Share Values and Daily Requirements of Different Food Nutrients^ 



^These values are based on the Recommended Daily Allowances for Specific Nutrients sug- 

 gested by the Committee on Foods and Nutrition of the National Research Council in May, 1941. 



-The fact that there have been too few analyses of the niacin content of food makes it 

 impracticable to calculate "shares" of niacin. 



natural foods, he will also get sufficient supplies of phosphorus, niacin and 

 all the other essential nutrients. 



Requirements in Shares No single food furnishes a balanced diet. 

 That is, nothing we eat has exactly the proportions of fuel, protein, calcium, 

 and so on that are listed for one "share". If we analyze various foods and 

 calculate what they actually contain in proportion to 100 Calories of energy, 

 we find that most of the other essentials are present either in much larger 

 or much smaller ratios than 1.0. We can see this at a glance in the table on 

 the opposite page. All the food we eat yields energy — except water, minerals 

 and vitamins. Conversely, various essentials are obtained with most of the 

 energy foods, unless one is restricted to pure sugars and fats. But to get an 

 adequate diet it is necessary to take a variety of foods. 



By comparing various foods, we discover that some yield one essential 

 in relatively large proportions, whereas others are rather restricted in their 

 offerings. It is easy to make a great ado about a particular dish or prepara- 

 tion being exceptionally rich in a particular vitamin or in "quick energy", 

 and to overlook everything else it lacks (see illustration, p. 129). 



For most people a variety of foods selected in share units according to 

 the total energy requirements will supply all needs. Growing children need 

 a greater number of "shares" of protein, calcium, iron, vitamin A, and 

 ascorbic acid in proportion to their "shares" of energy than do adults. Also 

 special circumstances (such as the need for a reducing diet) or special con- 

 ditions (such as pregnancy and lactation) require that the relative number 



130 



