rectum, indicating as it does the high efficiency of the digestive processes and of the processes of absorption. The refuse matter for the entire period of six days amounted when dry to only 74 grams, and when it is remembered how large a proportion of this refuse must of necessity be composed of the cast-off secretions from the body, it will be seen how thorough must have been the utilization of the food by the system. The loss of nitrogen to the body per day through the fæces amounted to only 0.79 gram, and this on a mixed diet containing considerable matter not especially concentrated, and on some days with noticeable amounts of food, such as salads, not particularly digestible.

Finally, emphasis should be laid upon the fact that this economy of proteid food, this establishment of nitrogen equilibrium on a low proteid intake, was accomplished without increase in the daily intake of non-nitrogenous foods. In fact, the amount of fats and carbohydrates was likewise greatly reduced, far below the minimal standard of 3000 calories as representing the potential energy or fuel value of the daily diet. Indeed, during the balance period of six days just described the average fuel value of the food per day was only a little over 1600 calories.

As the experiment continued and the record for the months of April and May was obtained, it became evident from the nitrogen results that the rate of proteid katabolism was being still more reduced. A second balance experiment was therefore tried with a view to seeing if the body was still in nitrogen equilibrium, and also to ascertain whether the fuel value of the food still showed the same low calorific power. For a period of five days, June 23 to 27, the intake of food and the entire output were carefully compared, with the results shown in the accompanying tables.

Thursday, June 23, 1904.

Breakfast.—Coffee 123 grams, cream 50 grams, sugar 11 grams.

Lunch.—Omelette 50 grams, French fried potatoes 70 grams, bacon 10 grams, wheat gems 43 grams, butter 9 grams, strawberries 125 grams, sugar 20 grams, cream cake 59 grams.

Dinner.—Beefsteak 34 grams, peas 60 grams, creamed potato 97 grams, bread 26 grams, butter 17 grams, lettuce-orange salad 153 grams, crackers 43 grams, cream cheese 15 grams, coffee 53 grams, sugar 12 grams.

Friday, June 24, 1904.

Breakfast.—Coffee 96 grams, sugar 8 grams, milk 32 grams.

Lunch.—Creamed codfish 89 grams, baked potato 95 grams, butter 10 grams, hominy gems 58 grams, strawberries 86 grams, sugar 26 grams, ginger snaps 47 grams.

Dinner.—Cold tongue 14 grams, fried potato 48 grams, peas 60 grams, wheat gems 30 grams, butter 11 grams, lettuce-orange salad with mayonnaise dressing 155 grams, crackers 22 grams, cream cheese 14 grams, ginger snaps 22 grams, coffee 58 grams, sugar 10 grams.

Saturday, June 25, 1904.

Breakfast.—Coffee 101 grams, milk 36 grams, sugar 13 grams.

Lunch.—Omelette 50 grams, bacon 9 grams, French fried potato 23 grams, biscuit 29 grams, butter 8 grams, cream cheese 17 grams, iced tea 150 grams, sugar 15 grams, ginger snaps 42 grams.

Dinner.—Wheat popovers 57 grams, butter 10 grams, lettuce-orange salad with mayonnaise dressing 147 grams, cream cheese 21 grams, crackers 22 grams, cottage pudding 82 grams, coffee 48 grams, sugar 11 grams.

Sunday, June 26, 1904.

Breakfast.—Coffee 122 grams, cream 31 grams, sugar 8 grams.

Dinner.—Roast lamb 50 grams, baked potato 52 grams, peas 64 grams, biscuit 32 grams, butter 12 grams, lettuce salad 43 grams, cream cheese 21 grams, toasted crackers 23 grams, blanc mange 164 grams.

Supper.—Iced tea 225 grams, sugar 29 grams, lettuce sandwich 51 grams, strawberries 130 grams, sugar 22 grams, cream 40 grams, sponge cake 31 grams.

Monday, June 27, 1904.

Breakfast.—Coffee 112 grams, cream 22 grams, sugar 10 grams.

Lunch.—Roast lamb 9 grams, baked potato 90 grams, wheat gems 47 grams, butter 12 grams, sugar 25 grams, iced tea 250 grams, vanilla éclair 47 grams.

Dinner.—Lamb chop 32 grams, asparagus 49 grams, butter 17 grams, creamed potato 107 grams, bread 35 grams, lettuce-orange salad with mayonnaise dressing 150 grams, cream cheese 12 grams, crackers 21 grams, coffee 63 grams, sugar 9 grams.

NITROGEN BALANCE.—Chittenden.

Average Intake.

Examination of these figures makes quite clear that the body was still in nitrogen equilibrium, or essentially so, the minus balance being so small as to have little significance. The body-weight was still stationary, and yet during this balance period the average daily intake of nitrogen was only 5.86 grams, corresponding to 36.62 grams of proteid or albuminous food. Further, the average daily fuel value of the food was only 1549 calories, a trifle less than in the preceding period. The average daily output of nitrogen through the urine for this period was 4.92 grams, corresponding to the metabolism of 30.7 grams of proteid food. Hence, the results of this period confirm those of the preceding period and make it quite clear that this subject, with a body-weight of 57.5 kilos, can be maintained in body equilibrium, and in nitrogen equilibrium, on a daily diet containing only 5.8 grams of nitrogen and with a fuel value of about 1600 calories. Under these conditions, as in the last balance period, the daily amount of nitrogen metabolized was very small, averaging only 4.92 grams. Comparison of this figure with the accepted standard of 16 grams of nitrogen makes quite clear the extent of the physiological economy which is attainable by the body, and emphasizes also the extent of the unnecessary and worse than useless labor put upon the body by the prevalent dietetic habits of the majority of mankind.

It is of course understood that the low fuel value which sufficed to keep the writer in body equilibrium would not meet the requirements of a more active life, with greater physical labor. The writer has led a very busy life during the year of this experiment, but it has been mental activity rather than physical, although doubtless he has exercised as much as the ordinary professional worker not accustomed to athletic sports. The results of the experiment, however, make it quite clear that a man of the above body-weight, even though he lead a very active life—not involving great physical labor—can maintain his body in equilibrium indefinitely with an intake of 36 to 40 grams of proteid or albuminous food, and with a total fuel value of about 1600 calories. Further, it is to be understood that there is no special form of diet involved in the accomplishment of such a result. Scrutiny of the daily diet, tabulated in the two balance periods, will show the character of the food made use of. Personal likes and dislikes must naturally enter into the choice of any diet, and freedom of choice, freedom to follow the dictates of one’s appetite, with such regulation as comes from the use of reason and intelligence, are all that is necessary to secure the desired end. Physiological economy in nutrition is easily attainable and does not involve the adoption of vegetarianism. It does mean, however, temperance and simplicity in diet, coupled with intelligent regulation, which, however, soon becomes a habit and eventually leads to a moderation in diet which fully satisfies all the cravings of appetite as completely as it suffices to maintain the body in equilibrium and in a general condition of health and vigor.

Taking the data recorded above, we may now calculate the nitrogen requirement of the body per kilo of body-weight. With the body-weight placed at 57 kilos and with an average daily elimination of nitrogen for nearly nine months of 5.699 grams, or practically 5.7 grams, it is evident that the nitrogen metabolized per kilo of body-weight in the present instance was exactly 0.1 gram. If we take the lower figure of 5.40 grams of nitrogen, the average daily excretion from April 13 to June 27, we find the nitrogen requirement to be 0.0947 gram per kilo of body-weight. Translating these figures into terms of proteid or albuminous matter, they mean the utilization or metabolism of 0.625 gram of proteid matter daily per kilo of body-weight, under the conditions of life, activity, and general food consumption prevailing throughout this period of nearly nine months with this particular individual.

Whether we are justified in saying that this figure represents the minimal proteid requirement of this particular individual is perhaps questionable, since the proteid or nitrogen requirement will of necessity vary somewhat with the amount of non-nitrogenous food consumed. Doubtless, the nitrogen metabolism could be reduced still lower by increasing the intake of non-nitrogenous food, but under the above conditions of life, following a plan of living both congenial and satisfactory, one that fully sufficed to keep the body in equilibrium and with the practice of a general physiological economy, we may say that the metabolism of 0.1 gram of nitrogen per kilo of body-weight was quite sufficient to meet all the requirements of the body. Health, strength, mental and physical vigor have been maintained unimpaired, and there is a growing conviction that in many ways there is a distinct improvement in both the physical and mental condition. Greater freedom from fatigue, greater aptitude for work, greater freedom from minor ailments, have gradually become associated in the writer’s mind with this lowered proteid metabolism and general condition of physiological economy. The writer, however, is fully alive to the necessity of caution in the acceptance of one’s feelings as a measure of physical or mental condition, but he has been keenly watchful for any and every sign or symptom during the course of these experiments, and is now strongly of the opinion that there is much good to be gained in the adoption of dietetic habits that accord more closely with the true physiological needs of the body. If a man of 57 kilos body-weight can maintain a condition of equilibrium, with continuance of health, strength, and vigor (to say nothing of possible improvement), with a daily consumption of say 40 grams of proteid food and sufficient non-nitrogenous food to yield 2000 calories, why should he load up his system each day with three times this amount of proteid food, with enough more fat and carbohydrate to yield 3000 plus calories?

Finally, the writer in summing up his own experience is inclined to say that while he entered upon this experiment simply with a view to studying the question from a purely scientific and physiological standpoint, he has become so deeply impressed with the great gain to the body by this practice of physiological economy, and his system has become so accustomed to the new level of nutrition that there is no desire to return to the more liberal dietetic habits of former years.

Obviously, it is not wise nor safe to draw too broad deductions from a single individual, nor from a single experiment even though it extends over a long period of time; consequently, we may turn our attention to other individuals with presumably different personality and different habits of life. The writer’s colleague, Dr. Lafayette B. Mendel, Professor of Physiological Chemistry in the Sheffield Scientific School, kindly volunteered to become a subject of experiment. With a body-weight of 76 kilos, 32 years of age, and of strong physique, he commenced to modify his diet about the middle of October, 1903, diminishing gradually the amount of proteid food with the results shown in the following tables, where are given, as in the preceding experiment, the amounts of nitrogen in the urine, as a measure of the quantity of proteid metabolized, uric acid, and other factors of interest in this connection.

The collection of data commenced on October 26, 1903. During some weeks the urine of each day was not analyzed by itself, but an aliquot part was taken from the 24 hours’ quantity, and at the end of a week the determinations were made on the mixture, thereby giving the average daily composition for the period. With Dr. Mendel, as in the writer’s case, there was no prescribing of food, but perfect freedom of choice. The appetite was satisfied each day, but with a gradual diminution of proteid food, especially of meat. Dr. Mendel appeared to accomplish the desired end best by keeping up a liberal allowance of non-nitrogenous food, and the total potential energy of the daily diet was not so greatly diminished as in the writer’s case. In other words, he appeared to need more food, but succeeded without great effort in reducing the proteid intake to nearly as low a level as in the preceding experiment. For the period of three months from January 4 to April 3, 1904, the average daily excretion of nitrogen amounted to 6.46 grams, which means the metabolism of 40.37 grams of proteid or albuminous food per day for this quarter of the year.

MENDEL.