BULLETIN 903, U. S. DEPARTMENT OF AGRICULTURE. 
STANLARO FOR COVITPHIYISOV 
4QOO CALORIES 
CARROT 479d OSL SEL TS 
ZOS CALOAVES S35 CALOLVES 210 CALORIES 
FOOT CELERY = TURMP ONION 
285 CALORIES 1/80 CALORIES 220 CALORIES 
BALAD VT/L IO 
4185 CALOPIES BS CALOAIES 
Fig. 2.—Energy value of edible portion of root vegetables per pound. Just as an 
engine must have fuel as a source of the power it supplies, so the body, which is 
a living engine, uses its food as fuel to supply the energy for the work it per- 
forms. For measuring the energy value of food the calorie is the most con- 
venient unit. It represents in round numbers the amount of heat required to 
raise 1 pound of water from 0° to 4° F., and equals very nearly 3,087 foot- 
pounds. If it be assumed that the large square at the head represents 1,000 
calories, the amount of energy which a pound of the different succulent vege- 
tables would supply is shown in graphic form by the black rectangles used for 
comparison. These values are, in general, low as compared with such a food as 
bread. Nevertheless, the succulent root vegetables as a group contribute ma- 
terially to the energy value of the diet in addition to furnishing material for 
the structural needs of the body. They are especially important for the mineral 
elements they supply, and in this respect rank high in comparison with other 
kinds of food, 
