*Turkey eaten on this day.†On these three days, meat, fish, and eggs were eaten.
*Turkey eaten on this day.
*Turkey eaten on this day.
†On these three days, meat, fish, and eggs were eaten.
†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 metabolizednitrogen 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.
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.
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.
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.
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.
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.
NITROGEN BALANCE.—Beers.
Average Intake.
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.
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.
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.
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.
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.
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.
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.
NITROGEN BALANCE.—Beers.
Average Intake.
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.
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 showsthat 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.