COMPLETE AND INSUFFICIENT DIETS 



93 



The energy in food is measured in terms of heat units called 

 calories. A calorie represents the amount of heat required to 

 raise the temperature of one gram of water one degree centigrade. 

 When we deal with food values, we use the large calorie, which 

 is 1000 times the small calorie. In other words, the large calorie 

 is the amount of heat required to raise one kilogram (1000 grams) 

 one degree centigrade. When we speak of the caloric value of a 

 food we mean the power of food to yield heat units. Food chem- 

 ists group our food nutrients into the five classes which were 

 studied in general science or elementary biology. The table on 

 page 94 will help you recall certain facts concerning these classes 

 of nutrients. 



Complete and insufficient diets. Even if a person ate some 

 of all the nutrients, it would not necessarily mean that he was 

 getting a sufficient or a complete diet. If the diet is composed 

 entirely of the nutrients from the same food, it is usually insuf- 

 ficient, and the person using this diet may suffer from malnutri- 

 tion. Careful investigations have disclosed that 15 to 25 per cent of 

 the children in the United States are suffering from malnutrition. 



Gliaden and milk diet Gliaden diet 



Rats need a variety of food materials. These four-month-old rats are from the same litter 

 and have been fed the same quantity of food, but of different variety. Note the differences 

 in size. 



Protein insufficiency. An investigation was made, by McCollum 

 and others, in a certain institution for children to discover the 



