Chapter I: Experiments with Professional Men (4)

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.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Coffee 210.0 × 0.10 = 0.210 grams.
Bread 38.5 + 63.5 + 39.1 = 141.1 × 1.36 = 1.918
Oatmeal 127.0 × 0.64 = 0.812
Cream 92.0 × 0.40 = 0.368
Butter 12.5 + 12 = 24.5 × 0.088 = 0.021
Potato 155.0 × 0.28 = 0.434
Consommé 150.0 × 0.38 = 0.570
Tomato 109.0 × 0.19 = 0.207
Sugar 20 + 20 = 40.0 × 0.00 = 0.000
Pudding 85.0 × 0.69 = 0.586
Roast beef 17.5 × 2.64 = 0.462
Potato 177.0 × 0.36 = 0.637
String beans 110.0 × 0.26 = 0.286
Apple pie 237.6 × 0.49 = 1.164
Coffee 210.0 × 0.099 = 0.208
------
Total nitrogen in food 7.883 grams.
Total nitrogen in urine 8.640

Fuel value of the food 2576 calories.

_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.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Coffee 210.0 × 0.12 = 0.252 grams.
Bread 31.8 + 77 + 82 = 190.8 × 1.65 = 3.148
Cream 50.0 × 0.47 = 0.235
Sugar 40 + 20 + 32 = 92.0 × 0.00 = 0.000
Oatmeal 155.0 × 0.60 = 0.930
Butter 14.5 + 20 = 34.5 × 0.088 = 0.030
Fritters 193.5 × 0.45 = 0.870
Coffee 210.0 × 0.11 = 0.231
Cranberries 150.0 × 0.04 = 0.060
Baked beans 150.0 × 1.40 = 2.100
Coffee 210.0 × 0.11 = 0.231
------
Total nitrogen in food 8.087 grams.
Total nitrogen in urine 8.290

Fuel value of the food 2145 calories.

_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.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Bread 49 + 111.8 + 94.5 = 255.3 × 1.75 = 4.467 grams.
Oatmeal 185.7 × 0.40 = 0.742
Cream 64.0 × 0.49 = 0.313
Coffee 210.0 × 0.096 = 0.201
Sugar 35 + 21 = 56.0 × 0.00 = 0.000
Butter 40.5 + 21.5 = 62.0 × 0.088 = 0.054
Sweet potato 287.0 × 0.31 = 0.889
Peach preserve 109.3 × 0.09 = 0.098
Tomato purée 99.0 × 0.33 = 0.326
Beans 138.0 × 1.30 = 1.794
Lemon pie 155.0 × 0.61 = 0.945
Coffee 210.0 × 0.13 = 0.273
------
Total nitrogen in food 10.102 grams.
Total nitrogen in urine 8.550

Fuel value of the food 2854 calories.

_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.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 192.3 × 0.52 = 0.999 grams.
Cream 75.5 × 0.50 = 0.377
Bread 41.6 + 64.1 + 60 = 165.7 × 1.71 = 2.833
Coffee 210.0 × 0.11 = 0.231
Sugar 20.0 × 0.00 = 0.000
Butter 14 + 15 = 29.0 × 0.088 = 0.025
Fish cakes 60.0 × 1.57 = 0.942
Potato 200.0 × 0.41 = 0.820
Custard 107.3 × 0.83 = 0.890
Lima beans 100.0 × 0.90 = 0.900
Potato 150.0 × 0.37 = 0.555
Apple dumpling 259.0 × 0.72 = 1.864
------
Total nitrogen in food 10.436 grams.
Total nitrogen in urine 9.930

Fuel value of the food 2363 calories.

_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.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 150.0 × 0.43 = 0.645 grams.
Cream 42.0 × 0.50 = 0.210
Sugar 31 + 21 = 52.0 × 0.00 = 0.000
Bread 31 + 36 + 62 = 129.0 × 1.64 = 2.115
Coffee 210.0 × 0.11 = 0.231
Sweet potato 222.0 × 0.37 = 0.821
Butter 17 + 15 = 32.0 × 0.088 = 0.028
Quince preserve 81.5 × 0.047 = 0.038
Apple turnover 154.5 × 0.96 = 1.483
Potato 175.0 × 0.37 = 0.647
Peas 100.0 × 0.96 = 0.960
Apple pie 177.0 × 0.43 = 0.761
Coffee 210.0 × 0.11 = 0.231
------
Total nitrogen in food 8.170 grams.
Total nitrogen in urine 8.870

Fuel value of the food 2606 calories.

_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.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Quaker oats 150.0 × 0.46 = 0.690 grams.
Bread 42.5 + 87.3 + 51.5 = 181.3 × 1.75 = 3.172
Coffee 210.0 × 0.11 = 0.231
Sugar 31 + 21 = 52.0 × 0.00 = 0.000
Banana 88.2 × 0.20 = 0.176
Cream 87.6 × 0.50 = 0.438
Butter 28.7 + 12.2 = 40.9 × 0.088 = 0.035
Potato 210.0 × 0.41 = 0.861
Apple sauce 116.5 × 0.029 = 0.033
Potato 150.0 × 0.37 = 0.555
Succotash 100.0 × 0.57 = 0.570
Chocolate cake 122.5 × 0.75 = 0.918
Vanilla ice 110.7 × 0.58 = 0.642
------
Total nitrogen in food 8.321 grams.
Total nitrogen in urine 8.330

Fuel value of the food 2635 calories.

NITROGEN BALANCE.—_Dean._

Nitrogen Output.
Taken in. Nitrogen in Urine. Weight of Fæces (dry).

Feb. 9 7.883 grams. 8.64 grams.
10 8.087 8.29
11 10.102 8.55 18 grams.
12 10.436 9.93 18
13 8.170 8.87 80
14 8.321 8.33 58
------ ------ ------
174 grams contain 4.90% N.
52.999 52.61 + 8.52 grams nitrogen.
------ ----------------------
52.999 grams nitrogen. 61.13 grams nitrogen.

Nitrogen balance for six days = -8.131 grams.
Nitrogen balance per day = -1.355 grams.

Average Intake.

Calories per day 2529.
Nitrogen per day 8.83 grams.

* * * * *

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.

+-----------+-------+--------------------------------------------------+
| | | |
| | | Urine. |
| | | |
| Date. | Body- +-------+------+-----------+-----------+-----------+
| |weight.|Volume.| Sp. | Nitrogen. | Uric Acid.| P₂O₅. |
| | | 24 | Gr. | | | |
| | |hours. | | | | |
+-----------+-------+-------+------+-----------+-----------+-----------+
| 1904 | kilos | c.c. | | grams | gram | grams |
| | | | | | | |
| May 14 | 61.1 | 940 | 1020 | 8.23 | 0.330 | 1.82 |
| Oct. 8 | | 920 | 1014 | 6.40 | 0.374 | 1.47 |
| 13 | 61.1 | 740 | 1026 | 8.74 | 0.375 | 1.61 |
| 14 | | 780 | 1024 | 8.37 | | |
| 15 | | 970 | 1018 | 8.90 | 0.374 | 1.04 |
| 16 | | 1365 | 1014 | 9.09 | | |
| 17 | | 1295 | 1013 | 8.86 | | |
| 18 | | 1400 | 1013 | 7.56 | 0.347 | 1.57 |
| 20 | 61.1 | 1304 | 1014 | 8.14 | 0.328 | 1.44 |
| 21 | | 1510 | 1012 | 7.97 | | |
| 22 | | 1450 | 1012 | 8.26 | 0.338 | 1.95 |
| 23 | | 1130 | 1013 | 7.86 | | |
| 24 | | 1060 | 1019 | 8.46 | | |
| 25 | | 1275 | 1015 | 8.25 | 0.375 | 1.74 |
| 26 | | 1390 | 1014 | 7.34 | | |
| 27 | 61.4 | 1000 | 1020 | 7.50 | 0.344 | 1.38 |
| Nov. 21 | 61.4 | 670 | 1025 | 8.72 | | |
| 22 | | 925 | 1017 | 8.21 | 0.335 | 1.28 |
| 23 | | 585 | 1027 | 8.36 | | |
| 24 | | 885 | 1023 | 8.02 | 0.354 | |
| 25 | | 800 | 1026 | 7.92 | | |
| 26 | | 1095 | 1020 | 10.77* | 0.364 | 1.53 |
| Jan. 5 | 61.4 | 1110 | 1018 | 8.99 | 0.324 | |
| 7 | | 650 | 1024 | 8.15 | 0.278 | 1.29 |
| 8 | | 710 | 1020 | 7.88 | | |
| 9 | | 910 | 1023 | 8.73 | | |
| 10 | | 890 | 1020 | 8.01 | 0.327 | 1.21 |
| 11 | | 875 | 1017 | 7.51 | | |
| 12 | | 480 | 1029 | 6.77 | | |
| 13 | | 580 | 1023 | 8.00 | 0.398 | |
| 14 | | 765 | 1022 | 8.35 | | |
| 15 | | 1360 | 1017 | 9.22 | | |
| 16 | 61.4 | 990 | 1020 | 8.79 | | |
| 17 | | 835 | 1024 | 8.47 | 0.354 | |
| 18 | | 780 | 1020 | 8.05 | | |
| 19 | | 790 | 1022 | 8.10 | 0.382 | |
| Feb. 9 | | 860 | 1023 | 8.46 | 0.355 | |
| 10 | 61.4 | 850 | 1024 | 8.57 | 0.226 | |
| 11 | 61.4 | 750 | 1022 | 8.55 | 0.352 | |
| 12 | 61.4 | 595 | 1026 | 8.46 | 0.368 | |
| 13 | 61.4 | 640 | 1027 | 8.75 | 0.425 | |
| 14 | 60.8 | 730 | 1025 | 8.28 | 0.353 | |
| Apr. 18 | 61.5 | 610 | 1025 | 7.69 |⎫ | |
| 19 | 61.5 | 870 | 1020 | 9.87 |⎪ | |
| 20 | 61.5 | 985 | 1019 | 8.87 |⎪ | |
| 21 | 61.5 | 795 | 1024 | 8.25 |⎬ 0.365 | |
| 22 | 61.5 | 1090 | 1019 | 9.02 |⎪ daily | |
| 23 | 61.5 | 970 | 1022 | 8.44 |⎪ average | |
| 24 | 61.5 | 810 | 1021 | 7.30 |⎭ | |
| 25 | 61.5 | 850 | 1018 | 6.94 |⎫ | |
| 26 | 61.5 | 620 | 1024 | 7.11 |⎪ | |
| 28 | | 450 | 1027 | 8.58 |⎬ 0.691 | |
| 29 | | 650 | 1025 | 9.52 |⎪ | |
| 30 | | 1260 | 1018 | 10.20 |⎪ | |
| May 1 | | 1060 | 1017 | 8.71 |⎭ | |
| 2 | | 610 | 1025 | 8.16 | | |
| 3 | | 650 | 1022 | 8.70 | | |
| 4 | 61.5 | 870 | 1019 | 8.51 | | |
| 5 | 61.3 | 610 | 1025 | 8.31 | | |
| 6 | 61.3 | 655 | 1026 | 8.72 |⎫ | |
| 7 | | 680 | 1025 | 8.53 |⎪ | |
| 8 | 60.8 | 490 | 1026 | 7.00 |⎪ | |
| 9 | 61.3 | 550 | 1026 | 7.59 |⎬ 0.356 | |
| 10 | | 705 | 1025 | 7.78 |⎪ | |
| 11 | | 730 | 1025 | 8.28 |⎪ | |
| 12 | | 800 | 1025 | 9.36 |⎭ | |
| 16 | | 715 | 1022 | 7.29 | | |
| 17 | | 990 | 1018 | 6.95 | | |
| 18 | | 715 | 1026 | 7.81 | | |
| 19 | | 845 | 1926 | 10.45† | | |
| 20 | 61.5 | 1170 | 1020 | 11.02† | | |
| 21 | 61.2 | 795 | 1025 | 10.02† | | |
| 22 | | 835 | 1020 | 8.42 | | |
| 23 | | 695 | 1025 | 9.42 | | |
| 24 | | 660 | 1025 | 9.82 | | |
| 25 | | 700 | 1025 | 9.91 |⎫ | |
| 26 | | 620 | 1026 | 8.59 |⎪ | |
| 27 | | 665 | 1026 | 9.53 |⎬ 0.434 | |
| 28 | 61.2 | 960 | 1021 | 10.31 |⎪ | |
| 29 | | 790 | 1023 | 9.24 |⎭ | |
| 31 | | 930 | 1025 | 10.44 | | |
| June 1 | | 855 | 1018 | 8.76 | | |
| 2 | | 850 | 1023 | 8.01 | | |
| 3 | | 860 | 1020 | 9.24 | | |
| 4 | 61.4 | 1145 | 1021 | 10.17 | | |
| 5 | | 590 | 1024 | 7.47 | | |
| 6 | | 510 | 1029 | 7.53 | | |
| 7 | | 620 | 1027 | 8.26 | | |
| 8 | | 985 | 1020 | 8.45 | | |
| 9 | | 1220 | 1020 | 8.49 | | |
| 10 | | 1220 | 1017 | 8.28 | | |
| 11 | | 1710 | 1013 | 8.82 | | |
| 12 | | 925 | 1017 | 7.11 | | |
| 13 | | 920 | 1020 | 8.01 | | |
| 14 | | 1090 | 1015 | 8.64 | | |
| 15 | 61.5 | 915 | 1022 | 8.68 | | |
+-----------+-------+-------+------+-----------+-----------+-----------+
|Daily average | 880 | 1021 | 8.58 | 0.365 | 1.49 |
+-------------------+-------+------+-----------+-----------+-----------+

[*] Turkey eaten on this day.

[†] On these three days, meat, fish, and eggs were eaten.

On February 9, a nitrogen balance was attempted covering a period of six days, in which there was an exact comparison of the nitrogen income and output. In this balance period it will be observed that the total amount of nitrogen taken in for the six days was 53.108 grams, while the output of nitrogen through the kidneys amounted to 51.07 grams. The nitrogen excreted through the fæces, however, brought the total nitrogen output up to 58.83 grams, thus making a minus balance for the six days of 5.722 grams of nitrogen. During this period the average fuel value of the food per day was 2168 calories. The average daily output of metabolized nitrogen during the period was 8.5 grams, practically identical with the average daily excretion of nitrogen through the kidneys for the entire year, so far as determined. We have here a distinct minus balance, due either to an insufficient amount of proteid food, or an insufficient fuel value.

_Tuesday, February 9, 1904._

Breakfast.—Oatmeal 237.5 grams, butter 10 grams, sugar 35 grams, milk 60 grams, coffee 210 grams.

Lunch.—Macaroni 142 grams, cheese 10.5 grams, bread 71.5 grams, sweet potato 119.5 grams, milk 250 grams.

Dinner.—Bread 80.7 grams, butter 20 grams, mashed potato 176 grams, string beans 77.5 grams, apple pie 82 grams, milk 250 grams.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 237.5 × 0.64 = 1.520 grams.
Butter 10 + 20 = 30.0 × 0.088 = 0.026
Sugar 35.0 × 0.00 = 0.000
Milk 60 + 250 + 250 = 560.0 × 0.52 = 2.912
Coffee 210.0 × 0.10 = 0.210
Macaroni 142.0 × 0.87 = 1.235
Cheese 10.5 × 4.45 = 0.467
Bread 71.5 + 80.7 = 152.2 × 1.36 = 2.069
Sweet potato 119.5 × 0.28 = 0.334
Mashed potato 176.0 × 0.36 = 0.633
String beans 77.5 × 0.26 = 0.201
Apple pie 82.0 × 0.49 = 0.401
------
Total nitrogen in food 10.008 grams.
Total nitrogen in urine 8.460

Fuel value of the food 2094 calories.

_Wednesday, February 10, 1904._

Breakfast.—Oatmeal 299 grams, butter 19 grams, cream 71 grams, sugar 41 grams, coffee 210 grams.

Lunch.—Bread 79 grams, butter 11 grams, boiled potato 155.2 grams, milk 250 grams.

Dinner.—Bread 56 grams, butter 12 grams, baked beans 100 grams, cranberry sauce 150 grams, sugar 21 grams, coffee 210 grams.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 99.0 × 0.60 = 1.794 grams.
Butter 19 + 11 + 12 = 42.0 × 0.088 = 0.036
Cream 71.0 × 0.47 = 0.333
Sugar 41 + 21 = 62.0 × 0.00 = 0.000
Coffee (breakfast) 210.0 × 0.12 = 0.252
Bread 79 + 56 = 135.0 × 1.65 = 2.227
Boiled potato 155.2 × 0.39 = 0.605
Milk 250.0 × 0.55 = 1.375
Baked beans 100.0 × 1.40 = 1.400
Cranberry sauce 150.0 × 0.04 = 0.060
Coffee (dinner) 210.0 × 0.11 = 0.231
------
Total nitrogen in food 8.313 grams.
Total nitrogen in urine 8.570

Fuel value of the food 1723 calories.

_Thursday, February 11, 1904._

Breakfast.—Oatmeal 300 grams, cream 71 grams, butter 10 grams, sugar 41 grams, coffee 210 grams.

Lunch.—Butter 14 grams, bread 126 grams, boiled sweet potato 205 grams, milk 250 grams.

Dinner.—Bread 22 grams, butter 7.5 grams, mashed potato 100 grams, sugar 14 grams, milk 250 grams.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 300.0 × 0.40 = 1.200 grams.
Cream 71.0 × 0.49 = 0.347
Butter 10 + 14 + 7.5 = 31.5 × 0.088 = 0.027
Sugar 41 + 14 = 55.0 × 0.00 = 0.000
Coffee 210.0 × 0.096 = 0.201
Bread 126 + 22 = 148.0 × 1.75 = 2.590
Sweet potato 205.0 × 0.31 = 0.635
Milk 250 + 250 = 500.0 × 0.51 = 2.550
Mashed potato 100.0 × 0.36 = 0.360
------
Total nitrogen in food 7.910 grams.
Total nitrogen in urine 8.550

Fuel value of the food 1979 calories.

_Friday, February 12, 1904._

Breakfast.—Oatmeal 300 grams, butter 10 grams, cream 74 grams, sugar 41 grams, coffee 210 grams.

Lunch.—Bread 86 grams, butter 9 grams, potato 200 grams, sugar 14 grams, milk 250 grams.

Dinner.—Bread 63 grams, butter 14 grams, mashed potato 150 grams, apple dumpling 136 grams, milk 250 grams.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 300 × 0.52 = 1.560 grams.
Butter 10 + 9 + 14 = 33 × 0.088 = 0.029
Cream 74 × 0.50 = 0.370
Sugar 41 + 14 = 55 × 0.00 = 0.000
Coffee 210 × 0.11 = 0.231
Bread 86 + 63 = 149 × 1.71 = 2.547
Potato 200 × 0.41 = 0.820
Milk 250 + 250 = 500 × 0.48 = 2.400
Mashed potato 150 × 0.37 = 0.555
Apple dumpling 136 × 0.72 = 0.979
------
Total nitrogen in food 9.491 grams.
Total nitrogen in urine 8.460

Fuel value of the food 2209 calories.

_Saturday, February 13, 1904._

Breakfast.—Oatmeal 300 grams, butter 12 grams, cream 70 grams, sugar 41 grams, coffee 210 grams.

Lunch.—Bread 80 grams, butter 11 grams, sweet potato 132 grams, sugar 20 grams, milk 250 grams.

Dinner.—Bread 59.5 grams, mashed potato 175 grams, butter 11 grams, sugar 20 grams, apple pie 141 grams, milk 250 grams.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 300.0 × 0.43 = 1.290 grams.
Butter 12 + 11 + 11 = 34.0 × 0.088 = 0.029
Cream 70.0 × 0.50 = 0.350
Sugar 41 + 20 + 20 = 81.0 × 0.00 = 0.000
Coffee 210.0 × 0.11 = 0.231
Bread 80 + 59.5 = 139.5 × 1.64 = 2.287
Sweet potato 132.0 × 0.37 = 0.488
Milk 250 + 250 = 500.0 × 0.54 = 2.700
Mashed potato 175.0 × 0.37 = 0.647
Apple pie 141.0 × 0.43 = 0.606
------
Total nitrogen in food 8.628 grams.
Total nitrogen in urine 8.750

Fuel value of the food 2395 calories.

_Sunday, February 14, 1904._

Breakfast.—Oatmeal 300 grams, butter 16 grams, cream 70 grams, sugar 41 grams, coffee 210 grams.

Lunch.—Baked potato 171 grams, bread 72 grams, butter 15 grams, sugar 21 grams, apple sauce 38 grams, milk 250 grams.

Dinner.—Bread 35.5 grams, butter 13.5 grams, mashed potato 180 grams, sugar 20 grams, chocolate cake 111 grams, ice cream 115 grams, milk 250 grams.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 300.0 × 0.46 = 1.380 grams.
Butter 16 + 15 + 13.5 = 44.5 × 0.088 = 0.039
Cream 70.0 × 0.50 = 0.350
Sugar 41 + 21 + 20 = 82.0 × 0.00 = 0.000
Coffee 210.0 × 0.11 = 0.231
Baked potato 171.0 × 0.41 = 0.701
Bread 72 + 35.5 = 107.5 × 1.75 = 1.881
Apple sauce 38.0 × 0.029 = 0.011
Milk 250 + 250 = 500.0 × 0.40 = 2.000
Mashed potato 180.0 × 0.37 = 0.666
Chocolate cake 111.0 × 0.75 = 0.832
Ice cream 115.0 × 0.58 = 0.667
------
Total nitrogen in food 8.758 grams.
Total nitrogen in urine 8.280

Fuel value of the food 2610 calories.

NITROGEN BALANCE.—_Beers._

Nitrogen Output.
Taken in. Nitrogen in Urine. Weight of Fæces (dry).

Feb. 9 10.008 grams. 8.46 grams.
10 8.313 8.57 44.7 grams.
11 7.910 8.55 19.0
12 9.491 8.46 30.0
13 8.628 8.75 28.0
14 8.758 8.28 5.0
------ ------ ------
126.7 grams contain 6.13% N.
53.108 51.07 + 7.76 grams nitrogen.
------ ----------------------
53.108 grams nitrogen. 58.83 grams nitrogen.

Nitrogen balance for six days = -5.722 grams.
Nitrogen balance per day = -0.953 gram.

Average Intake.

Calories per day 2168.
Nitrogen per day 8.85 grams.

On May 6, a second nitrogen balance was attempted covering a period of seven days, in which, as before, there was an exact comparison of the income and output of nitrogen. In this period of seven days, as shown in the accompanying tables, the fuel value of the food was essentially the same as in the preceding period, but the amount of proteid food was increased to an average intake of 10.10 grams per day. Under these conditions there was a distinct plus balance for the seven days amounting to 2.425 grams, thus showing that with this quantity of nitrogenous food the body was laying on nitrogen to the extent of 0.346 gram per day. The average daily amount of nitrogen metabolized during this period was only 8.18 grams, being quite noticeably below the average daily amount for the year. In other words, the results of this balance period show that with a consumption of food sufficient to yield about 2200 calories per day, the body of this subject needed to metabolize only 8.25 grams of nitrogen per day to more than maintain nitrogen equilibrium. Following are the tables of results:

_Friday, May 6, 1904._

Breakfast.—Oatmeal 345 grams, butter 7 grams, sugar 30 grams, milk 100 grams, coffee 180 grams.

Dinner.—Bread 67 grams, potato 71 grams, corn 179 grams, pie 133 grams, milk 200 grams.

Supper.—Biscuit 75 grams, butter 11 grams, potato 106 grams, cake 52 grams, apricots 75 grams, milk 230 grams.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 345 × 0.40 = 1.380 grams.
Butter 7 + 11 = 18 × 0.11 = 0.020
Sugar 30 × 0.00 = 0.000
Milk 100 + 200 + 230 = 530 × 0.54 = 2.862
Coffee 180 × 0.14 = 0.252
Bread 67 × 1.39 = 0.931
Potato (dinner) 71 × 0.52 = 0.369
Corn 179 × 0.44 = 0.788
Pie 133 × 0.54 = 0.718
Biscuit 75 × 1.21 = 0.908
Potato (supper) 106 × 0.36 = 0.382
Cake 52 × 0.90 = 0.468
Apricots 75 × 0.21 = 0.158
------
Total nitrogen in food 9.236 grams.
Total nitrogen in urine 8.720

Fuel value of the food 2080 calories.

_Saturday, May 7, 1904._

Breakfast.—Oatmeal 382 grams, milk 100 grams, coffee 185 grams, butter 10 grams, sugar 30 grams.

Dinner.—Bread 93 grams, potato 67 grams, rice pudding 141 grams, milk 200 grams.

Supper.—Bread 67 grams, butter 13 grams, potato salad 122 grams, milk 240 grams, coffee 120 grams.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 382 × 0.41 = 1.566 grams.
Milk 100 + 200 + 240 = 540 × 0.54 = 2.916
Coffee (breakfast) 185 × 0.13 = 0.241
Butter 10 + 13 = 23 × 0.11 = 0.025
Sugar 30 × 0.00 = 0.000
Bread 93 + 67 = 160 × 1.33 = 2.128
Potato 67 × 0.56 = 0.375
Rice pudding 141 × 0.76 = 1.072
Potato salad 122 × 0.35 = 0.427
Coffee (supper) 120 × 0.15 = 0.180
------
Total nitrogen in food 8.930 grams.
Total nitrogen in urine 8.530

Fuel value of the food 1714 calories.

_Sunday, May 8, 1904._

Breakfast.—Oatmeal 386 grams, butter 10 grams, sugar 35 grams, milk 100 grams, coffee 185 grams.

Dinner.—Rice and chicken gravy 178 grams, boiled onions 136 grams, chocolate pudding 141 grams, milk 150 grams.

Supper.—Potato salad 73 grams, bread 28 grams, chocolate cake 104 grams, milk 220 grams.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 386 × 0.35 = 1.351 grams.
Butter 10 × 0.11 = 0.011
Sugar 35 × 0.00 = 0.000
Milk 100 + 150 + 220 = 470 × 0.55 = 2.585
Coffee 185 × 0.11 = 0.204
Rice and chicken gravy 178 × 0.47 = 0.837
Onions 136 × 0.25 = 0.340
Chocolate pudding 141 × 1.03 = 1.452
Potato salad 73 × 0.35 = 0.256
Bread 28 × 1.33 = 0.372
Chocolate cake 104 × 0.95 = 0.988
------
Total nitrogen in food 8.396 grams.
Total nitrogen in urine 7.000

Fuel value of the food 1995 calories.

_Monday, May 9, 1904._

Breakfast.—Oatmeal 330 grams, butter 10 grams, sugar 35 grams, milk 100 grams, coffee 185 grams.

Dinner.—Bread 73 grams, fried potato 125 grams, boiled onions 118 grams, macaroni and cheese 128 grams, apple pie 110 grams, milk 200 grams.

Supper.—Bread 82 grams, boiled potato 130 grams, butter 12 grams, chocolate cake 114 grams, milk 245 grams.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 330 × 0.44 = 1.452 grams.
Butter 12 + 10 = 22 × 0.11 = 0.024
Sugar 35 × 0.00 = 0.000
Milk 100 + 200 + 245 = 545 × 0.58 = 3.161
Coffee 185 × 0.099 = 0.183
Bread 73 + 82 = 155 × 1.33 = 2.062
Fried potato 125 × 0.48 = 0.600
Onions 118 × 0.25 = 0.295
Macaroni and cheese 128 × 1.53 = 1.958
Apple pie 110 × 0.55 = 0.605
Boiled potato 130 × 0.30 = 0.390
Chocolate cake 114 × 0.95 = 1.083
------
Total nitrogen in food 11.813 grams.
Total nitrogen in urine 7.590

Fuel value of the food 2620 calories.

_Tuesday, May 10, 1904._

Breakfast.—Oatmeal 357 grams, butter 11 grams, sugar 35 grams, milk 100 grams, coffee 185 grams.

Dinner.—Soda biscuit 68 grams, boiled potato 160 grams, butter 20 grams, stewed tomato 103 grams, custard pie 103 grams, milk 200 grams.

Supper.—Soda biscuit 81 grams, butter 14 grams, stewed potato 97 grams, chocolate cake 66 grams, milk 200 grams.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 357 × 0.42 = 1.499 grams.
Butter 11 + 20 + 14 = 45 × 0.11 = 0.050
Sugar 35 × 0.00 = 0.000
Milk 100 + 200 + 200 = 500 × 0.54 = 2.700
Coffee 185 × 0.13 = 0.241
Soda biscuit 68 + 81 = 149 × 1.27 = 1.892
Boiled potato 160 × 0.30 = 0.480
Stewed tomato 103 × 0.21 = 0.216
Custard pie 103 × 0.91 = 0.937
Stewed potato 97 × 0.45 = 0.437
Chocolate cake 66 × 0.95 = 0.627
------
Total nitrogen in food 9.079 grams.
Total nitrogen in urine 7.780

Fuel value of the food 2190 calories.

_Wednesday, May 11, 1904._

Breakfast.—Oatmeal 394 grams, butter 10 grams, sugar 35 grams, milk 100 grams, coffee 185 grams.

Dinner.—Soup 141 grams, bread 78 grams, butter 14 grams, boiled potato 101 grams, corn 128 grams, rice pudding 116 grams, milk 200 grams.

Supper.—Biscuit 103 grams, butter 11 grams, corn 113 grams, cake 60 grams, milk 205 grams.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 394 × 0.46 = 1.812 grams.
Butter 10 + 14 + 11 = 35 × 0.11 = 0.039
Sugar 35 × 0.00 = 0.000
Milk 100 + 200 + 205 = 505 × 0.54 = 2.727
Coffee 185 × 0.13 = 0.241
Soup 141 × 0.48 = 0.677
Bread 78 × 1.25 = 0.975
Boiled potato 101 × 0.31 = 0.313
Corn 113 + 128 = 241 × 0.46 = 1.109
Rice pudding 116 × 0.63 = 0.731
Biscuit 103 × 1.42 = 1.463
Cake 60 × 0.78 = 0.468
------
Total nitrogen in food 10.555 grams.
Total nitrogen in urine 8.280

Fuel value of the food 2183 calories.

_Thursday, May 12, 1904._

Breakfast.—Oatmeal 349 grams, butter 10 grams, sugar 35 grams, milk 100 grams, coffee 185 grams.

Dinner.—Soup 137 grams, fried potato 43 grams, bread 100 grams, macaroni and cheese 122 grams, bread pudding 80 grams, milk 200 grams.

Supper.—Stewed potato 126 grams, bread 122 grams, cake 73 grams, apricots 81 grams, milk 220 grams.

Food. Grams. Per cent Nitrogen. Total Nitrogen.

Oatmeal 349 × 0.41 = 1.431 grams.
Butter 10 × 0.11 = 0.011
Sugar 35 × 0.00 = 0.000
Milk 100 + 200 + 220 = 520 × 0.57 = 2.964
Coffee 185 × 0.13 = 0.241
Soup 137 × 0.48 = 0.658
Fried potato 43 × 0.76 = 0.327
Bread 100 + 122 = 222 × 1.25 = 2.775
Macaroni and cheese 122 × 1.94 = 2.370
Bread pudding 80 × 0.82 = 0.656
Stewed potato 126 × 0.43 = 0.542
Cake 73 × 0.78 = 0.569
Apricots 81 × 0.23 = 0.186
------
Total nitrogen in food 12.730 grams.
Total nitrogen in urine 9.360

Fuel value of the food 2283 calories.

NITROGEN BALANCE.—_Beers._

Nitrogen Output.
Taken in. Nitrogen in Urine. Weight of Fæces (dry).

May 6 9.236 grams. 8.72 grams. 17.5 grams.
7 8.930 8.53 30.5
8 8.396 7.00 26.2
9 11.813 7.59 27.1
10 9.079 7.78 22.1
11 10.555 8.28 26.0
12 12.730 9.36 24.5
12.5
------ ------ ------
186.4 grams contain 5.93% N.
70.739 57.26 + 11.054 grams nitrogen.
------ ----------------------
70.739 grams nitrogen. 68.314 grams nitrogen.

Nitrogen balance for seven days = +2.425 grams.
Nitrogen balance per day = +0.346 gram.

Average Intake.

Calories per day 2152.
Nitrogen per day 10.10 grams.

Here we have, as in the preceding cases, marked physiological economy of non-nitrogenous as well as of nitrogenous food material. Further, taking the body-weight of the subject as 61.5 kilos, and with an average daily excretion of 8.58 grams of metabolized nitrogen, it is evident that under the existing conditions of life and activity there was need for the metabolism of only 0.139 gram of nitrogen per kilo of body-weight. Doubtless, however, still greater economy was possible.

Finally, while it hardly savors of scientific accuracy to quote simple sensations, yet it may be stated that the subject asserts a betterment of his condition, with continuance of mental and physical vigor in such a degree that he has persisted now for more than a year and a half in the maintenance of these dietetic habits which are characterized by this lowered rate of proteid metabolism. The quantity of nitrogen metabolized daily means the breaking down of approximately 50 grams of proteid, and it is very evident that this amount of proteid food, one-half the amount called for by the ordinary diet, is quite sufficient to meet all of the subject’s bodily needs, even with a total fuel value considerably below 2500 calories.

SUMMARY

Certain general conclusions seem to be justified by the results reported. A healthy man, whose occupation is such as not to involve excessive muscular work, but whose activity is mainly mental rather than physical, though by no means excluding the latter, can live on a much smaller amount of proteid or albuminous food than is usually considered essential for life, without loss of mental or physical strength and vigor, and with maintenance of body and nitrogen equilibrium. This means that the ordinary professional man who leads an active and even strenuous life, with its burden of care and responsibility, need not clog his system and inhibit his power for work by the ingestion of any such quantities of proteid food as the ordinary dietetic standards call for. There is no real physiological need—that is apparent—for the adoption of such dietetic habits as ordinarily prevail, or as are called for by the dietary standards set by most authorities in this branch of physiology. There is no justifiable ground for the dictum, or the assumption, that the adult man of average body-weight needs daily 118 grams of proteid food for the maintenance of health, strength and vigor, or that there is need for the metabolism of at least 16 grams of nitrogen daily. If such were the case, how could these five subjects, whose experiences have been detailed in the foregoing pages, have maintained their body-weight, established nitrogen equilibrium, pursued their ordinary vocations without loss of strength and vigor, and kept in a perpetual condition of good health, with an average daily metabolism of from 5.4 grams of nitrogen to 8.99 grams of nitrogen for periods ranging from six to eighteen months? Surely, if 16 to 18 grams of nitrogen are a daily requisite for the healthy adult, there should have been some sign of nitrogen starvation during these long periods of low proteid diet, but the sharpest scrutiny failed to find it. On the contrary, there were not wanting signs of improved conditions of the body which could not well be associated with anything but the changes in diet.

Let us briefly consider the main facts. The writer, of 57 kilos body-weight, showed for nearly nine consecutive months an average daily metabolism of 5.7 grams of nitrogen. During the last two months the daily metabolism averaged 5.4 grams of nitrogen. As body-weight and nitrogen equilibrium were both maintained under these conditions, it is certainly fair to assume that the physiological needs of the body were fully met. These figures imply a metabolism, in the first instance, of 0.1 gram of nitrogen per kilo of body-weight, while the lower figure shows a metabolism of 0.094 gram of nitrogen per kilo of body-weight. We may call this latter amount the minimal nitrogen requirement for this particular individual, under which health, strength, and vigor can be fully maintained. This lower nitrogen figure shows that the needs of this particular individual for proteid material are met by the metabolism of 33.75 grams of proteid per day. Hence, one-third the usually accepted standard of proteid is quite sufficient for the wants of this particular person, and this too with a quantity of non-nitrogenous food far below the daily amount called for by ordinary physiological rules. A fuel value of 2000 calories per day was fully adequate to meet the ordinary wants of the body.

Dr. Mendel, with a body-weight of 70 kilos, showed for seven consecutive months an average daily metabolism of 6.53 grams of nitrogen, likewise with maintenance of health, strength, body equilibrium, and nitrogenous equilibrium. This figure implies a nitrogen metabolism of 0.093 gram per kilo of body-weight and shows that the wants of the body—in his case—can be fully met by a metabolism of 40.8 grams of proteid matter daily, and this likewise without increasing the amount of non-nitrogenous food ingested. Indeed, a total fuel value of 2500 calories per day was quite sufficient for all the needs of his body under the existing conditions.

Dr. Underhill, with a body-weight of 65 kilos, showed for six consecutive months a proteid metabolism equal to 7.81 grams of nitrogen per day, while for the last two months the daily average excretion of nitrogen was only 6.68 grams. These figures mean respectively a nitrogen metabolism of 0.120 and 0.102 gram of nitrogen per kilo of body-weight. Here, too, as in the preceding cases, this lowered rate of proteid metabolism was maintained without increasing the total fuel value of the food and with a continuance of health and strength.

Messrs. Dean and Beers, with body-weights of 64 and 61.5 kilos respectively, likewise kept up their health and strength for a long period of time with a nitrogen metabolism averaging 8.99 and 8.58 grams of nitrogen per day, _i. e._, with a metabolism of 0.140 and 0.139 gram of nitrogen per kilo of body-weight respectively, and this with a total fuel value in their daily food averaging not more than 2500 calories.

With this general concurrence of results, we are certainly warranted in the assertion that the professional man can safely practise a physiological economy in the use of proteid food equal to a saving of one-half to two-thirds the amount called for by existing dietary standards, and this without increasing the amount of non-nitrogenous food consumed. Indeed, the latter class of foods can likewise be diminished in amount without detriment to health or strength, where there is no call for great physical exertion. Lastly, the so-called minimal proteid requirement of the healthy man—which for this group of individuals we may place at the low level of 0.093 to 0.130 gram of nitrogen per kilo of body-weight—represents the real physiological needs of the system for nitrogen, and in so far as our present data show, anything beyond this quantity may be considered as an excess over and above what is required for the actual physiological necessities of the body. Naturally, however, there may be nothing detrimental in a slight excess of proteid beyond the daily needs. That is a subject, however, to be discussed later in connection with other results.

In view of the close agreement in the amount of nitrogen metabolized by these different individuals per kilo of body-weight, emphasis should be laid upon the fact that the results recorded were all obtained with perfect freedom of choice in the matter of diet, without prescription of any kind, so that the close concurrence in the final figures tends to strengthen the value of the data as pointing to a certain minimal requirement easily attainable, and fully adequate for meeting the needs of the body.