248 A BIOMETRIC STUDY OF BASAL METABOLISM IN MAN. 



already drawn. 29 Here the application of the formulas to diabetics 

 serves merely as a particular example of a general method. 



It may not be out of place, however, to look at certain quantitative 

 aspects of the subject more closely. On examining the increments in 

 metabolism due to diabetes found by this method, we note that they 

 are on the average only about 11 per cent as compared with 15 to 20 

 per cent as asserted in earlier publications from the Nutrition Labora- 

 tory. 30 In partial explanation of this percentage difference we may 

 note that our prediction equation for men includes about 16 athletes. 

 This represents about 12 per cent of the whole control series. But in 

 a preceding illustration we have shown that athletes themselves have 

 a higher metabolism than normal men at large. Our reasons for 

 including athletes in our standard series have been given above. It 

 should be a fixed scientific principle that standards should not be 

 changed whenever convenience demands. 31 The inevitable conse- 

 quence of this inclusion of the athletes has been to reduce the per- 

 centage difference between diabetics and non-diabetics. In short, it 

 has made the comparison as disadvantageous as possible to the views 

 concerning diabetes long held at the Nutrition Laboratory. Notwith- 

 standing this fact, the validity of the general conclusions already 

 drawn is fully supported. 



A study of the individual entries in this table has considerable 

 value as indicating the limits of trustworthiness of conclusions from 

 single subjects even when compared with a standard control based on 

 large numbers. For example, had the one subject examined chanced 

 to be D the incautious clinician might have concluded that diabetes 

 decreases metabolism. Had the second subject chanced to be Q he 

 might have concluded that a defect of 12 calories in one case and an 

 excess of 21 calories in the other indicated no relationship at all 

 between diabetes and metabolism. Had V or R been the only subject 

 examined, a quite exaggerated impression of the influence of diabetes 

 might have been drawn, for these men show an excess of 25.1 and 

 28.7 per cent. It is only when a considerable number of pathological 

 cases are available for comparison with the standard that dependable con- 

 clusions concerning the influence of any disease can be drawn. This 

 principle is a fundamental one, and must be applied in all comparisons 

 of special groups with standard control series in all nutritional research. 



:9 Benedict and Joslin, loc. cit., p. 121. 



"Benedict and Joslin, Carnegie Inst. Wash. Pub. No. 136, 1910.. p. 193; also Carnegie Inst. 

 Wash. Pub. No. 176, 1912, p. 121. 



31 Criticism has been made from the Nutrition Laboratory of the Du Bois method of excluding 

 undersized individuals in obtaining their normal, and the specific statement has been made that 

 we should not compare standard normals based primarily upon robust, vigorous individuals 

 with emaciated, weak, under-weight diabetics. We still hold these criticisms to be valid, and we 

 have avoided them in the comparisons in table 102 by utilizing equations which enable one to 

 compare each diabetic with a standard value for an individual of like height, weight, and age. 

 But in determining the equations for these standard values we have included athletes among the 

 normals, even thowjh their inclusion has minimized the difference between diabetic and non-diabetic 

 individuals. 



