394 FAT METABOLISM. OBESITY 



will also give occasion to take up the matter of fatty acid 

 catabolism. It should only be added that Dakin, 33 who 

 hoped to imitate the oxidation reactions in the body by the 

 action of hydrogen peroxide, observed besides the oxida- 

 tion at the yS-carbon atom the same thing at the a-atom and 

 the catabolism of the /?-oxybutyric acid into not only diacetic 

 acid and acetone but also into acetic acid and formic acid: 



CH,.CH(OH).CH 2 .COOH 



S ^ 



CHa.CO.CHj.COOH CH 3 .COOH 



\ \ 



CH,.CO.CO, + CO, H.COOH + CO, 



I 

 CO, + H,0. 



Whether an analogous disintegration, as this just described, 

 is also to be thought of as physiological, is, however, at pres- 

 ent not known. 



Nature of Obesity. Here may be taken up briefly what 

 is known from the standpoint of the biochemist of the nature 

 of obesity. 



Common experience indicates that many persons who are 

 " disposed " toward corpulence accumulate fat even though 

 they do not ingest any more food apparently than do other 

 individuals ; in such cases one might suspect that there exists 

 a lowering of material exchange. A whole series of studies 

 upon metabolism in obesity are now at our disposal for 

 consideration. 34 Many authorities, as Jaquet and Svenson, 

 found, as a matter of fact, in corpulent persons a distinctly 

 lower increase in gas-interchange after ingestion of food 



88 H. D. Dakin (C. A. Herter's Lab., New York), Jour, of biol. Chem., 4, 

 77, 91, 227, 1908. 



4 Thiele and Nehring, 1896; Stuve, 1896; A. Magnus-Levy, 1897; C. von 

 Noorden, 1900; Jaquet and Svenson, 1900; Rubner, 1902; Reach, 1904; E. A. 

 v. Willebrandt, 1908; R. Stahelin, 1909; G. v. Bergmann, 1909; F. Umber, 

 1909. Literature on Metabolism in Obesity: C. v. Noorden, Die Fettsucht, 

 Nothnagel's Handb., Part 7, 1900; v. Noorden's Handb. d. Pathol. d. Stoffw., 

 2d ed., 2, 189-211, 1907; A. Jaquet, Ergebn. d. Physiol., 2', 553-554, 1903; 

 F. Umber, Lehrb. d. Ernahr. u. d. Stoffwechselkr., 73-117, 1909; G. von Berg- 

 mann Handb. d. Biochem., 4" 208-237, 1910. 



