12 DEPARTMENT BULLETIN 975, U. S. DEPT. OF AGRICULTURE. 
Chart 2. One Pound of Sweet Potatoes. 
(2 large.) 
A pound of sweet potatoes supplies about 445 calories of energy, 6 grams 
(about i ounce) of protein, 0.07 gram of calcium, 0.15 gram of phosphorus, 
and 0.8 milligram of iron. It would furnish, therefore, 13 per cent of the 
energy a man needs daily, 6 per cent of the protein, 10 per cent of the calcium, 
12 per cent of the phosphorus, and 12 per cent of the iron. This is shown in 
the following chart: 
ENERGY 
ntim 
FR0TESN 
cm 
CALCIUM 
torn 
PHOSPHORUS 
mm 
IRON 
to 2o 3.0 to .sp ap 70 Bp Sjp 
Chart 2. — Proportions of energy, protein, calcium, phosphorus, and iron needed per man 
per day furnished by 1 pound of sweet potatoes. 
Chart 3. One Pound of Onions. 
(4 or 5 medium-sized.) 
One pound of onions supplies about 210 calories of energy, 6 grams (about 
i ounce) of protein, 0.14 gram of calcium, 0.18 gram of phosphorus, and 2.2 
milligrams of iron. It would furnish, therefore, 6 per cent of the energy a 
man needs daily, 6 per cent of the protein, 21 per cent of the calcium. 14 per 
cent of the phosphorus, and 15 per cent of the iron. This is shown in the 
following chart : 
ENERGY 
6* 
PROTEIN 
GfM 
CALCIUM 
2/hm 
PHOSPHORUS 
A» 
IRON 
| To 2p 3p 4f Jo if 70 Sp 96 
Chabt 3. — Proportions of energy, protein, calcium, phosphorus, and iron needed per man 
per day furnished by 1 pound of onions. 
