Her daily food requirements would probably be approximately 2,235 calories. This estimate would be increased, if she were obliged to do much heavy lifting, scrubbing of beds, or other duties requiring the expenditure of much effort. It would be decreased if the hours spent in study and class room work were increased and the hours on the ward shortened. The estimation may be made as follows,

Sleeping 8 hrs.110 × 0.42 × 8=370.0 calories
Sitting at meals 2 hrs.110 × 0.65 × 2=143.0 calories
Sitting in class 1 hr.110 × 0.65 × 1=71.5 calories
Studying, 2 hrs.110 × 0.65 × 2=143.0 calories
On duty 9 hrs.110 × 1.10 × 9=1089.0 calories
Off duty (walking briskly) 2 hrs.110 × 1.90 × 2=418.0 calories
Total for day 2234.5 calories

This estimate may be made to suit any individual, the man in the office or the one working on the streets, the woman living at home or the one spending eight or ten hours scrubbing the floors of a great office building; it is simply a matter of adjusting the calories in the dietary to meet the requirements of body weight and muscular activity.

Energy Requirements for Children.—In estimating the energy needs of children, the above method is not satisfactory, since the storage of material for growth must be considered, as well as the activities of the body. The growth period includes the years from birth to the eighteenth year, after which time the food requirements of the body are made on a basis of weight and muscular activity, as in all adults. The table on the following page shows the food allowances made for healthy children; in the feeding of malnourished or underweight children, more food in proportion to age is given in order to overcome the handicap under which they are suffering.

Food Allowances for Healthy Children[23]

AgeCalories per Day
YearsBoysGirls
Under 2 900-1200 900-1200
2-31000-1300 980-1280
3-41100-14001060-1360
4-51200-15001140-1440
5-61300-16001220-1520
6-71400-17001300-1600
7-81500-18001380-1680
8-91600-19001460-1760
9-101700-20001550-1850
10-111900-22001650-1950
11-122100-24001750-2050
12-132300-27001850-2150
13-142500-29001950-2250
14-152600-31002050-2350
15-162700-33002150-2450
16-172700-34002250-2500

Calories per Pound of Body Weight per Day.[24]

YearsCalories per pound, per day
Under 1 year45
1-240-43
3-437-40
4-537-40
5-635-37
6-734-35
7-832-34
8-930-35
9-1030-35
10-1128-32
11-1228-32
12-1328-32
13-1425-30
14-1520-25
15-1620-25
16-1720-25

After which time the food requirements are based on degree of muscular activity, boys and girls of seventeen years and over requiring as much food as men and women.

Children, like adults, differ in degrees of activity; that is, one child may be very active, running and playing more strenuously than another. Hence a margin of safety must