It is evident that the energy requirement is proportional to the amount of mechanical energy expended.
One may turn now to the fuel needs in terms of calories in certain industrial pursuits. According to Becker and Hämäläinen, the quantity of extra metabolism per hour required in various pursuits is as follows:
| Extra calories of metabolism per hour due to occupation | |
|---|---|
| Occupations of women: | |
| Seamstress | 6 |
| Typist[5] | 24 |
| Seamstress using sewing machine | 24-57 |
| Bookbinder | 38-63 |
| Housemaid | 81-157 |
| Washerwoman | 124-214 |
| Occupations of men: | |
| Tailor | 44 |
| Bookbinder | 81 |
| Shoemaker | 90 |
| Carpenter | 116-164 |
| Metal worker | 141 |
| Painter (of furniture) | 145 |
| Stonemason | 300 |
| Man sawing wood | 378 |
To use this table one may seek the basal metabolism of the individual, add 10 per cent. for sixteen hours of wakefulness when the person is sitting or standing, and then multiply the factors in the last table by the numbers of hours of work. For example, if one takes the individual weighing 156 pounds, one obtains the following requirements of energy if his business were that of a tailor and he worked eight hours a day:
| Calories | |
|---|---|
| Sleeping 8 hours at 70 calories per hour | 560 |
| Awake 16 hours at 77 calories per hour | 1232 |
| Add for work as tailor 8 hours at 44 calories | 352 |
| 2144 |
After this fashion one might calculate his food requirements had he followed occupations other than that of tailor:
| Occupation | Calories of metabolism per day |
|---|---|
| Bookbinder | 2440 |
| Shoemaker | 2510 |
| Carpenter | 3100 |
| Metal worker | 2900 |
| Painter | 2950 |
| Stonemason | 4200 |
| Man sawing wood | 4800 |
These figures make no allowance for walking to or from the place of employment.
The data here given are inadequate to cover the industrial situation, but they show clearly that heavy work cannot be accomplished without a sufficient amount of food-fuel.
The food-fuel with which to accomplish work is necessary not only for the soldier, but for the workman behind the line, and it should be adequate in quantity, satisfactory in quality, and not exorbitant in cost.