032 XIV. NUTRITIONAL VALUE OF FATS 



involved. For example, the requirement for these components ^'aries with 

 sex, being higher in males than in females. 



Essential fatty acids also serAC as protective agents against x-irradiation 

 injury. ^21, 422 Most recently it has ])een shown that the LD50 from a single 

 exposure of x-irradiation reached the maximum level when 80 mg. of lino- 

 leate was administered to rats.*"^' The survival rate was considerably 

 higher when the animals had received 15% cottonseed oil than when a fat- 

 free diet had been given. ^-^•''-* 



It is not known Avhether or not the beneficial effects of fat are to be 

 traced exclusively to their EFA content. There is some indication that the 

 capacity for work, and the sparing action of fats on the "wear and tear 

 quota" of protein metabolism, may not be directly related to the EFA con- 

 tent of the diet. 



(2) Conclusions Based upon Experiments on Man 



There is some question as to how far one can apply the results obtained 

 with rats in interpreting the requirements for human nutrition. According 

 to Brandt*-^ the daily intake of fat by the British increased from 99 g. per 

 day before World War I to a figure of 124 g. by 1934. A similar fat con- 

 sumption was noted for Americans and Germans during the latter period; 

 fats accounted for 30% of calories in their dietaries at that time. In sharp 

 contrast to this relatively high intake by the Occidentals, the intake by 

 Orientals was show^n to be quite low. Shen^-^ estimated that the soldiers 

 of South China during World War II ate fat in the amount of only 3% of 

 their total caloric intake w^hile How^e^" calculated the average consumption 

 of the American soldiers in World War II as 40%. 



The Food and Nutrition Board of the National Research Council 

 (United States) ^^* made the following suggestions as to the human require- 

 ment for fat : 



«i A. L. S. Cheng, T. Graham, R. B. Alfin-Slater, and H. J. Deuel, Jr., ./. Nutrition 

 55,647-653(1955). 



«2 A. L. S. Cheng, M. Rvan, R. B. Alfin-Slater, and H. J. Deuel, Jr., J. Nutrition, 52, 

 637-644(1954). 



^"^^ A. L. S. Cheng, Personal communication, 1955. 



*" A. L. S. Cheng, T. Graham, R. B. Alfin-Slater, and H. J. Deuel, Jr., Federation 

 Proc.,i4, 429-430 (1955). 



425 K. Brandt, Ann. Am. Acad. Polit. Sac. Sci., 225, 210-215 (1943). 



«« T. Shen, Science, 98, 302-303 (1943). 



«' P. E. Howe, Ann. Am. Acad. Polit. Soc. Sci., 225, 72-79 (1943). 



*^ Anonymous, Recommended Dietary Allowances, Food and Nutrition Board, Nat. 

 Research Council, Circ. No. 129, 3-31 (Oct., 1948), p. 17. 



