HOW FOODS MEET BODY NEEDS. 3 



phos^Dhorus, and iron are slightly higher than what is considered a 

 minimum requirement to cover possible waste and lack of utilization. 



The needs of a man at moderately active muscular work are almost 

 universally adopted as the unit for measuring food needs, and for 

 this reason they are used in this publication. For some persons, it 

 may be more to the jDoint to know what percentage a given food sup- 

 plies of the nutrients needed by the average adult, by the average 

 family, or by some other individual or group. To change the per- 

 centages so that they will apply to the needs of the average adult, the 

 man doing little or no muscular work, or the woman doing moder- 

 ately active muscular work, they need only to be increased one-fourth. 

 This must not be taken to mean that the man doing little or no work 

 needs one-fourth more food than the man doing active work, but that 

 he derives a higher proportion of the food needs of his body from a 

 pound of a given food. For the woman doing little or no muscular 

 work, they should be increased one-half. For the average family, 

 which is supposed to consist of a man and a woman, both doing 

 moderately active muscular work, and three young children, they 

 should be only three-tenths as great. For example, a pound of oat- 

 meal, which supplies 52 per cent of the fuel needed daily by a man 

 at moderately active work, will supply 65 (1|-X52) per cent of the 

 fuel needed by the average adult, 78 (1^X52) per cent of the fuel 

 needed by a woman who does little or no muscular work, and about 

 16 (x^iyX52) per cent of the fuel needed by the average family. ]More 

 detailed information on working out the energy requirements of 

 various individuals and families is given in other publications of 

 this department.^ 



The charts will be found useful in various ways. The heavy lines, 

 even without the figures that accompany them, show for what con- 

 stituents the various foods are specially valuable. For example, the 

 comparatively long lines representing iron in spinach, calcium in 

 cheese, fuel in butter, phosphorus in peanuts, and protein in such 

 foods as milk, eggs, and meat, show at a glance the nutrients in which 

 these foods are rich. 



The lines and figures also furnish an easy means of comparing one 

 food with another. The energy lines on the sweet and Irish jootato 

 charts, for instance, show that the former has a higher fuel value. 

 The protein lines on the oatmeal and rice charts show that as a source 

 of protein, oatmeal excels rice. The calcium lines on the string boan 

 and tomato charts show that the former is richer than the latter in 

 lime. The pliosphorus linos in corn and spinach show that corn is 

 richer in this particular element. The iron line in lettuce as com- 



1 IT. S. Dept. Agv.. Farmers' Bui. 142, I'rinciples of Nutrition svnd Nutritive Value of 

 Food ; Farmers' Bui. 1228, A Week's Food for an Average Family. 



