Energy expenditure and food requirements of children …rspb.royalsocietypublishing.org/content/royprsb/94/662/368.full.pdf · calorimetry. It is clear that ... usual proportion of

368

Energy Expenditure and Food Requirements of Children at School.By Miss E. M. Bedale, Lawrence Student.

(Communicated by Prof. E. H. Starling, F.R.S. Received December 20, 1922.)

Introduction.—M ethods...................................................................Section I.—The School.—Boys and girls, 11-18 years

A. Conditions of lifeB. Subjects and experiments ...C. Assessments of daily energy expenditure ...

Section II.—The Junior School.—Boys and girls, 7-12 yearsA. Conditions of lifeB. Subjects and experiments ...C. Assessments of daily energy expenditure ...

Section III.—Dietary studies.—Children, 5-18 years Section IV.—Balance of food intake and energy output, with note on growth Appendix I.—Experiments on children attending the village school. (Summary)Appendix II.—Some new analyses of cooked foods ................ ................R eferences............................................................................................

368370370371 376 388388389390 393 398402403404

The research here reported* was carried out from June, 1919, to June, 1921, at Bedales School in Hampshire.

I t was fortunate that an opportunity for such an investigation should have arisen at a school perhaps better suited for it than any other in the country. Bedales is known to those interested in educational experiments as a school which for twenty-five years has justified the principle of co-education. For the purpose of this enquiry, it has been a great advantage to be able to study simultaneously boys and girls living the same life, and that under admirable conditions. During the second year, I was also enabled to work at the Junior School, which is distinct and separate. I have been given every opportunity of gaining an intimate knowledge of the working of the school, and of the children themselves, and this has been of incalculable value. Such work attempted hastily from outside would almost necessarily be full of gross errors ; only by identifying oneself with the life of the school, can one hope to study truly the activities of the child and adolescent.

* The present paper is a summary of the full report submitted in 1921, which contained the experimental data for all individuals studied. The cost of printing makes it impossible to publish these tables in full. Despite the similarity of the names of the school and of the writer of the paper they are not connected in any way.

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Food Requirements o f Children at School. 369

Methods.

I t was possible to attack the question of normal child-nutrition on two parallel p a th s:—

(1) By a detailed study of the actual food consumption of individuals. The method and results of this are given in Section III.

(2) By a computation of the daily energy output, by the method of indirectcalorimetry.

It is clear that work such as this is necessarily different in kind from exact laboratory research. In proportion as one succeeds in gauging the infinitely varied activities of the child, one must depart from standardised conditions and give up the intention of making experiments on any given occupation facsimiles of each other. Except in studies of basal metabolism, where standard conditions have been observed as carefully as possible, no attempt has been made to circumscribe or modify the subject’s activity. The aim has been to take measurements of the cost of school life as it is actually lived, and to try to get sufficient numbers of experiments on the children of each group to strike a fair average among the variations due to chances and the personal factor.

Apparatus.

The method and apparatus are described in detail by Oathcart in the ‘ R.A.M.C. Journal,’ November, 1918 (1). For the collection of samples we have used certain modifications of the Douglas apparatus, which were approved by the Metabolism Sub-Committee of the Royal Society Food (War) Committee, in December, 1918. Our Douglas bags, of capacities varying from 60 to 130 litres, have been made of thin material, which gives greater accuracy in measuring, and is light and flexible for a child’s use. The wide-bore tap has been considerably reduced in weight. We have used face masks of the kind introduced by Mrs. Hodson for use with munition women (2). These are made, half of fight metal, half of flexible rubber, which adjusts closely to the nose. The circular valves are protected by very fight metal fittings, and the parts readily unscrew for sterilization. We have lately had a mask made with Rosling valves, and this is also satisfactory. Small alterations in the direction of the pull of the attaching elastics have greatly reduced the possibility of leaks. The advantages of the mask over the mouthpiece are considerable. The mask requires little education of a good subject, since it allows of breathing by mouth or nostrils at will, and occasions very little discomfort. The valves are silent, and the outlet tubing, passing from the cheek-level to the tap on

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370 M iss E. M. Bedale. Energy Expenditure and

the shoulder, does not interfere either with the sight or the free movements of the head. The use of a mouthpiece and noseclip would be psychologically impossible with children.

The analyses were performed on the smaller Haldane apparatus. The usual routine analyses of atmospheric air were carried out to check the accuracy of the apparatus and operator.

Some account of the school and its life is indispensable for the understanding of the experimental records. The school consists of about 100 boys and 100 girls.

Buildings.—The main building surrounds a covered quadrangle, 90 by 60 feet, which is used for gymnastics, for games on wet afternoons, and for play in all odd moments. In this building are the Hall, most of the classrooms and laboratories, and, on the upper flats, the boys’ dormitories.

The girls’ house is about 150 yards d istan t; here they sleep, but meals, classes, etc., are shared with the boys in the main building. Only for games and gymnastics do the boys and girls separate.

There are additional buildings for various handicrafts, smaller gymnasia, workshops, and music rooms. There is also a hall used for concerts and lectures, and a large library for quiet work. All buildings are warmed with hot water, and are well ventilated. The dispersion of the buildings involves considerable expenditure of energy between classes, etc., as may be seen in the assessment of the day’s output under Section I, D. This complete relaxation of five minutes between school periods seems to be beneficial, both physically and mentally.

Grounds.—As usual in a school of this type, there are large playing fields. There is also an open-air swimming bath. The grounds, altogether, cover about 90 acres, and give much freedom in the everyday life. The surrounding down- land country gives scope for long walks and expeditions, which have to be considered in computing a whole week’s energy outlay.

Life of the School.—The arrangements for the physical well-being of the children are very good ; points regarding sleep, food, and exercise will be mentioned in their context among the experimental records. The comfortable and sensible clothing of both boys and girls has an undoubted influence on

Section I.—The School.

A. Conditions of Life.

their physiological economy.




The usual games are played, and in addition, a good deal of outdoor work is done on the farm, the playing fields, and grounds generally. Handicrafts and manual work are more general and varied than is common. On the intellectual side, it is enough for the present purpose to say that about the usual proportion of boys and girls pass public examinations and enter the universities. In short, it has been possible to study a community of boys and girls who live a normal healthy life, with many interests and real zest.

The following summaries of the time table will serve to introduce the more detailed study of the school day and its energy cost.

Time Table.Summer. Winter.

7.0 Rise. 7.10 Rise.7.20 Short run and walk. 7.30 Run and walk.7.45 Breakfast. 7.45 Breakfast.8.10 Bedmaking, etc. 8.10 Bedmaking, etc.

9.0-10.45 1st and 2nd School. 9.0-10.45 1st and 2nd School.10.45-11.15 Break for lunch and outdoor 10.45-11.15 Break.

recreation. 11.15-12 3rd School.11.15-12 3rd School. 12.5-12.50 Gymnastics.

12.5-12.50 4th gymnasium or bathe 12.50 Inspection.(alternate days). 1.0 Dinner.

12.50 Inspection. 1.30-2.15 Quiet rest.1.0 Dinner. 2.30 Games or outdoor work, etc.

1.30-2.15 Quiet rest. 4.30-5.30 x\ftemoon School.2.30-3.30 Handicrafts, music, etc. 5.30 Singing.3.30-5.30 Games, gardening, etc. 6.0 Tea.

5.30 Bathe. 6.30-7.30 Evening School6.0 Tea. 7.30-8.30 Handicrafts, lectures, dancing,

6.45-8.30 Evening School. etc., on different evenings.8.45 Bed. 8.45 Bed.9.30 Lights out. 9.30 Lights out.

The younger children go to bed at 7.30

B. Subjects and Experiments.

I t was necessary to rely entirely on volunteers for the supply of subjects both in metabolism experiments and in dietary studies. The response was good, and the volunteers did all in their power to make the experiments successful. At the main school, 45 boys and 55 girls acted as subjects of respiratory observations, many of »these providing a large number of experiments on various types of activity, together with the basal metabolism; while others again were subjects only for a few experiments of special sorts. Such a voluntary system is to be preferred in almost every way, and while a few gaps and overlappings occurred, as the work aroused interest, first in one part of



the school and then in another, it is hoped that studies were obtained which are representative of most stages of adolescence.

Prolonged and detailed studies of the activity of single subjects were not generally possible; it was not desirable to interfere with the child’s life or to make the routine of experiment irksome. However, in the case of one girl, we have between 30 and 40 observations of a most reliable sort. B.R,. was an excellent subject, always ready for an experiment, but never allowing the apparatus to disturb the business she had in hand. She was 11| years old when observations began, and she continued to act as subject at intervals for four terms. The work for energy expenditure obtained from this subject amounts to a fairly complete study of the activity of a well-grown girl in the stage just before puberty.

For arriving at estimations of the energy output of boys and girls at other ages, it has seemed best to group together six to twelve more or less similar children, and to take the average of their measures and of the experiments performed on them. In this way the personal factor is reduced, and a much larger number of experiments can be made the basis of the averages.

In arranging these groups from which to extract “ typical children,” particular attention was given to getting what appeared to be the normal sort of child of each age at the school. Not only age, but physique, temperament and habits were taken into consideration. The importance of the age factor can be over-estimated; mental and muscular development are more important in determining a child’s activity; and in studying his energy metabolism (as much as in arranging his school work) these must preponderate in “ placing ” him. In a few cases, therefore, it has seemed right to overlook a small disparity of age and to place a child in the group to which, physiologically and temperamentally, he seemed properly to belong.

The groups arrived at are as follows :—(1) Boy.—Average age, 17yb years; average height, 176-1 cm.; average

weight, 61 *6 kg.Experiments on nine boys are the source of the assessment made for this

“ type.” All were well-grown and athletic, and led a full and active life; there is, however, no excess of games or sports-training.

(2) Boy.—Average age, 157b years ; average height, 164 *4 cm. ; average weight, 50 *1 kg.

The data here are drawn from nine boys, more dissimilar among themselves, both in physique and habits, than the boys of the last group. Five of them were promising athletes.

372 Miss E. M. Bedale. Energy Expenditure and




(3) Boy.—Average age, 13rV years ; average height, 158 *4 cm .; average weight, 42 *5 kg.

Seven subjects, all vigorous and well-developed.(4) Boy (under-developed).—Average age 13TV years ; average height, 152 -8

cm .; average weight, 38 -1 kg.These boys, whose average age is the same as that of Group (3), were subjects

for a considerable number of experiments. They were of poor physique and backward mental development, and the differences seemed great enough to justify a separate consideration of them. Their basal metabolism is definitely lower; but in working out their day’s expenditure, it seems that their greater excitability and restlessness brings up their total caloric output to a figure not very far short of that of the normal boys of their age.

(5) Girl.—Average age, 17tV years; average height, 166 •! cm .; average weight, 57 *6 kg.

From nine subjects, all of whom play games.(6) Girl.—Average age, 15rV years ; average height, 163 cm. ; average weight,

53 *7 kg.From seven subjects.(7) Girl.—Average age, 14TV years ; average height, 161 cm .; average weight,

49 *6 kg.From eleven subjects, of various physiques and habits.(8) Girl.—Average age, 12TV years; average height, 158 *7 cm .; average

weight, 45 -8 kg.From eleven typical subjects.I t is probably partly chance that the great majority of girls of this age now

at the school are of superior physique. The well-known fact that girls’ growth outstrips the boys’ about the time of puberty is strongly illustrated in this study. The average measurements and energy metabolism of girls of this age approximate very closely to those of the group of boys ten months older.

(9) Girl (under-developed). — Average age, 12TV years; average height,142 *2 cm. ; average weight, 32 *7 kg.

Four girls who were definitely sub-normal were among the keenest volunteers for experiment, and were accepted for purposes of comparison. All, but one in particular, were undersized, and all were backward mentally and lacking in vigour, but there seemed to be no known cause of ill-health in any case.

(10) B.R.—Age about 12 years ; height, 157 cm. ; weight, 47 *6 kg.This is the individual study already referred to. B.R. was very big and

active, and played games strenuously but without agility.



374 Miss E. M. Bed ale. Energy Expenditure and

(11) Girl.—Average age, 11A years; average height, 147 -3 cm. ; average weight, 36-7 kg.

This group is composed from studies on six girls belonging to the most junior forms of the school. Their work naturally involves less sitting still than that of older children. All the subjects were well nourished and very active.

Experimental Records.—About 800 experiments were carried out to ascertain the “ caloric cost ” of school activities. Twenty-five occupations ” were studied. These data, as explained, have to be omitted, and the difficulty arises that a general average cannot validly be drawn for the cost of an activity when the subjects are so dissimilar. Taking the cost of football for an example, it is impossible to average together results drawn from boys of 11 and 12 years with those drawn from expert players of 17 and 18. The differences depend on too many factors, and a reduction to expenditure per square metre of surface area is simply misleading. As already explained, the only satisfactory method of averaging was found to be the composition of “ typical boys and girls ” of various ages. The average costs of the school occupations for these ten “ typical children ” have been calculated from experiments performed on the individuals composing each separate group, and these averages are given in Tables II and III. These tables, and those for the cost of the school day, which follow them, must needs appear arbitrary, as they cannot be referred back to their sources in the actual experimental data. I t may be said that efforts were made to get a fair number of experiments representative of each group of children in each of their chief occupations, and that special attention was given to all those activities which, either because of their strenuous character or because of their long duration, bulk largest in the adolescent’s budget of energy expenditure. The whole of the material thus gathered is summarised very briefly in Tables II and III.

Basal Metabolism of Children.—The determinations of basal metabolism were made upon the subjects in bed before the calling bell, at 6.45 a.m. This method was made necessary by laboratory conditions, and by the understanding that the school routine should not be interfered with. But it was also thought that such a procedure has definite advantages of its own, since the subjects were warm and quiescent, and muscular relaxation was more complete than can easily be achieved on a laboratory couch. In most cases the children were hardly disturbed by the fixing of the mask, and often dozed during the collection of the sample. A proportion of these experiments, however, gave anomalous results—either abnormally low ventilation rate or respiratory quotient, or both—occurring generally with the observer’s note



Food Requirements of Children at School.375

that the subject was apparently sleeping. I t was impossible to trace any technical error in these experiments and they would seem to be instances of the known “ depressed metabolism during sleep.” These experiments are excludedfrom Table I.

36 observations on boys and 51 on girls were obtained. The summary of these is here given in Table I ; the data from the Junior School (Section II) are, for convenience, given in the same table.

The following points may be noted :—(1) The figure obtained for boys of 14 is not representative ; neither subject

was up to standard in physique and vitality. The same is true in a lesser degree of the boy of 12 and the girl of 14. These experiments were rather difficult to arrange, and it was not always possible to get the best subjects for them.

(2) The high basal heat production of big boys, over 16, corresponds with their high food-intake and active life.

(3) In the case of girls, the basal metabolism per square metre of body surface falls away in an almost straight line from the age of 11, at which it is very high and almost identical with that of the boy of the same age.

Table I.—Basal Metabolism.—Boys and Girls.—Averages.

Years. Calories per hour.

Calories per hour per

square metre.

Basal heat production in 24 hours (calories).

Number of individuals.

Number of studies.

Boys— ....18 .... 80-97 46-27 1,943 1 216 .... 73-12 44-43 1,755 2 515 .... 60-84 40-13 1,460 3 014 .... 45-66 35-16 1,096 2 513 .... 59-13 43-18 1,419 4 612 .... 47-50 34-93 1,140 1 211 56-38 48-10 1,353 4 68 .... 40-12 40-39 963 3 4

Girls—17 .... 56-19 31-83 1,349 2 516 .... 56-81 36-96 1,363 5 815 .... 60-67 38-34 1,456 4 414 .... 51-18 34-18 1,228 1 113 .... 61-60 43-08 1,478 3 312 .... 58-41 43-89 1,402 10 1111 .... 62-40 47-73 1,498 3 1110 .... 41-15 40-90 988 2 39 .... 45-25 42-62 1,086 2 47 .... 47-55 49-50 1,141 2 2




C. Assessment of the Day's Energy Expenditure.

The computation of the day’s expenditure is rendered fairly easy by the time table, which in main outline is much the same for six days of the week.

In addition to this, several of the subjects kept accurate notes of how they spent the day, especially describing the kind and amount of their activity in odd moments. One of these diaries is given in full as the child (B.R.) presented it, with the caloric cost worked out from some 40 experiments on herself alone. (Table IV.) I t serves to show in rather more detail how all the “ typical days ” have been calculated.

Familiarity with the life of the children has made it possible to subdivide composite items, such as “ getting-up,” “ break,” “ bathe,” etc., into spells of so many minutes at one rate, so many at another, thereby greatly reducing the error. All this cannot be shown in the Tables IV to XII, the values of which, therefore, will not always appear to correspond exactly with the summary of values for “ typical ” children given in Table II.

An examination of Table II and of Table III (its counterpart, expressed in calories per square metre surface area) shows that, for some occupations, the average expenditure of the various groups do not present regular curves. It must be remembered that these averages are drawn from a comparatively small number of experiments, about 800; that the number of experiments on any given occupation varies considerably from group to group; and that no attempt was made to standardise the conditions, so that the individual habits of the subjects composing each “ typical ” child are, to some extent, reflected in these average values.

In these circumstances, it seems best to give the irregular values as they stand, rather than to attempt any smoothing of the curves.” On the whole, the anomalies are not so many nor so marked as was perhaps to be expected, considering the small numbers and the importance of the personal factor, accentuated by the degree of individual freedom which obtains at the school.

For certain items of the day’s work which do not lend themselves to direct experiment, e.g. the morning cold plunge, we have no data for several groups. In these cases, calculations based on the few available data are made to serve.

The following points stand out from Tables II and I I I :—

(1) The very high values for boys about 17 years.(2) In girls, the rise in basal metabolism per square metre, for younger

subjects, especially in the two pre-puberty studies, B.R. 12 years, and “ typical ” girl of llxV years.




(3) The similarity of the values given by the normal, well-developed boy of 13* and girl of 1 2* years. The averages are drawn in the first case from experiments on seven boys, all good specimens ; the “ girl ” is the average of eleven subjects, quite representative of their age at the school, but very conspicuously larger than, for example, the girls of the same age at the local village school.

Table II.—Average Values used in Assessing “ Typical Days of TypicalChildren.”

Boys. Girls.

Average height (cm.) 1761 164-4 158-4 152-8 166-1 163-0 161-0 158-7 142-2 157-0 147-3Average weight (kg.) . . . . 61-6 50-1 42-5 38-1 57-6 53-7 49-6 45-8 32-7 47-6 36-7Average surface area . . . . 1-75 1-53 1-38 1-29 1-63 1-55 1-50 1-44 1-13 1-43 1-23

Average age . . . . 1 7* 1 6 * 13^ n s * 1 7 * 15t°2 1 4 * 1 2 * *12* B.R.about

12

1 1 *

Basal per hour .... 74-69 62-52 53-11 49-61 56-49 56-41 56-84 53-72 40-49 59-11 55-96Basal per minute . . . . 1-24 1-04 0-89 0-83 0-94 0-94 0-95 0-90 0-67 0-99 0-93Sitting per minute . . . . 1-86 1-59 1-39 1-25 1-57 1-55 1-42 1-43 1-44 1-47 1-32Standing per minute . . . . 2-09 1-89 1-63 1-49 1-64 1-69 1-62 1-76 1-40 1-81 1-49Walking per minute . . . . 3-76 3-85 3-97 3-14 4-03 3-70 3-61 3-97 3-02 3-09 2-99Running _ 12-8 8-01 7-06 6-64 10-99 6-52 7-70 6-66 5-54 6-17 4-93Football............... . . . . 11-44 11-20 5-60 5-68 — — — — — — —

Lacrosse............... . . . . — — — — 7-08 6-55 5-40 5-62 — 6-18 —

Cricket, etc........... . . . . — — 3-19 2-50 — — 3-44 3-17 2-41 3-95 2-78Gymnastics . . . . 5-25 4-42 3-49 3-06 4-80 4-51 3-36 3-50 2-76 4-31 3-43Quad, games — 4-77 5-08 4-75 — — — 4-36 — — 4-37Outdoor work, heavy . . . . 9-34 5-06 — — — • — 6-0 — — — —

Outdoor work, light 7-22 — — — — 3-59 2-64 — ' — — —

Outdoor work, summer — 5-42 — — — 5-08 4-64 4-93 — — —

Gardening . . . . — 3-66 4-02 3-22 — 3-71 3-98 — — — —

Workshop — 3-17 1-88 1-29Swim ............... — 9-07 — — 8-07 6-64 6-83 6-60 5-80 6-71 6-04

fCold bath 7-0 6-01 5-38 5-03 5-5 5-22 5-06 5-50 3-16 4-44 3-98fDressing .... . . . . 3-0 2-8 2-4 2-41 2-8 2-66 2-43 2-39 2-01 2-22 2-18t Bedmaking, etc. . . . . 3-7 3-7 3-31 3-10 3-6 3-20 3-10 3-14 2-7 3-11 2-68

Siesta ...........................Odds and ends—waiting

1-56 1-59 1-54 1-33 1-08 1-43 1-28 1-41 0-79 1-36 1-19

about .... 2-76 2-75 2-16 2-14 2-39 2-03 2-35 2-26 1-85 2-50 2-02Piano practice .... — — — 1-31 — 1-19 1-75 1-66 0-95 — —

Violin practice .... . . . . — 1-92Dancing .... 6-OOf — — — 5-40 6-40 5-82 — — — —

Light handicrafts . . . . 1-60 1-41 1-49

# Under-developed.f No data for some groups; values calculated.

The “ typical days ” assessed in Tables IV to X II were arrived at after very careful consideration and discussion of each case separately, the writer’s observations being checked and supplemented by members of the school staff.




It is believed that they do fairly represent the “ average ” school day of the respective groups of children. But naturally the energy expenditure is liable to variation with the day’s time-table, and it would have been possible in every case to assess an equally “ probable ” day at an expenditure of 50 calories more or less than the figures here given. In the case of some groups at least, the error is probably not less than 150 calories. Comparison with the averages of observations on Food Consumption suggests that the activity has been slightly underestimated in some cases (Section IY).

Table III.—Being Tabic II expressed in Calories per Square Metre of SurfaceArea.

Boys. Girls.!

Average height (cm.) ... 176-1 164-4 158-4 152-8 166-1 163-0 161-0 158-7 142-2 157-0 147-3Average weight (kg.) .... 61 • 6 50-1 42-5 38-1 57-6 53-7 49-6 45-8 32-7 47-6 36-7Average surface area .... 1-75 1-53 1-38 1-29 1-63 1-55 1-50 1-44 1 -13 1-43 1-23

B.R.Average age 1 7 * 15t\ *13* 1 7 * 15^ 1 4* 12y92 *12* about

12i i *

Calo•ries per square metre of surface area.

Basal per hour .... 42-68 40-86 38-49 38-45 34-65 36-39 37-89 37-31 35-83 41-33 45-50Basal per minute 0-71 0-68 0-64 0-64 0-58 0-61 0-63 0-62 0-60 0-69 0-76Sitting per minute 1 0 6 1-04 1-01 0-97 0-96 1-00 0-95 0-99 1-27 1-03 1-07Standing per minute .... 1-19 1-23 1-18 1-16 1-01 1-09 1-08 1-22 1-24 1-27 1-21Walking per minute 2-15 2-52 2-88 2-43 2-47 2-39 2-41 2-76 2-67 2-16 2-34Running........................... 7-31 6-24 5-12 5-15 6-74 4-21 5-13 4-63 4-90 4-31 4-01Football .... 6-54 7-32 4-06 4-40 — — — — — — —Lacrosse .... — _ — _ 4-34 4-23 3-60 3-90 — 4-32 —Cricket, etc....................... — — 2-31 1-94 — — 2-29 2-20 2-13 2-76 2-26Gymnastics ............... 3-0 2-53 2-53 2-37 2-94 2-91 2-24 2-43 2-44 3-01 2-79Quad, games — 3-12 3-68 — — — — 3-03 — — 3-55Outdoor work, heavy .... 5-34 3-31 — . — — — 4-00 — — — —Outdoor work, light 4-13 — — — — 2-32 1-76 — — — —Outdoor work, summer — 3-54 — — — 3-28 3-09 3-42 — — —Gardening ............... — 2-39 2-91 2-50 — 2-39 2-65 — — — —Workshop ............... — 2-07 1-36 1-00 — — — — — — —Swim ........................... _ 5-93 _ __ 4-95 4-28 4-55 4-80 5-13 4-69 4-91

tCold bath ............... 3-78 3-93 3-90 3-90 3-37 3-37 3-37 3-82 2*80 3-10 3-24‘(•Dressing........................... 1-71 1-83 1-74 1-87 1-72 1-72 1-62 1-66 1-79 1-55 1-77f Bedmaking, etc. 2 11 2-42 2-40 2-40 2-21 2-06 2-07 2-18 2-39 2-17 2-18Siesta ........................... 0-89 1-09 1-12 1-03 0-66 0-92 0-85 0-98 0-70 0-95 0-97Odds and ends—waiting

about .... 1-58 1-80 1-57 1-66 1-47 1-31 1-57 1-57 1-64 1-75 1-64Piano practice ............... _ — — - 1-02 — 0-77 1-17 1-15 0-84 — —Violin practice............... — 1-25 — — — — — — — — —

Dancing........................... 3-43 — — — 3-31 4-13 3-88 — — — —

Light handicrafts — — — — ----- - * 1-11 1-25 1-04

* Under-developed.f No data for some groups; values calculated.



Food Requirements o f Children at School, 379

Table IV.—A Winter-term Day of a Girl in a Junior Form.—B.R., age 12 years.Height, 157 cm. Weight, 47 -6 kg. Surface area, 1 -43 square metres.

8.30 p.m. i r In bed— Calories.to y - 4 6 hours at basal rate = 62*43 per hour .... 374-58

7 a.m. j i 4*5 hours at basal rate + 15 per cent. = 71-79 per hour 323-06

N ig h t............. .............. 697-64

a.m. mins.7.0 10 Sitting talking in bed ................................................... 14-66

3 Cold bath and running to i t ................................................... 13-210 Dressing ............................................................................ 22-235 Going down, w aiting............... 12-03 Hard run ............................................................................ 18-518 Walking 24-726 Waiting about, at 2 • 5 calories ............... 15-0

7.45 25 Breakfast 42-148.10 20 Bedmaking, etc. ............................................................... 62-2

20 Mending clothes, standing ................................................... 36-32 Running over to school 12-347 In form room ........................................................................... 7-69

Before school 280-99

9.0 5 Walking over, changing for gymnastics ........................... 13-2545 Gymnasium exercises, vaulting, bar-work 193-86

5 Short break .............. . ................................................... 13-2540 Class, sitting 58-64

10.45 30 Break, 15 'stroll 46-35Break, 15' ball games............................................................... 61-99

11.15 30 Class, sitting ........................................................................... 43-985 Short break ........................................................................... 13-25

25 Class, sitting ........................................................................... 36-655 Short break 12-00

p.m. 30 Class, light handicraft ................................................... 48-2412.50 6 44 Tidying up ” at 2*2 calories 13-32

4 Standing, inspection .... 7-26

Morning ............... 562-04

1.0 30 D inner....................................................................................... 50-553 Walking over to girls’ house ....................................... 9-274 “ Odds and ends ” ....................................... ............... 10-004 S ittin g ....................................................................................... 5-84

35 Siesta—lying quiet, reading................................................... 47-615 Changing 44 in an awful hurry ” ....................................... 44-461* 46 Running over, top speed ” ....................................... 12-47

2.30 50 Modelling in studio : stand fairly still, fine w'Ork............... 87-4510 Eating bun, strolling to fields 27-00

3.30 60 Lacrosse, 44 fairly energetic ” ....................................... 370-804.30 30 Changing, with warm spray bath ....................................... 80-00

20 Free time—ball games ........................... ............... 79-0010 44 Odds and ends ” ............................................................... 25-0025 Singing, sitting and standing ....................................... 48-00

5 Waiting about 12-5

Afternoon ............... 909-94




Table IY.—continued.

p.m.6.0

mins.30 Tea .......................................................................................

Calories.50-55

10 In quadrangle........................................................................... 25-0050 In Form room at 1 • 8 calories 90-00

7.30 — Going to bed, i.e. 5' walking about...................................... 12-00

8.0 to 8.30 30

5' “ ragging ” .......................................20' undressing, etc....................................

Lying in bed—not settled ...................................................

25-0039- 0840- 92

Evening ............... 282-47

Summary.

NightBefore school Morning .... Afternoon Evening ....

Calories.697-64280-99662-04909-94282-47

Total .... 2,733-08

Table Y.—Cost of the School Day.—Boy, 17 A years. Average height, 176 -1 cm. Average weight, 61 *6 kg. Surface area, 1 *75 square metres. AWinter-term Day. From nine subjects.

Calories.10 p.m. 9 hours’ sleep—5 hours at basal rate ....................................... \ 717-02to 4 hours at basal rate + 1 5 per cent................... f

7 a.m.a.m.7.0 Getting up, cold bath .......................................................................... 67-877.20 Run, walk, etc............................................................................................... 124-927.45 Breakfast ............... ........................................ ........................... 53-398.10 Bedmaking, etc........................................................;.................................... 168-50


9 a.m. 2 periods sitting .... .... .... .... .... ............... 157-85to 1 period in laboratory 101-24

l p.m. 1 period gymnastics .......................................................................... 236-163 short breaks between classes .... .... ............... ............... 46-4230' long break—football practice .... ............... 164-01Inspection .... .... .............................................................. 24-27

Morning ............... 729-95

p.m.1.0 Dinner .................................................................................................. 64-06

1.30 to 2.30 Siesta and ch an ge...................................................................................... 192-082.30 Football .... .... .... .... ............... 697-43.40 Change, etc. 112-74.0 Class.............................................................................................................. 194-025.30 Singing .................................................................................................. 47-95

Afternoon 1 308-21



Food Requirements o f Children at , 381

Table V.—continued.p.m.6.0 Tea ................................................................................................................

Calories.67*20

6.4010' in Quadrangle........................................................................................Class.................................................... ....................................................

30*00102*14

7.35 Dancing .................................................................................................... 330*098.30 to 9.30 Getting to bed, etc......................................................................................... 158*309.30 to 10.0 Settling into s le e p ........................................................................................ 42*95

Evening ...............Day’s Total ........................... 3,900-54 calories.

730*68

Table VI.—Cost of the School Day.—Boy, 15tV years. Average height, 164 *4 cm. Average weight, 50*1 kg. Surface area, 1*53 square metres. ASummer-term Day. From nine subjects.

Calories.10 p.m. to 9 hours’ sleep—5 hours at basal rate .... .... .... .... \ 600*197 a.m. 4 hours at basal rate + 15 per cent....... .... I

a.m.7.0 to 7.20 Getting up, cold bath ............... .... .... .... .... .... 59*08

7.20 Run, walk, etc................................... _ .... .... .... _ 116*547.45 Breakfast ....................................... _ .... .... .... .... 49*698.10 Bedmaking, etc.................................. .... ............... .... .... 162*58

Before school. .. .... 387*89

9 a.m. to 2 periods in class, sitting ............... 135*151 p.m. 1 period in laboratory, standing .... . . . . . . . . 85*05

1 period bathe . . . . . . . . . . . . 250*6015' short breaks between classes .... . . . . _ . . . . 45*9930' break, recreation out of doors . . . . 113*70Inspection ....................................... ............... .... .... 27*5

Morning .... .... 657*99

p.m.1.0 Dinner ....................................... .... .... .... .... .... 52*47

Siesta and ch an ge........................... .... .... .... .... 131*21Workshop ....................................... .... _ .... 195*4010' free ....................................... .... .... .... .... 27*5Haymaking....................................... .... .... _ _ 440*0Bathe ....................................... .... ............. .... .... 157*2

Afternoon .... .... 1,003*78

6.0 Tea ................................................... 45*7110' free ....................................... .... .... 27*550' sitting in c la s s ........................... .... .... _ .... 81*55' break ................ ............... _ _ .... 15*0

8.30 to 9.309.30 to 10.0

50' class ....................................... 81*5Going to bed, etc...................In bed .... ...........................

.... .... .... 159*136*0

Evening .... .... 446*41

Day’s Total ............... .... 3,096-26 calories.




Table VII.—Cost of tbe School Day. Boys of 13^ years. Winter Term.

Well grown and normally developed.

7 subjects.Average age 13T\ years.

Average height 158*4 cm. Average weight 42*5 kg. Surface area 1 • 38 sq.m.

Poor physique, underdeveloped. excitable and

active.

3 subjects.Average age 13^ years. Average height 152 • 8 cm. Average weight 38*1 kg. Surface area 1*29 sq. m.

Calories. Calories.10 p.m. to 5 hours at basal rate '1 8.30 p.m.

7 a.m. 4 hours at basal rate -f* > 509-86 -7 a.m. 561*8315 per cent. J

a.m.7.0 Getting up, cold bath .... 50-45 48-64

Run, walk, etc....... 103-22 82-457.45 Breakfast........................... 43-44 89-068.10 Bedmaking, etc.................. 140-31 130-10

337-42 300*25 Before school

9 a.m. to 3 periods in class.... 191-50 173-31 p.m. 15' short breaks............... 45-51 41-10

30' long break, footballpractice.... 125-45 118-60

** Gymnastics ............... 157-05 135-70Inspection 21-6 19-21

541-11 487-91 Morning

p.M.1.0 Dinner 47-95 43-13

1.30 to 2.30 Siesta and change 120-55 109-102.30 to 3.30 Football .... 336-00 340-8

Change ........................... 89-85 81-74.0 to 5.30 Workshop.... ............... 179-65 121-355.30 to 6.0 Singing ' ........................... 56-30 41-10

830-30 737-18 Afternoon

6.0 Tea ........................... 39-96 35-9410' play in quadrangle .... 30-00 27-9350' class ........................... 71-00 62-50

7.30 * 50' indoor recreation 100-00 To bed 72-3010'free ........................... 21-6 8-8.30

8.30 Getting to bed ............... 163-40 in bed 33-09.30 to 10 In bed ........................... 37-00

462-96 231-67 Evening

Day’s Totals............... 2,681-65 calories. 2,318-84 calories.




Table VIII.—Cost of the School Day. Girl of 17A years. Average height, 166 -1 cm. Average weight, 57 *6 kg. Surface area, 1 -63 square metres. A Winter-term Day. From nine subjects.

10 p.m. to 7 a.m.

9 hours’ sleep—5 hours at basal rate .... .... .... ....4 hours at basal rate + 15 per cent....... .... J

Calories.542-30

a.m.7.0 to 7.20 Getting up, cold bath 57-04

7.20 Short run, walk, etc. 100-737.45 Breakfast *... 45-118.10 Bedmaking, etc.................................................................................. 179-73


9.0 a.m. to 2 periods in class .... 133-191 p.m. 1 period in laboratory ............... 72-34

1 period in gymnasium 216-453 short breaks ........................ . 46-11Long break, lacrosse practice .... .................................................. 179-70Inspection .................................................................................................... 16-40

Morning 664-19

p.m.1.0 Dinner ............... .... .... .... ........................... 51-71

Siesta, change ....................................................................................... 130-892.30 Lacrosse ........................... ............... 506-403.30 Changing, etc. ....................................................................................... 123-21

4.0 to 5.30 Class and preparation 141-21Singing ....................................... 41-67Prefect’s jobs, 10' 19-12

Afternoon 1014-21

6.0 Tea ............................................................................................................... 48-6510' prefects’ jobs 30-00Piano practice—Preparation .... ............... ............... 99-55

. 7.40 Dancing 256-158.30 to 9.30 Going to bed, etc....... 144-059.30 to 10.0 Settling into sleep (siesta rate) ........................... ........................... 32-42

610-83

Day’s Total .... .... .... 3,214* 14 calories.

2 FVOL. XCIV.— B.




Table IX.—Cost of the School Day.—Girl, 15rV years. Average height, 163 cm. Average weight, 53 -7 kg. Surface area, 1 -55 square metres. A Summer-term Day. From seven subjects.

10 p.m. to 7 a.m.

9 hours’ sleep—5 hours at basal rate .... .... .... .... ^5 hours at basal rate + 15 per cent....... .... C

Calories.541-59

a.m.7.0 Getting up, cold bath 51-557.20 Run, walk, etc........... .... .... .... ........................... 82-267.45 Breakfast 42-638.10 Bedmaking, etc...................... .... .... .... ............ .............. 149-87


9 a.m. to 2 periods in class .... .... .... .... .... .... ............... 131-751 p.m. 1 period in laboratory . .. .... .... .... ........................... 72-25

1 period bathe .... .... .... .... .... .... ............... 202-95For three short breaks 43-44Long break, with 20' tennis .... .... .... .... ............... 112-30Inspection .................................................................................................. 18-26

Morning ............... 580-95

p.m.1.0 Dinner 53-48

Siesta, change .... .... .... .... .... ............... 118-981 period in class ...................................................................................... 77-5

3.20 to 5.0 Haymaking .... .... .... ... .... .... .... ............... 455-905.0 Bathe .... .... .... .... .... .... .... ...t 135-885.30 Free time—tennis, 25' .... .... .... .... ........................... 135-3

Afternoon ............... 977-04

6.0 Tea .... .... .... .... .... .... .... .... ............... 42-6310' free time.... .... .... .... .... .... ........................... 20-3

6.40 to 8.30 Class, preparation or handicraft .... 192-08.30 to 9.30 Getting to bed, etc.... 111-159.30 to 10.0 In bed—settling to sleep .... 36-0

Evening ............... 402-08

Day’s Total ........................... 2,827-97 calories.




Table X.—Cost of the School Day.—Girl, 14T6v years. Average height, 161 cm. Average weight, 49 *6 kg. Surface area, 1 -50 square metres. A Winter-term Day. From eleven subjects.

10 p.m. to 7 a.m.

9 hours’ sleep—5 hours at basal rate .... .... .... .... \4 hours at basal rate + 1 5 per cent....... .... J

Calories.545-66

a.m.7.0 Getting up, cold bath 50-967.20 Run, stroll, etc........... 86-287.45 Breakfast 40-838.10 Bedmaking, etc.......... 133-04


9 a.m. to 3 school periods 189-601 p.m. 1 period gymnastics 134-40

3 short breaks ....................................................................................... 42-2130' break, with 15' lacrosse practice 134-60Inspection .... 16-00

Morning 516-82

p.m.1.0 Dinner ........................................................................................ 48-991.30 Siesta and change .... 108-07

2.30 to 3.30 Gardening .... 232-45Changing, etc. 47-8090' class and preparation .... 145-97

5.30 Singing 56-55i

Afternoon ............... 639-83i

6.0 Tea .................................... . ............................................................... 40-8210' Quadrangle games 43-6045' piano practice .... 88-05

7.25 60' dancing .... 266-48.30 to 9.30 Getting to bed .... .... ............... ............... 116-559.30 to 10.0 Settling into sleep .... 36-00

Evening 591-42

Day’s Total ........................... 2,605-77 calories.

2 f 2




Table XI.—Cost of the School Day. Girls of 12TV years. A Summer-termDay.

Well grown and normal.

Age 12t\- years.Average height 158*7 cm. Average weight 45*8 kg. Surface area 1-44 sq.m. From 11 subjects.

Small and underdeveloped.

Average age 12T9* years. Average height 142*2 cm. Average weight 32*7 kg. Surface area 1*13 sq.m. From 4 subjects.

9 p.m. to 10 hours’ sleep— Calories. Calories.7 a.m. 5 hours at basal rate

5 hours at basal rate > 577-49 435-27+ 15 per cent. J

a.m.7.0 Getting up, cold bath .... 51-55 47-767.20 Short run, and stroll 87-32 69-127.45 Breakfast........................... 41-11 38-508.10 Bedmaking, etc.................. 140-02 124-04

320-0 279*42 Before school

9 a.m. to 2 class periods 151-95 122-41 p.m. Light handicrafts 90-0 63-45

Bathe ............... 164-25 139-233 short breaks ............... 46-29 35-58Long break, out of doors 110-26 74-4010' inspection ............... 20-50 16-70

583-35 451*76 Morning

p.m.1.0 Dinner ............... 49-34 49-341.30 Siesta, change ............... 121*89 89-802.30 4 5 'class ............... 80*44 64-35

15' break .... 33*90 30-1530' singing ............... 80*44 64-00

4.0 Cricket ........................... 285*3 216-95.30 Short bathe 136*75 115-50

!788-06 630*04 Afternoon

p.m.6.0 Tea ........................... 41-11 41-11

Free time—games 200-95 153-107.30 Going to bed ............... 71-70 60-3

8.0 to 9.0 In bed, not asleep 84-6 47-4

398-36 302-91 Evening

Totals............... 2,667-26 calories. 2,099*94 calories.




Table X II.—Cost of the School Day. Girl, 1 lyV years. Average height, 147 -3 cm. Average weight, 36 *7 kg. Surface area, 1 *23 square metres.A Summer-term Day. From six subjects.

9 p.m. to 7 a.m.

10 hours’ sleep—5 hours at basal rate ............... .... .. . \5 hours at basal rate + 1 5 per cent..... .... /

Calories.601-57

a.m.7.0 Getting up, cold bath .... .... ................................................... 52-627.20 Run, and play 70-797.45 Breakfast ............... ................................................. .......................... 38-06

Bedmaking, etc.............................................................................................. 134-2


9.0 a.m. to 2 classes ........................... .... ............... .... ............... 90-01.0 p.m. 10' breaks ........................................................................................ 25-0

30 'nature study, out of doors 89-0730' break, recreation, games 80-045' class 60-0Bathe .... ............... .... ............... ........................... 220-0Inspection ... 10-0

Morning 574-07

p.m.1.0 Dinner .................................................................................................... 45-5

Siesta and change . .. 104-45School .................................................................................................... 100-0Free time 50-0

4.0 Singing ........................... .............................................................. 44-74.30 Cricket 166-85.30 Bathe 142-38

Afternoon ............... 653-83

6.0 Tea ............................................................................................................... 37-95Free games in garden 174-15

7.30 Going to bed ............... ............................................................... 75-48.0 to 9.0 In bed, not asleep .... 70-0

Evening 357-50

Total ........................... 2,482-64 calories.

Summary of Section 1.As a result of a number of measurements of the energy output of boys and

girls of various ages, at all types of occupations, it is possible to estimate the probable heat-production in a typical school day as follows :—




Table XIII.

— —Total heat production. 24 hours.

( i ) Boy .......................... 17* yearsCalories.

3,901(2) „ ........................... 15 A >. ................................................... 3,096(3) „ ........................... 1 3 * 99 2,682W „ ........................... 1 3* ,, under-developed ........................... 2,319(5) Girl ........................... 1 7* years ................................................... 3,214(6) „ ........................... 1 5 * 99 2,828(7) „ ........................... 14* ,, .... .... .... 2,606(8) „ ............... 1 2 * „ ....................................... 2,667(9) „ ........................... 1 2* ,, under-developed ........................... 2,100

(10) B.R.............................. 12 years (an individual study) .... 2,733(11) Girl ........................... 11* years ................................................... 2,483

Section II.—The J unior H ouse.

A. Conditions of Life.

The buildings of the Junior House are about 600 yards from the school. They consist of one large house, with a wing for the Montessori School, and various workshops and such out-buildings.

There are about thirty boarders, boys and girls, and a variable number of day boarders. The children studied are nearly all from eight to twelve years old ; very few observations could be taken on children from three to seven years belonging to the Montessori School.

As in the school proper, arrangements for physical well-being are carefully thought out. This is not to say that all the subjects are of optimum health and development. I t is believed, however, that none of the children studied had any serious defect in health, and all were living the normal active life of the school.

The hours of sleep are long, the younger children going to bed at 6 p.m., and the eldest being in bed by 8 p.m. The dormitories are airy, and are warmed with hot-water pipes in winter ; only four children sleep in each room. The food is simple and abundant. The clothing is loose and comfortable, so that movement is as little as possible restricted by i t ; but that the restriction is not negligible is obvious to anyone who watches children at the swimming- baths, or even when shoes and stockings are discarded in summer.

The educational method at the Junior House is a considerable departure from the ways of preparatory schools. There is no time table. The children choose their own occupations and remain at them as long as they please.



Handicrafts or activities out of doors fill up much of the day. The evening, after tea, is generally a quiet time of reading; more formal lessons, especially for the older children, may occur on demand at any time of the day.

On the problem of measuring the energy expenditure of young children, “ The Food Requirements of Man ” may be quoted : “ The energy output of children is probably very large in proportion to their size. I t is, however, extremely difficult to measure, since it is not directed to any particular end, and will therefore cease for a time during any experiment in which an attempt is made to measure its caloric value.” The first statement is amply borne out by the experiments here recorded. The rest, perhaps, needs modification ; for the child himself there is, or should be, a “ particular end ” in his occupations. I t is necessary to see the child’s playwork from his own point of view ; it is then often possible to measure the physiological cost of the activity without checking it. I have found that children between eight and twelve, wearing the Douglas apparatus, will carry on their affairs with a complete unconcern which is comparatively rare among adolescents and adults. I t is necessary, of course, that the apparatus and operator should be familiar to them. I t may be said that the boys, for the most part, were the better subjects, and that engrossing business in the workshop afforded the best opportunities for studying the children.

The total number of experiments is unfortunately small, about 140. A good deal of time was spent in drawing blanks to get the children accustomed to the apparatus ; the a voidance of any suggestion of anxiety or haste was essential to success.

I believe that much more work might usefully be done on the same lines, and that it could be extended to younger children. A few observations taken on five-year-olds were very promising, but time and circumstances did not permit of any real work with these small children.

B. Subjects and Experiments.As in the main school, it was found most convenient to group together several

children of similar age and physique, in order to arrive at something like the “ average child.” In the Junior House, four such groups were studied :—

(1) Boy.—Average age, 101! years ; average height, 142 *2 cm .; average weight, 32 *4 kg.

The averages are drawn from experiments on five boys, all well-grown and active. These boys spent a great part of every day either working out of doors or in the workshop.

Food Requirements o f Children at School. 389 on August 21, 2018http://rspb.royalsocietypublishing.org/Downloaded from


(2) Boy.—Average age, 8XV years'; average height, 127-1 cm. ; average weight, 25 -5 kg.

Seven boys were subjects for this group. They were dissimilar in tastes and habits, some spending a good deal of time indoors at such occupations as weaving, modelling and cooking, while other were regular denizens of the workshop. Those who were newcomers to the school changed their occupations so frequently that it was difficult to ascertain their day’s programme.

(3) Girl.—Average age, 10H years ; average height, 143 -0 cm .; average weight, 32 -5 kg.

The five girls of this group spent a greater proportion of their time in the schoolroom than any other group of children in the school; but their life was nevertheless considerably more active than that of girls of the same age at the main school. (See Table XII, Section I.)

(4) Girl.—Average age, 9A years ; average height, 134 *3 cm. ; averageweight, 28 -2 kg.

From five children. Like the younger boys, these children changed their occupations greatly from day to day, and while they were keen subjects, so that it was not difficult to gauge the cost of the several types of activity, it was difficult to say with any accuracy how many hours or minutes they might be expected to spend in this manner. That is to say, day could easily be assessed, but a typical day was non-existent.

Experiments.—The experimental data fall under the following headings : basal metabolism, workshop, gardening and similar outdoor occupations, games, walking and running, schoolroom, weaving, care of animals. A summary of the results is given in Table XIY, showing how the values in Table XV, the assessment of the day’s cost, are reached.

C. Estimation of a Day’s Energy Expenditure.

The compilation of a “ typical day ” for the children of the Junior House has proved a difficult task. The manner of living resembles more nearly that of children home for the holidays in a big country house, than that of a school where time-table methods are adhered to. Whereas in the main school it was possible to estimate with some accuracy the probable activities of the children at any moment of the day, it is here only possible to make a general inclusive assessment.

The estimates summarised in Tables XIY and XV were arrived at by watching the habits of the four groups of children over several weeks. The error due





to wrong apportioning of time may well be + 10 per cent., and, especially with the younger groups of boys and girls, is probably greater.

Comparison with the observed Food Consumption (Section IV) seems to suggest that the children’s activity has been considerably underestimated.

Table XIV.—Average Costs of Occupations.—Junior School.

Boy io n - Boy 8rV Girl 10n- Girl 9 * .

Basal per hourCalories.56-38

Calories.40-12

Calories.50-76

Calories.41-97

Workshop per minute 2-41 1-66 2-61 —

Gardening, etc........ 3-50 2-44 3-09 2-10Games 3-97 3-21 3-52 2-96Walking — — 2-41 2-19Running (hard) .... 7-54 7-30 — —Schoolroom 0-93 1-02 1-35 0-96Weaving .... — 1-17 1-81 1-16Care of animals ....

~ *

1-68 2-28 1-98

Table XV.—Junior House.—Estimate of Day’s Energy Expenditure.—Boys.

Boy of 1st Group.—Average age, 1011 years. Average height, 142’2 cm. Average weight, 32 -4 kg. Surface area, 1 *14 square metres.

11 hours in bed (6 hours at basal rate and 5 hours at basal rate + 15 per cent.)2£ hours meals, getting up, going to bed, etc........... .... .... ..............2 hours in schoolrooms—quiet 5 hours out of doors—various work in garden 2£ hours in workshop 1 hour active game—football

Calories.656-47350-00150-0927-0361-5250-0

2,694-97

Boy of 2nd Group.—Average age, 8TV years. Average height, 127 *1 cm. Average weight, 25 -5 kg. Surface area, 0 -96 square metres.

12 hours in bed (6 hours at basal rate and 6 hours at basal rate-4-15 per cent.) hours meals, getting up, going to bed, etc.

2 hours in schoolrooms3 hours in workshops Running about3 hours various activities in garden. ..1 hour football............................................................... ......................................1 hour free play—strenuous...

Calories.537-55315-0190-0298-8

80-0439-2230-0100-0

2,190-55




Girl of 1st Group.—Average age, 11-rf years. Average height, 143 cm. Average weight, 32 -5 kg. Surface area, 1 *14 square metres.

Calories.11 hours in bed (6 hours at basal rate, 5 hours at basal rate + 1 5 per cent.).... 656-42£ hours meals, getting up, going to bed .............................................................. 325-03 hours in schoolrooms 210-63 hours out of doors 556-21 hour workshop 156-41 hour weaving 90-61 hour care of animals 118-61 hour football 243-0| hour walking about 72-3

2,429-3

Girl of 2nd Group.—Average age, 9A years. Average height, 134*3 cm. Average weight, 28 -2 kg. Surface area, 1 -03 square metres.

Calories.12 hours in bed (6 hours at basal rate, 6 at basal rate + 1 5 per cent.) 541-42 \ hours meals, getting up, going to b e d .................................................. 315-02 hours in schoolrooms 140-41 hour weaving 90-63 hours gardening, etc. 450-6\ hour with animals .... 85-03 hours free play out of doors .......................................................................... 600-0

2,223-0

Summary of Section II .

The daily energy expenditure of the children of the Junior House cannot be so confidently estimated as that of the older children whose life is regulated by time table.

A tentative assessment is as follows :—

Table XVI.

— —Total heat production. 24 hours.

Boy 10 years ....Calories.

2,6959 9 . . . 8 „ ........................... _ . . . . . . . . 2,191

Girl 11 „ ........................... . . . . . . . . 2,42999 ............... . . . . 9 „ ........................... . . . . . . . . . . . . 2,223




Section III.—D ietary Studies at the School and J unior School.

When the investigation was undertaken, Professor Starling advised that an accurate study should be made of the food consumption of individual boys and girls, especially of those who were acting as subjects for the metabolism experiments. As far as possible this has been carried out.

No attempt was made to modify the diet in any way, nor were the subjects under observation isolated from their fellows. Over a period of many weeks, two or more children would be weighing their food each day, and the routine was soon accepted so much as a matter of course, that we believe that the 100 boys and girls who submitted to a close scrutiny of their food consumption were, with very few exceptions, perfectly natural and normal about it. On the whole, our results perhaps err in slightly understating the real food intake.

Method.—The method adopted was to provide good spring-balances, accurate to | oz., and “ diet sheets,” printed so as to give the minimum of trouble in filling in the description of the food and the quantity eaten. These being on the table, the subject filled in his diet sheet as the meal proceeded, and it was found easy to be quite accurate in weighing vegetables, gravy, etc., separately, and also in deducting the weight of the plate and of anything not actually eaten. In the case of all the younger or less reliable subjects, the weighings were performed by Mrs. Hodson or the writer, and it is believed that a very fair level of accuracy is maintained throughout these studies. The observations were carried out in three consecutive terms, so that all seasons and weathers are represented. We do not, however, find any very consistent seasonal variation either in individuals or averages ; this may be because the numbers studied were too small.

Not more than six days’ consecutive diet observations were made on any boy or girl, because, as the routine became irksome, appetite was affected. The majority of the studies are of one day only. This is admittedly not a very good arrangement, but by no other means could a large number of individuals be studied, and it was thought that averages arrived at by this means were likely to be more generally valid than if obtained from fewer individuals over longer periods.

The diet sheets when completed were carefully calculated from analyses of the cooked foods. The analyses were for the most part drawn from well- known sources (Ref. 7, 8, 9, 10), but we were fortunately able also to secure new analyses of a number of cooked foods for which no data were formerly available. These values are given in Appendix II.




The Food.— Some general remarks should perhaps be made on the schoolcommissariat. The investigation did not begin till the food crisis had so far passed that it was possible to procure normal supplies (July, 1919). The food supplied is good in quality and sufficient in quantity, as examination of the ensuing tables will show. I t is plain, palatable, and well-served. There is abundance of milk, fruit and fresh vegetables, so that it may be assumed that the supply of “ accessory factors ” and mineral constituents in the diet is not inadequate.

The school meals are arranged as follows :—

7.45 a.m., breakfast; 1 p.m., dinner ; 6 p.m., tea.

At 11 and 3, buns, biscuits or fruits are provided, with milk in addition for those requiring i t ; before bed, again, most children take milk and biscuits.

Consumption of Food at the Three Meals.—It may be of practical use to note how the total consumption of the day is distributed over the meals and “ extras.” Thus :—

BreakfastDinner ..TeaExtras ..

Total .. .. 3,172 „

1,023 calories" 924 „822 „403 „

Average of 20 >Boys and Girls

12-18 years.

A breakfast of round about 1,000 calories is general in these studies ; attention is drawn to this, as it seems that the importance of a good breakfast has not always been appreciated at schools. I t is usual to find that 30 to 40 grams of fat, in one form or another, are taken by adolescents at breakfast.

In the matter of “ extras,” it must be noticed that no sweets or cakes from home or from tuck-shops are allowed. The “ extras ” are simply the biscuits, buns and fruit which are provided for all at 11, 3.30 and 8.30.

Table XVII shows the proportions of the proximate principles in the school food. The proportion of protein is calculated as a percentage of the total

. total caloriesweight, and also as the so-called “ Nutritive Ratio, %.e. ~ t]orjes profrein ’




Table XVII.—Quantity of Proteins, Fats and Carbohydrates in Diet.

1. Average from 20 diet sheets, 10 boys and 10 girls of 17 and 18 years.

ProteinFatCarbohydrate

123-0 grams = 504-3 calories147-0 „ = 1,367-1 „486-0 „ = 1,992-6 „

756-0 „ 3,864-0 „

Protein = 16-3 per cent. Nutritive ratio 7-8 to 1.

2. Junior House.—Average from 25 diet sheets, boys and girls, 8-12 years.

Protein ...............Fat ..........................Carbohydrate .............. :

: :

: :

: 85-592-9

384-6

grams = 350-5 calories„ = 864-4 „„ = 1,576-9 „

563-0 2,791-8 „


3. Montessori School.-—Average from 8 diet sheets, boy and girls of 5 and 6 years.

Protein ..........................Fat .........................Carbohydrate ..............

................................. -.............. 60 • 7 grams = 248 • 9 calories69-7 „ = 648-2 „

240-8 „ = 987-1 „

371*2 » 1,884-2 „


4. Average from 7 vegetarians’ diet sheets, boy and girls, 14-17 years.

ProteinFat ..........................Carbohydrate :

. :

: :

:

: :

: 105 • 9 grams = 434 • 2 calories109-7 „ = 1,020-2 „472-1 „ = 1,935-7 „

687-7 3,390-1 „


Average Results.—Only the average of 157 diet studies is given here. In the actual data there is considerable variation from one child to another of the same group, or for the same child from day to d ay ; a deviation of 200 calories is fairly general. Factors influencing this are weather, special exertion such as a match, personal peculiarities of appetite, and the inevitable “ like and dislike ” factor.




It is shown in Table XVII that the averages of food intake for different ages are drawn from unequal numbers of studies ; for the younger children especially, data are sparse, so that the personal factor is dominant.

One fact stands out clearly—that, between the ages of 10 and 16 years, there is practically no difference in the food requirements of boys and girls. The steep rise in the intake of boys over 16 is noticeable. I t is probable that the fewness of the studies on children of 7 to 10 years, and the conditions of their life at the Junior House, are also responsible for the apparent excess of the boys’ needs over the girls’ for these years.

Table XVIII.—Average Food Consumption at Different Ages. Boys and Girls.

Calories.

No. of studies.Total. Per kg.

Boys—18 years 4,964 81 417 „ ....................................... 3,933 63 616 „ ....................................... 3,519 74 315 „ ....................................... 3,339 54 1114 „ ....................................... 3,171 71 913 „ ....................................... 2,614 67 1012 „ ....................................... 3,159 84 411 „ ....................................... 2,544 81 310 „ ...................................... 2,856 86 29 „ ...................................... 3,568 112 18 „ ...................................... 2,797 93 27 „ ....................................... 2,570 106 26 „ ....................................... 1,712 80 1

Girls—17 years 3,310 56 1716 „ ....................................... 3,020 54 615 „ ....................................... 3,092 58 814 „ 3,170 68 713 „ ....................................... 3,171 74 712 „ ....................................... 2,757 67 1611 „ ....................................... 2,848 81 1310 „ ....................................... 2,756 97 19 „ ....................................... 2,537 96 78 ,, — — —7 „ ....................................... _ — —

5 and 6 years 1,751 79 7

Comparison with Estimates of Children's Food Requirements.—A table of food allowances for children is given in “ Food Requirements of Man ” (6). Our observations show an average excess of 22 per cent, over the figures there given. Still greater is our excess over the scale suggested by Gillett, quoted by Sherman (7). This result is only to be expected, since the standard of living




at Bedales, though not luxurious, is of course above that of the bulk of the nation here, or in America.

When our figures for boys’ food-consumption are compared with those

A ge sy r s . 6 7 8 9 10 II 12 13 14 15 16 17 18 19

- -X---

A ge 5 y rs . 6 7 8 9 10 II 12 13 14 15 16 17 18 19

'X--- >

x GirlD B o y - Junior House A Girl - Junior House

Average Food Consumption observed in Boys and Girls.




obtained by Gephart in an American boarding-school, it would appear that English boys eat about 25 per cent, less than young Americans. However, besides the fact that the American nation as a whole seems to eat more than the British, two points should be remarked which tend to lessen this great difference. In the first place, the children we have studied are not allowed any extras in the shape of sweets and “ tuck-shop ” dainties, while Gephart calculates that his boys added 600 calories to their daily rations in the shape of chocolate. Secondly, our studies were individual, while it is possible that in the other case a proportion of the calculated food intake was not actually consumed.

Table XIX.—Summary of Observations on Food Consumption.

Age.

Calories.

Total. Per kg. Per sq. metre.

Boys—16-18 years (inclusive) . . . . . . . . 4,155 71 2,50413-15 „ . . . . . . . . 3,044 67 2,10610-12 „ . . . . . . . . 2,887 84 2,4486-9 „ . . . . . . . . 2,643 105 2,907

Girls—16-17 years (inclusive) . . . . . . . . 3,234 55 1,94613-15 „ . . . . . . . . 3,131 66 2,14010-12 „ . . . . . . . . 2,806 74 2,2345-9 „ . . . . . . . . 2,144 87 2,264

Summary of Section III .

Table XIX summarises the findings of individual studies of the food consumption of 102 children under good conditions. (See also chart on preceding page.)

A flat rate of 3,000 calories per diem for both boys and girls from the age of 10, would be a satisfactory allowance. Children between 6 and 10, according to size and activity, probably need 2,500 to 3,000 calories.

Boys over 16, at least if still at school, average a food intake of 4,000 calories.

S ection IV.— B alance of E n e r g y E x pe n d it u r e a n d F ood

Co n su m ptio n .

If the necessarily large errors involved in an unacademic “ real life ” research are fully borne in mind, a comparison may usefully be made between the findings of the two sides of this investigation, viz., the metabolism measure-



ments by indirect calorimetry, and the dietary observations, which were carried out and worked up independently of each other.

A table showing the balance of calorie intake and output is therefore here given and discussed.


Table XX.—Balances of Food Intake and Energy Output.—Boys and Girls.

*— Calories. Available

calories.Net intake

in excess of .output.

Boys—years Food intake....

Energy expenditure4,309 4,128

3,901

227

Per cent.

5*8

15x2 Food intake .... Energy expenditure

3,263 3,1263,096 1 0

30

13x2 » Food intake...............Energy expenditure

3,010 2,8842,681

203 7-5

13x2 >>(under-developed)

Food intake .... Energy expenditure

2,534 2,4282,318

110 4-7

Girls—17-& years Food intake...............


3,214

16 0-5

15 T\ „ Food intake .... Energy expenditure

2,980 2,8552,828

27 1-0

14A „ Food intake .... Energy expenditure

3,013 2,8862,828

58 2-1

12A „ Food intake...............Energy expenditure

3,017 2,8902,667

223 8-3

12A »(under-developed)

Food intake...............Energy expenditure

2,249 2,1542,099

150 7 1

B.R. 12 years Food intake .... Energy expenditure

2,927 2,8042,733

71 2-02 GVOL. xciv.— B.



400 Miss E. M. Bedale. Energy E xpenditure and

Table XX.—continued.

— — Calories. Availablecalories.

Upt intake in excess of

output.

Girls—11^ years Food intake...............


2,483

Per cent.

19 0-8

Junior House—Boy, 10|£ years .... Food intake...............


2,695

131 4-9

99 9 r a 99 Food intake .... Energy expenditure

2,645 2,5342,191

343 15-6

Girl, years .... Food intake...............Energy expenditure

2,721 2,6082,429

179 7-4

99 9T63 ,, Food intake...............Energy expenditure

2,576 2,4682,223

245 11-0

The agreement between the two sets of observations is sufficiently close to warrant an examination of its plausibility and significance.

The probable errors in the estimates both of intake and output have been discussed in submitting the data. To these must be added the fact that the figures for Food Consumption are the means of numbers of observations on different days, at different seasons, and on similar but not always all the identical subjects from whom the metabolic data are drawn. The figures for Energy Output, on the other hand, are those estimated for actual single days, regarded as typical, but probably not giving the same value as would be obtained from averaging various days at various seasons. ,

I t is customary to allow an excess of 10 per cent, in the gross food allowance in calories, over the estimated energy requirements. As, however, our studies of food consumption were individual and fairly accurate, and the food values were calculated from analyses of cooked foods, it seemed desirable to discount as much of this 10 per cent, margin as is allowed for losses in cooking and food left on the plate, and to consider only the physiological waste.



The availability of the foodstuffs under good conditions is given as follows (12):—

Protein’ '92 *6 per cent. Fat, 94 per cent. Carbohydrate, 97 *7 per cent.

We have therefore a loss of only about 4 per cent, to consider—the exact percentage varying with the proportions of the three food principles in the dietary. The “ available calories ” given in Table XX are calculated on the basis of a loss of 4 -2 per cent, undigested in the faeces.

Growth.

The question of food requirement for growth is of great interest and importance. The general drift of these observations seems to be that, if the activity of the child could be completely measured, the correspondence between intake and output would be extremely close, and yet normal growth takes place.

Table XXI shows the average growth per annum of the groups of children studied during the years 1919-21.

Food Requirements o f Childre?i at School. 401

Table XX.—Average Growth per annum of “ Typical Children.”

Group

Average increase per annum, 1919-21.

Equivalent of weight

increment in

Height. Weight.calories

per diem.

Boy, 17-f* years ...............cm.3-2

kg-4-0 8-3

„ „ ........................... 4-4 4-7 10-099 13jo 9? 6-4 5-3 n o9 9 13tV >> 5-1 3-4 7-0

(under-developed)Girl, 17t63 years ........................... 0-5 1 1 2-2

„ 15t92 » ........................... 1-5 2-0 4-299 99 - 3-8 5 1 10-5„ 1 2 * „ ........................... 5-4 7-3 15-2,, 1 2 * ,, 5-2 4-0 8-3

(under-developed)Girl, B.R., 12 years........................... 4-7 6-5 13-4

„ 1 1 * years ............... 7-1 5-5 12-1Junior House— ,

Boy, 1 0 * years ........................... 5-1 2-6 5-4\ 9 ST?2 ,, 3-6 2-3 4-8

Girl, 11* years 5-0 3-5 7-399 9T6a ,, 4 1

!2-5 5-2

A calorie equivalent to the weight increment (per diem) is tentatively calculated from Plimmer’s figure for the calf, the whole animal, alive, viz., 1 kilogram = 758 calories (13). The daily retention of calories in the body is




clearly very small indeed, although “ the amount of energy required in the food in order to produce this addition of weight is probably considerably higher ” (6). I t would appear from these few studies that, for children of school age, the food requirement for growth is perhaps not more than 2 per cent, or 3 per cent, of the total food intake.

Conclusion and Acknowledgments.—In conclusion, it may be said that children who enjoy a rational freedom in their school life, fully live up to a generous nutritive income, to the undoubted benefit of their development in every sense.

From the age of 8, the daily food requirement of boys and girls is not less than 2,500 available calories. From 12 to adult life for girls, and from 12 to about 16 for boys, a flat rate of 3,000 calories would be a satisfactory scale for schools to adopt. Boys from about 16 years, if big and athletic, require about 4,000 calories per diem.

Very grateful thanks are due to Mr. J. H. Badley, head-master of Bedales, for his generosity in giving permission and all facilities for carrying out this work at the school. Warm thanks must also go to the staff and the boys and girls, both of the School and of the Junior House, for their constant support and co-operation.

The research was carried out under the direction of Professor Starling, to whom I am indebted for much help. I wish also to acknowledge gratefully the kindness of Professor Cathcart in providing a training in the technique of the Douglas-Haldane method ; and of Mrs. Hodson, who initiated the research at the school and helped in its prosecution throughout.

Thanks are due to Mr. J. B. Barlow, of the Ministry of Food, for the repeated loan of a calculating machine, and to Dr. Cannan, of University College, for having special analyses made of cooked foods sent from the school.

A p p e n d ix I.—E x pe r im en t s on Ch il d r e n a t t en d in g the V illage S chool.

{Summary.)About 120 experiments were carried out'on the children of the village

school, at times when the usual subjects dispersed for holidays. These children were enthusiastic volunteers, but were not quick to grow accustomed and indifferent to the apparatus, so that many experiments were vitiated by psychical interference with the respiratory rhythm.

I t was not possible to get post-absorptive resting experiments. The energy expenditure of the boys out of school was considerably higher than that of



Food Requirem ents o f Children at School. 403

girls of the same age, but this was clearly due to training in decorum on the part of the girls. In experiments on walking (some of the children walk two miles to school) the expenditure is approximately equal per square metre for boys and girls.

A feature of some interest is that the respiratory quotient in the great majority of these observations was higher than in corresponding cases among the children of Bedales. While this may have been due in part to mental excitement, it is at least possible that it was accounted for by an excess of carbohydrate in the diet. Enquiry showed that there was in many instances a deficiency of fat and protein, and a few of the children examined were fairly marked cases of malnutrition. There was no real poverty in the district, and there was no evidence that the food of any of these children was seriously inadequate in quantity. In the winter the children were warmly and comfortably clothed, but during a spell of very hot weather, when experiments were in progress, it was found that the activity of the boys was both impeded and made much more costly by the quantity and weight of the clothing which they wore.

Appendix II.—Analyses of Cooked Foods, sent from the School.

Samples. Water. Fat. Protein. Carbohydrate. Ash. Calories.

Per cent. Per cent. Per cent. Per cent. Per cent. Per 100 gins,Baked jam roll 31-6 161 4-6 47-2 0-5 361-8Suet pudding and jam 37-4 14-2 5-4 42-2 0-8 327-2Suet and date pudding 60-6 6-6 2-9 30-6 0-4 198-7Fig pudding............... 41-4 4-0 3-9 50-0 0-7 258-2Lemon pudding 44-5 7*4 7-0 40-7 0-4 264-7Ginger pudding 35-7 7-0 7-6 48-3 1-3 294-4Treacle pudding 30-5 7-4 8-7 52-5 0-8 320-0Sausage pie ............... 31-6 17-0 6-7 44-6 1-1 367-9Cheese tart ............... 26-6 7-9 11-3 53-1 1 0 337-9Baked ground rice .... 73-6 1-9 1-9 22-2 0-5 116-2Baked rice ............... 69-3 1-8 3-3 25-6 0-5 130-8Baked macaroni 74-7 1*4 3-8 19-6 0-5 108-7Baked sago ............... 76-1 1*6 1-9 20-2 0-3 105-5Bird’s custard 80-1 4-5 8-8 6-4 0-2 104-1Cornflour shape 84-7 1-0 1-8 121 0-4 65-2Macaroni cheese 69-8 9-6 6 1 131 1-4 168-2Cauliflower cheese .... 85-5 1-9 2-6 8-9 1 1 64-9Potato, parboiled and

fried ............... 66-2 7-5 8-9 16-0 1-4 172-0Vegetable pie 25-3 14-6 6-8 52-4 0-9 378-1Kippered herring

(fried) ............... 64-1 9-6 22-4 1-4 1-8 189-7Cod and sauce 70-5 12-1 150 1-4 1 0 179-8Fish pie ............... 69-8 5 0 3-7 19-8 1-7 142-9S te w ........................... 79-1 4-6 11-0 4-4 0-9 105-9Irish stew ............... 68*8 8-8 9-3 12-3 0-8 170-4Boiled mutton 59-1 17-4 16-3 6-1 0-6 255-3Scotch broth (thick) 86-2 2-9 2-6 7-9 0-5 69-7Lentil soup (thick) .... 77-7 1-3 6-2 13-6 1-2 93-3

2 HVOL. XCIV.— B.



404 Mr. G. V. Anrep.

REFERENCES.

(1) Cathcart, “ Method of Estimating Energy Expenditure,” ‘ R.A.M.C. Journal,’ 1918.(2) G r e e n w o o d ,Hodson & Tebb, 44 Metabolism of Female Munition Workers,” ‘ Proc.

Roy. Soc.,’ 1919.(3) Krogh, 4 Respiratory Exchanges of Animals and Man.’(4) C a t h c a r t , * Energy Expenditure of the Infantry Recruit,’ 1919.(5) Du Bois, 4 Clinical Calorimetry X II,’ Russell Sage Institute, 1916.(6) ‘ Food Requirements of Man,’ Royal Society Food (War) Committee.(7) Sherman, 4 Chemistry of Food and Nutrition,’ 1918 Ed., p. 371(8) Lush, 4 Science of Nutrition,’ 1919 Ed., p. 559.(9) Hutchinson, 4 Food and Principles of Dietetics.’

(10) McKillop, 4 Food Values,’ Routledge, 1917.(11) Roper, ‘ Physical Education,’ Allen & Unwin, 1917.(12) Starling, 4 Physiology,’ Ed. 1920, p. 698.(13) Plimmer, 4 Analyses and Energy Value of Food,’ 1921.

The Irradiation o f Conditioned Reflexes.By G. Y . A nrep .

( Communicated by Prof. E. H. Starling, F.R.S. Received October 24, 1922.)

(From the In s titu te of Physiology, U niversity College, London.)*

I. T he I rradiation of Tactile Conditioned R eflexes.

The present communication is a result of an investigation upon the irradiation of cutaneous conditioned reflexes established by different methods.

Under the name of conditioned reflexes are recognised all reflexes peculiar to individual animals and acquired by them in the course of their existence. The organism at birth presents merely greater or lesser possibilities for the formation of these reflexes, and their formation depends only on the conditions under which the animals live. The word “ conditioned ” is merely used in order to denote an important property which these reflexes exhibit, namely, their very great dependence on innumerable conditions. I t distinguishes them also from all other reflexes which act through the lower centres, work with a remarkable regularity, and are, in fact, “ unconditioned," and exist in the animal from birth to death.

The method of conditioned reflexes is a method of experimental formation

* All the experiments described in this communication were performed in 1917-18 in Prof. Pavlov’s Laboratory at the Institute of Experimental Medicine, Petrograd.



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