284 FOODS AND DIETARIES 



A Mixed Diet Best. Knowing the proportion of the different 

 food substances required by man, it will be an easy matter to 

 determine from the tables and charts shown you the best foods 

 for use in a mixed diet. Meats 'contain too much nitrogen in 

 proportion to the other substances. In milk, the proportion of 

 proteins, carbohydrates, and fats is nearly right to make proto- 

 plasm ; a considerable amount of mineral matte* being also pres- 

 ent. For these reasons, milk is extensively used as a food for 

 children, as it combines food material for the forming of proto- 

 plasm with mineral matter for the building of bone. Some vege- 

 tables (for example, peas and beans) contain a large amount 

 of nitrogenous material but in a less digestible form than is found 

 in some other foods. Vegetarians, then, are correct in theory 

 when they state that a diet of vegetables may contain every- 

 thing necessary to sustain life. But a mixed diet containing 

 meat is healthier. A purely vegetable diet contains much waste 

 material, such as the cellulose forming the walls of plant cells, 

 which is indigestible. It has been recently discovered that the 

 outer coats of some grains, as rice, contain certain substances 

 (enzymes) which aid in digestion. In the case of polished rice, 

 when this outer coat is removed the grain has much less food value. 



Daily Fuel Needs of the Body. It has been pointed out that 

 the daily diet should differ widely according to age, occupation, 

 time of year, etc. The following table shows the daily fuel needs 

 for several ages and occupations : 



DAILY CALORIE NEEDS (APPROXIMATELY) 



1. For child under 2 years . . . . 900 Calories 



2. For child from 2-5 years 1200 Calories 



3. For child from 6-9 years 1500 Calories 



4. For child from 10-12 years 1800 Calories 



5. For child from 12-14 (woman, light work, also) . . 2100 Calories 



6. For boy (12-14), girl (15-16), man, sedentary . . . 2400 Calories 



7. For boy (15-16) (man, light muscular work) . . . 2700 Calories 



8. For man, moderately active muscular work .... 3000 Calories 



9. For farmer (busy season) 3200 to 4000 Calories 



10. For ditchers, excavators, etc 4000 to 5000 Calories 



11. For lumbermen, etc 5000 and more Calories 



