CHITTENDEN.

Date.Body-weight.Urine.
Volume. 24 hours.Sp. Gr.Nitrogen.Uric Acid.P₂O₅.
1903kilosc.c.gramsgramgrams
Oct.1357.538010275.460.3761.10
1455010276.51
1540010225.400.3521.02
1650010276.45
1757.447710306.40
1867010277.200.4061.10
1943510276.13
2046510286.830.4760.92
2145010296.51
2246510276.140.3700.96
2744510235.520.3850.79
2840510275.08
Nov.139010295.680.3720.42
253010276.33
347010275.920.4120.75
442510285.88
537510294.930.3300.79
754510286.57
857.445610295.820.3710.65
941510275.43
1061510256.450.4301.17
1141010284.80
1258010265.640.3711.02
1358410275.82
1450510296.36
1540510285.800.3840.73
1642510275.43
1745510285.270.3670.76
1857510276.62
1944710275.340.3890.77
2048010296.00
2157.540010295.71
2238210295.520.3790.97
2357.735010295.33
2442210296.430.400
2543510305.79
2657.644510306.090.4301.01
2743010306.17
2945410275.660.4200.93
3045510235.56
Dec.142010285.310.4500.92
246510276.17
343010275.340.3500.82
436510294.77
543010305.83
651510285.900.3931.08
740010285.57
839010284.990.3281.02
940510305.17
1057.637010264.640.3080.90
1132710304.650.3251.11
1239010275.160.3461.01
1342910295.66
1436010304.84
1529510294.320.2910.82
1644510296.27
1739010325.590.3580.73
1842010305.62
1941510275.03
2057.539010305.710.4020.78
2136010234.25
2236010305.130.3420.79
2340010315.08
2443510306.44
2545010295.130.3290.77
264655.55
274705.53
285358.18
295357.67
306569.68
3157.649010317.610.4550.92
1904
Jan.141510306.41
249010316.56
346010305.910.3190.79
458.143010305.72
557010286.360.402
644510285.68
751010285.910.3670.99
842010285.37
965010277.29
1063510246.320.4140.99
1141010284.87
1245010276.48
1341010275.340.435
1453210286.220.502
1553010285.98
1651510306.18
1753710306.730.429
1857.839510295.09
1945010305.720.427
2042010264.76
2141010295.260.401
2248510295.41
2344010315.07
2448510295.610.407
2554510276.18
2648510286.690.440
2743510285.64
2849010296.180.423
2945010295.68
304755.590.376
314906.61
Feb.149010306.47
257.540010316.120.219
341510305.85
454510276.770.327
545010305.64
648510276.01
745010265.62
857.441510275.88
954010266.670.449
1041010295.61
1160010256.70
1243010295.570.437
1341510285.50
1448010286.420.497
1539510304.95
1650010295.970.364
1745010305.62
1857.343010305.860.279
1945010296.21
2045510275.46
2150010276.160.424
2244510285.15
2345510275.63
2442010286.27
2556010276.280.403
2663010266.27
2757010266.87
2851510286.270.496
2945010305.43
Mar.145010276.02
244510295.15
359010286.30
441510295.40
557.542510275.48
654810255.920.370
740010294.68
853010285.77
956010285.84
1056010285.64
1149510285.79
1251510216.80
1352010296.430.370
1460010256.12
1552010265.87
1657.552510265.13
1749010264.97
1845010275.08
1950010245.85
2050010225.910.321
daily
average
1.20
daily
average
2157.443010255.52
2245810335.94
2357.240010295.61
2457.336510294.31
2542010295.39
2657.543510275.85
2759510266.33
2854510276.00
2943510284.86
3057510266.26
3149510265.26
Apr.157010266.33
244010306.07
348710266.110.375
441010285.78
539010285.38
656.849010285.56
756.553010275.69
844010295.41
946510196.05
1056.850010296.000.382
1150010286.18
1256.447510295.550.3660.870
Daily average
for six months
46610275.820.3860.899
1354510296.77
1444010275.89
1550010285.91
1648510285.49
1740510295.990.393
1846510296.11
1951010307.68
2043010316.99
2156.661510298.67
2232010305.03
2357.135510325.72
2445510275.97
2538010274.93
2645010284.970.366
2760010256.620.553
2856.938510295.660.507
2941510295.280.488
3056.946210295.590.413
May148610275.540.409
240510284.110.320
357.150510275.48
445610265.27
538010264.88
653010276.30
747010245.44
857.646010275.07
946010264.28
1057.449310285.26
1141510294.61
1253010295.98
1341510314.72
1457.240510314.980.468
1550010295.31
1650510275.03
1765010205.69
1855010275.81
1956010276.05
2061510276.64
2156.938010325.200.421
2247510285.73
2337810284.60
2438310294.48
2553510255.14
2656.935510284.37
2743510264.93
2857.555510285.990.397
2957.756510276.27
3070010205.50
3150010255.13
June163010235.41
251010204.16
353010235.25
457.639010295.25
540010254.87
643010275.16
748010285.15
841010274.95
942010264.51
1039510264.27
1157.551010305.91
1253010275.95
1357.648510275.35
1447010305.16
1556010244.91
1657.639010295.26
1740810275.17
1857.941210305.07
1945810255.44
2058.038010264.49
2148010235.04
2257.858010256.16
2357.953510255.260.397
daily
average
1.08
daily
average
2457.657010245.30
2541010274.43
2657.440010274.66
2757.440510274.98
Daily average from Oct. 13, 190346810275.690.3920.904
Daily average from April 13 to June 275.40
June2857.559510266.75

Scrutiny of the tables shows that during this period of nine months the body-weight was practically constant. The daily volume of urine was exceptionally small and fairly regular in amount, the average daily output for the nine months being 468 c.c. It is a noticeable fact that with a diminished intake of proteid food there is far less thirst, and consequently a greatly decreased demand for water or other fluids. Further, in view of the small nitrogenous waste there is no need on the part of the body for any large amount of fluid to flush out the kidneys. The writer has not had a turbid urine during the nine months’ period. With heavier eating of nitrogenous foods, an abundant water supply is a necessity to prevent the kidneys from becoming clogged, thereby explaining the frequent beneficial results of the copious libations of mineral waters, spring waters, etc., frequently called for after, or with, heavy eating. Obviously, a small volume of urine each day means so much less wear and tear of the delicate mechanism of the kidneys. Somewhat noticeable, in a general way, is the apparent relationship between the volume of the urine and the nitrogen output, in harmony with the well-known diuretic action of urea. The specific gravity of the urine shows variation only within narrow limits, the daily average for the nine months being 1027.

Uric acid is noticeably small in quantity, the average daily output for the nine months’ period, based upon the determinations made, being only 0.392 gram.

Chief interest, however, centres around the figures for total nitrogen, since these figures give for each day the extent of the proteid metabolism; i. e., the amount of proteid material broken down in the body each day in connection with the wear and tear of the bodily machinery. To fully grasp the significance of these data, it should be remembered that the prevalent dietary standards are based upon the assumption that the average adult must metabolize each day at least 16 grams of nitrogen. Indeed, that is what actual analysis of the urine indicates in most cases. If now we look carefully through the figures shown in the above tables, covering a period from October 13, 1903, to June 28, 1904, it is seen that the daily nitrogen excretion is far different from 16 grams. Indeed, the figures for nitrogen are exceedingly low, and, moreover, they vary little from day to day. The average daily output of nitrogen through the urine for the entire period of nearly nine months is only 5.699 grams.

For the first six months the average daily excretion amounted to 5.82 grams of nitrogen, while from April 12 to June 28 the average daily excretion of nitrogen was 5.40 grams, thus showing a slight tendency downward. On the whole, however, there is shown a somewhat remarkable uniformity in the daily excretion. Thus, the average daily excretion for the month of November was 5.79 grams of nitrogen, for the month of March 5.66 grams, thus showing very little difference in the output of nitrogen through the kidneys in these two periods, three months apart. In other words, the extent of proteid katabolism was essentially the same throughout the entire nine months, implying that the amount of proteid food eaten must have been fairly constant, and that the body had adapted itself to this new level of nutrition from which there was no tendency to deviate. There was no weighing out of food and no attempt to follow any specified diet. The greatest possible variety of simple foods was indulged in, and the dictates of the appetite were followed with the single precaution that excess was avoided. In other words, it was temperance in diet, and not prohibition. Yet it is equally true, in the writer’s case at least, that the appetite itself unconsciously served as a regulator, since there was, as a rule, no necessity to hold the appetite in check to avoid excess. Doubtless, the writer’s knowledge of the general composition of food-stuffs has had some influence in the choice of foods, and thereby aided in bringing about this somewhat remarkable uniformity in the daily output of nitrogen for such a long period of time on an unrestricted diet.

What now do the nitrogen figures show regarding the amount of proteid material metabolized each day? It will be remembered that the Voit standard calls for 118 grams of proteid or albuminous food daily, of which 105 grams should be absorbable, in order to maintain the body in a condition of nitrogen equilibrium, and in a state of physical vigor and general tone. This would mean a daily excretion through the urine of at least 16 grams of nitrogen. The daily output of nitrogen in the case under discussion, however, was 5.699 grams for a period of nearly nine months. This amount of nitrogen excreted through the urine means only 35.6 grams of proteid metabolized, or about one-third the amount called for by the Voit standard, or the standards generally adopted as expressing man’s daily requirement of proteid food. But was the body in nitrogenous equilibrium on this small amount of proteid food? Naturally, this question might be answered in the affirmative, on the basis of the constancy in body-weight for the period from October to June, but more decisive proof is needed. The question was therefore settled by a careful comparison of the income and output, in which all the food eaten was carefully weighed and analyzed, while the nitrogen of the urine and fæces was determined with equal accuracy. The first experiment of this character to be quoted is for the week commencing March 20, a period of six days.

Following are the diets made use of each day, the weights of the various food-stuffs being given in grams. Likewise is shown the nitrogen content of the several food-stuffs for each day, and also a comparison of the nitrogen intake with the output of nitrogen through the urine:

Sunday, March 20, 1904.

Breakfast, 7.45 A. M.—One cup coffee, i. e., coffee 137.5 grams, cream 30.5 grams, sugar 9 grams.

Dinner, 1.30 P. M.—Stewed chicken 50 grams, mashed potato 131 grams, biscuit 49 grams, butter 13 grams, chocolate pudding 106 grams, one small cup coffee, i. e., coffee 64 grams, sugar 12 grams, cheese crackers 29 grams.

Supper, 6.30 P. M.—Lettuce sandwiches 56 grams, biscuit 35 grams, butter 6 grams, one cup tea, i. e., tea 170 grams, sugar 7 grams, sponge cake 47 grams, sliced oranges 82 grams.

Food.Grams.Per cent Nitrogen.Total Nitrogen.
Coffee64 + 137 =201.5×0.042=0.085gram.
Cream30.5×0.41=0.125
Sugar12 + 9 + 7 =28.0×0.00=0.000
Chicken50.0×4.70=2.350
Mashed potato131.0×0.30=0.393
Biscuit35 + 49 =84.0×1.49=1.251
Butter13 + 6 =19.0×0.10=0.019
Chocolate pudding106.0×0.86=0.911
Cheese crackers29.0×2.54=0.737
Lettuce sandwich56.0×0.92=0.515
Tea170.0×0.048=0.082
Sponge cake47.0×0.98=0.461
Sliced orange82.0×0.073=0.060
Total nitrogen in food6.989grams.
Total nitrogen in urine5.910
Fuel value of the food1708 calories.[32]

Monday, March 21, 1904.

Breakfast, 7.45 A. M.—Coffee 119 grams, cream 30 grams, sugar 9 grams.

Lunch, 1.30 P. M.—One shredded wheat biscuit 31 grams, cream 116 grams, wheat gems 33 grams, butter 7 grams, tea 185 grams, sugar 10 grams, cream cake 53 grams.

Dinner, 6.30 P. M.—Pea soup 114 grams, lamb chop 24 grams, boiled sweet potato 47 grams, wheat gems 76 grams, butter 13 grams, cream cake 52 grams, coffee 61 grams, sugar 10 grams, cheese crackers 16 grams.

Food.Grams.Per cent Nitrogen.Total Nitrogen.
Coffee119 + 61 =180×0.042=0.076gram.
Cream30 + 116 =146×0.41=0.600
Sugar9 + 10 + 10 =29×0.00=0.000
Shredded wheat biscuit31×1.62=0.502
Tea185×0.048=0.089
Wheat gems33 + 76 =109×1.46=1.591
Butter7 + 13 =20×0.10=0.020
Cream cake53 + 52 =105×0.97=1.018
Pea soup114×1.00=1.140
Lamb chop24×4.54=1.090
Sweet potato47×0.18=0.085
Cheese crackers16×2.54=0.410
Total nitrogen in food6.621grams.
Total nitrogen in urine5.520
Fuel value of the food1713 calories.

Tuesday, March 22, 1904.

Breakfast, 7.45 A. M.—Coffee 97 grams, cream 26 grams, sugar 9 grams.

Lunch, 1.30 P. M.—Baked potato 83 grams, fried sausage 36 grams, soda biscuit 39 grams, butter 12 grams, tea 137 grams, sugar 10 grams, cream meringue 59 grams.

Dinner, 6.30 P. M.—Chicken broth 146 grams, bread 52 grams, butter 15 grams, creamed potato 76 grams, custard 76 grams, coffee 50 grams, sugar 11 grams, cheese crackers 10 grams.

Food.Grams.Per cent Nitrogen.Total Nitrogen.
Coffee97 + 50 =147×0.042=0.060gram.
Cream26×0.42=0.109
Sugar9 + 10 + 11 =30×0.00=0.000
Baked potato83×0.40=0.332
Fried sausage36×3.06=1.101
Soda biscuit39×1.66=0.647
Butter12 + 15 =27×0.10=0.027
Tea137×0.048=0.066
Cream meringue59×0.92=0.543
Chicken broth146×0.78=1.138
Bread52×1.66=0.863
Creamed potato76×0.42=0.319
Custard76×0.82=0.623
Cheese crackers10×2.54=0.254
Total nitrogen in food6.082grams.
Total nitrogen in urine5.940
Fuel value of the food1398 calories.

Wednesday, March 23, 1904.

Breakfast, 7.45 A. M.—Coffee 103 grams, cream 30 grams, sugar 10 grams.

Lunch, 1.30 P. M.—Creamed codfish 64 grams, potato balls 54 grams, biscuit 44 grams, butter 22 grams, tea 120 grams, sugar 10 grams, wheat griddle cakes 133 grams, maple syrup 108 grams.

Dinner, 6.30 P. M.—Creamed potato 85 grams, biscuit 53 grams, butter 15 grams, apple-celery-lettuce salad 50 grams, apple pie 127 grams, coffee 67 grams, sugar 8 grams, cheese crackers 17 grams.

Food.Grams.Per cent Nitrogen.Total Nitrogen.
Coffee103 + 67 =170×0.042=0.071gram.
Sugar10 + 10 + 8 =28×0.00=0.000
Cream30×0.43=0.129
Potato balls54×0.68=0.367
Creamed codfish64×1.26=0.806
Biscuit44 + 53 =97×1.66=1.610
Butter22 + 15 =37×0.10=0.037
Tea120×0.048=0.058
Wheat griddle cakes133×1.32=1.760
Maple syrup108×0.019=0.021
Creamed potato85×0.53=0.450
Cheese crackers17×2.54=0.431
Apple-celery salad50×0.20=0.100
Apple pie127×0.75=0.953
Total nitrogen in food6.793grams.
Total nitrogen in urine5.610
Fuel value of the food1984 calories.

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.

Food.Grams.Per cent Nitrogen.Total Nitrogen.
Coffee100×0.042=0.042gram.
Cream25 + 118 =143×0.43=0.615
Sugar8 + 7 + 10 =25×0.00=0.000
Shredded wheat biscuit29×1.76=0.510
Wheat gems60×1.17=0.702
Butter8 + 1 =9×0.10=0.009
Tea100 + 100 =200×0.048=0.096
Apple pie102×0.75=0.765
Milk-celery soup140×0.42=0.588
Bread15×1.36=0.204
Lettuce sandwich62×1.02=0.632
Lemon pie109×0.82=0.894
Total nitrogen in food5.057grams.
Total nitrogen in urine4.310
Fuel value of the food1594 calories.

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.

Food.Grams.Per cent Nitrogen.Total Nitrogen.
Coffee100 + 70 =170×0.042=0.071gram.
Cream25×0.40=0.100
Sugar9 + 9 + 10 =28×0.00=0.000
Halibut, etc.108×3.02=3.262
Mashed potato89×0.26=0.231
Biscuit48×1.52=0.730
Butter10×0.10=0.010
Tea100×0.048=0.048
Chocolate-cream cake90×0.99=0.891
Celery-milk soup121×0.52=0.629
Lettuce sandwich61×0.98=0.598
Lettuce-apple salad74×0.21=0.155
Creamed potato65×0.37=0.241
Total nitrogen in food6.966grams.
Total nitrogen in urine5.390
Fuel value of the food1285 calories.

NITROGEN BALANCE.—Chittenden.

Nitrogen
Taken in.
Output.
Nitrogen in Urine.Weight of Fæces[33] (dry).
March206.989grams.5.91grams.3.6grams.
216.6215.520.0
226.0825.9412.0
236.7935.6118.5
245.0574.3123.0
256.9665.3916.9
74.0grams contain
6.42% N.
38.50832.68+4.75grams nitrogen.
38.508grams nitrogen.37.43grams nitrogen.
Nitrogen balance for six days=+1.078grams.
Nitrogen balance per day=+0.179gram.

Average Intake.

Calories per day1613.
Nitrogen per day6.40 grams.

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.

Food.Grams.Per cent Nitrogen.Total Nitrogen.
Coffee123 + 53 =176×0.045=0.079gram.
Cream50×0.35=0.175
Sugar11 + 20 + 12 =43×0.00=0.000
Omelette50×1.32=0.660
French fried potatoes70×0.37=0.259
Bacon10×3.43=0.343
Wheat gems43×1.49=0.641
Butter9 + 17 =26×0.13=0.034
Strawberries125×0.11=0.138
Cream cake59×0.98=0.578
Beefsteak34×4.14=1.408
Peas60×0.97=0.582
Creamed potato97×0.34=0.330
Bread26×1.23=0.320
Lettuce-orange salad153×0.15=0.230
Crackers43×1.40=0.602
Cream cheese15×1.62=0.243
Total nitrogen in food6.622grams.
Total nitrogen in urine5.260
Fuel value of the food1863 calories.

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.

Food.Grams.Per cent Nitrogen.Total Nitrogen.
Coffee123 + 53 =176×0.045=0.079gram.
Sugar8 + 26 + 10 =44×0.00=0.000
Milk32×0.51=0.163
Creamed codfish89×1.78=1.584
Baked potato95×0.29=0.276
Butter10 + 11 =21×0.13=0.027
Hominy gems58×1.20=0.696
Strawberries86×0.11=0.095
Ginger snaps47 + 22 =69×1.15=0.794
Cold tongue14×4.87=0.682
Fried potato48×0.37=0.178
Peas60×0.94=0.564
Wheat gems30×1.45=0.435
Lettuce-orange salad, etc.155×0.15=0.233
Crackers22×1.40=0.308
Cream cheese14×1.62=0.227
Total nitrogen in food6.331grams.
Total nitrogen in urine5.300
Fuel value of the food1506 calories.

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.

Food.Grams.Per cent Nitrogen.Total Nitrogen.
Coffee1201 + 48 =149×0.045=0.067gram.
Milk36×0.46=0.166
Sugar13 + 15 + 11 =39×0.00=0.000
Omelette50×1.42=0.710
Bacon9×2.66=0.239
French fried potato23×0.57=0.131
Biscuit29×1.35=0.392
Butter8 + 10 =18×0.13=0.023
Iced tea150×0.018=0.027
Ginger snaps42×1.15=0.483
Cream cheese17 + 21 =38×1.62=0.616
Wheat popovers57×1.64=0.935
Lettuce-orange salad147×0.15=0.221
Crackers22×1.40=0.308
Cottage pudding82×0.76=0.623
Total nitrogen in food4.941grams.
Total nitrogen in urine4.430
Fuel value of the food1392 calories.

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.

Food.Grams.Per cent Nitrogen.Total Nitrogen.
Coffee122×0.045=0.055gram.
Cream31 + 40 =71×0.32=0.227
Sugar8 + 26 + 10 =44×0.00=0.000
Roast lamb50×4.28=2.140
Baked potato52×0.29=0.151
Peas64×1.04=0.666
Biscuit32×1.35=0.432
Butter12×0.13=0.016
Lettuce salad43×0.23=0.099
Cream cheese21×1.62=0.340
Toasted crackers23×1.36=0.313
Blanc mange164×0.35=0.574
Iced tea225×0.018=0.041
Lettuce sandwich51×0.85=0.434
Strawberries130×0.11=0.143
Sponge cake31×0.94=0.291
Total nitrogen in food5.922grams.
Total nitrogen in urine4.660
Fuel value of the food1533 calories.

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.

Food.Grams.Per cent Nitrogen.Total Nitrogen.
Coffee123 + 53 =176×0.045=0.079gram.
Cream22×0.32=0.070
Sugar10 + 25 + 9 =44×0.00=0.000
Iced tea250×0.018=0.045
Baked potato90×0.25=0.225
Wheat gems47×1.65=0.776
Butter12 + 17 =29×0.13=0.038
Roast lamb9×4.28=0.385
Vanilla éclair47×0.85=0.400
Lamb chops32×4.57=1.462
Asparagus49×0.59=0.289
Creamed potato107×0.40=0.428
Bread35×1.33=0.466
Lettuce-orange salad, etc.150×0.23=0.345
Cream cheese12×1.62=0.194
Crackers21×1.35=0.284
Total nitrogen in food5.486grams.
Total nitrogen in urine4.980
Fuel value of the food1454 calories.

NITROGEN BALANCE.—Chittenden.

Nitrogen
Taken in.
Output.
Nitrogen in Urine.Weight of Fæces (dry).
June236.622grams.5.26grams.10.6grams.
246.3315.300.7
254.9414.4314.2
265.9224.6611.9
275.4864.9815.2
82.6grams contain
6.08% N.
29.30224.63+5.022grams nitrogen.
29.302grams nitrogen.29.652grams nitrogen.
Nitrogen balance for five days=-0.350gram.
Nitrogen balance per day=-0.070gram.

Average Intake.

Calories per day1549.
Nitrogen per day5.860 grams.

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.