Average Intake.

Dr. Arthur L. Dean, Instructor in Plant Physiology in the Sheffield Scientific School, twenty-five years of age, and weighing 64 kilos, likewise became a subject of study in this investigation. He is a man of strong physique, and as an undergraduate student at Harvard University trained for various athletic events. He began on the experiment October 13, 1903, and continued until April 3, 1904. From October 13th to October 27 he followed his usual dietary habits, simply reducing in some measure the amount of food consumed. During this period of fifteen days, the average excretion of nitrogen per day through the kidneys was about 12 grams. On the 28th of October he began to reduce in still greater measure the amount of proteid food eaten, and gradually diminished the extent of his proteid metabolism, although not to the same degree as the preceding subjects. He had full freedom of choice in the character and quantity of his diet, but his food was characterized by a predominance of vegetable matter, with an almost complete exclusion of meat.

For a period of nearly six months, or more exactly, from October 28 to April 3, the average daily output of nitrogen through the kidneys amounted to 8.99 grams, while the average daily output of uric acid was 0.386 gram. This daily excretion of 8.99 grams of nitrogen implies a metabolism of 56.18 grams of proteid. This, to be sure, means a reduction in proteid metabolism of about 50 per cent, as compared with the Voit and other standards, but does not show an economy equal to that practised by the preceding subjects. It is to be noted, however, in Dr. Dean’s case, that the body-weight did not show at any time in the experiment a tendency to diminish. In fact, all through the experiment his body-weight was a little higher than at the beginning.

DEAN.

On February 9, a nitrogen balance was attempted, when for a period of six days a careful comparison of intake and output of nitrogen was made. The results show that while during this period of six days 52.999 grams of nitrogen were ingested, there was an output through the urine and fæces of 61.13 grams of nitrogen, thus indicating a minus balance for this period of 1.355 grams of nitrogen per day. The average daily intake of nitrogen was 8.83 grams. The average daily output of nitrogen through the kidneys was 8.77 grams, being 0.22 gram less than the average daily excretion through the kidneys for the six months’ period. The fuel value of the food for this period averaged 2529 calories per day. The nitrogen balance, however, is so strikingly a minus balance that we are forced to conclude the above quantities of food were not quite sufficient to meet the needs of the body under the then existing conditions. Still, the fact that the body-weight during the entire period of six months showed no tendency downward implies that during this longer period the body must have been essentially in nitrogen equilibrium, under conditions whereby there was a metabolism of only 56 grams of proteid per day. As before stated, this means a physiological economy, as contrasted with existing standards, of about 50 per cent in proteid food. So far as was to be seen, the bodily strength and vigor of the subject, like his body-weight, were fully maintained under the restricted diet, but, for some reason, he did not apparently take as kindly to a reduction of proteid food, and did not accomplish so great a lowering in the rate of proteid metabolism.

Following are the data of the balance experiment:

Tuesday, February 9, 1904.

Breakfast.—Coffee 210 grams, bread 38.5 grams, oatmeal 127 grams, cream 92 grams, sugar 20 grams.

Lunch.—Bread 63.5 grams, butter 12.5 grams, potato 155 grams, consommé 150 grams, stewed tomato 109 grams, coffee 210 grams, sugar 20 grams, pudding 85 grams.

Dinner.—Roast beef 17.5 grams, potato 177 grams, bread 39.1 grams, butter 12 grams, string beans 110 grams, apple pie 237.6 grams.

Wednesday, February 10, 1904.

Breakfast.—Coffee 210 grams, bread 31.8 grams, cream 50 grams, sugar 40 grams, oatmeal 155 grams.

Lunch.—Bread 77 grams, butter 14.5 grams, apple fritters 193.5 grams, coffee 210 grams, sugar 20 grams.

Dinner.—Bread 82 grams, butter 20 grams, cranberries 150 grams, baked beans 150 grams, coffee 210 grams, sugar 32 grams.

Thursday, February 11, 1904.

Breakfast.—Bread 49 grams, oatmeal 185.7 grams, cream 64 grams, coffee 210 grams, sugar 35 grams.

Lunch.—Bread 111.8 grams, butter 40.5 grams, sweet potato 287 grams, peach preserve 109.3 grams.

Dinner.—Tomato purée 99 grams, bread 94.5 grams, butter 21.5 grams, beans 138 grams, lemon pie 155 grams, coffee 210 grams, sugar 21 grams.

Friday, February 12, 1904.

Breakfast.—Oatmeal 192.3 grams, cream 75.5 grams, bread 41.6 grams, coffee 210 grams, sugar 20 grams.

Lunch.—Bread 64.1 grams, butter 14 grams, fish cakes 60 grams, potato 200 grams, custard 107.3 grams.

Dinner.—Bread 60 grams, butter 15 grams, lima beans 100 grams, potato 150 grams, apple dumpling 259 grams.

Saturday, February 13, 1904.

Breakfast.—Oatmeal 150 grams, cream 42 grams, sugar 31 grams, bread 31 grams, coffee 210 grams.

Lunch.—Bread 36 grams, sweet potato 222 grams, butter 17 grams, quince preserve 81.5 grams, apple turnover 154.5 grains.

Dinner.—Potato 175 grams, bread 62 grams, butter 15 grams, peas 100 grams, apple pie 177 grams, coffee 210 grams, sugar 21 grams.

Sunday, February 14, 1904.

Breakfast.—Quaker oats 150 grams, bread 42.5 grams, coffee 210 grams, sugar 31 grams, banana 88.2 grams, cream 87.6 grams.

Lunch.—Bread 87.3 grams, butter 28.7 grams, potato 210 grams, apple sauce 116.5 grams.

Dinner.—Bread 51.5 grams, butter 12.2 grams, sugar 21 grams, potato 150 grams, succotash 100 grams, chocolate cake 122.5 grams, vanilla ice 110.7 grams.

NITROGEN BALANCE.—Dean.

Average Intake.

Mr. George M. Beers, Clerk in the Treasurer’s office of the Sheffield Scientific School, became a subject of study in January, 1903. Mr. Beers was thirty-eight years of age, and had always enjoyed fairly good health, although of somewhat frail physique. His occupation has always been indoor work as accountant, etc. His body-weight was 61 kilos.

Mr. Beers came to the writer for advice as to possible ways of improving his general health, and when it was learned that he was in the habit of eating large amounts of meat, the suggestion was made to him that it might be wise to ascertain the effect of a diminished quantity of proteid food, and as a result of this advice Mr. Beers began to cut down the amount of meat consumed daily. The effect of this abstention from meat was so noticeable that voluntarily all meat was withdrawn from his diet. With this change in dietary habits there came about a loss of body-weight, which, however, was soon regained.

Commencing with May 14, 1903, the amount of nitrogen excreted from the kidneys was determined from time to time, but not each day, since it was very soon found that Mr. Beers showed great regularity in his dietary habits, and a corresponding regularity in the composition of the output. This regularity was due in large measure to the fact that the subject became, for the time at least, practically a vegetarian. The beneficial effects noted in his own experience with abstention from meat led to his voluntarily excluding it from his daily diet, so that from January, 1903, to June, 1904, the subject practically tasted meat, fish, or eggs on only four occasions, namely, the 26th day of November, 1903, May 19, 20, and 21, 1904. With this limitation to a vegetable diet and with regular methods of living, the nitrogenous waste material was found to be constant within very narrow limits. Emphasis, however, should be laid upon the fact that there was no prescription of diet, but perfect freedom of choice, although this choice was limited wholly to vegetable and cereal foods.

The accompanying tables give the output of nitrogen, uric acid, etc., through the kidneys for various dates between May 14, 1903, and June 15, 1904. Scrutiny of these tables shows that the average daily output of nitrogen, so far as the data show, amounted to 8.58 grams. This indicates an average daily metabolism of 53.62 grams of proteid material.

Likewise noticeable is the perfectly steady body-weight throughout this whole period of time, while the low level of 8.5 grams of metabolized nitrogen testifies to an economy in the use of proteid food, which indicates that in this subject at least the needs of the body for proteid food could easily be met by an amount equal to about one-half that called for by the Voit and similar standard dietaries.

BEERS.