Obesity 



WILDER TILESTON 



NEW HAVEN 



Definition 



Obesity may be defined as an excessive accumulation of fat in the body. 

 There is no sharp dividing line at which obesity begins, but in general 

 an increase of 15 per cent over the average weight for the height and 

 age may be considered within normal limits, while weight in excess of 

 this, justifies a diagnosis of obesity. Persons more than 50 per cent 

 over weight are highly obese. Of course, it is necessary to take into ac- 

 count the build of the patient and the amount of subcutaneous fat, as 

 determined by inspection and palpation. 



Physiological Considerations 



According to C. Voit, the human body normally contains about 18 

 per cent of fat. Animal fat consists of a mixture of tristearin, tripalmitin 

 and triolein, with a small amount of other glycerides. The proportions 

 vary not only in different animals, but in different parts of the same 

 animal, and somewhat with the composition of the food, but in general 

 each species has a fat of characteristic proportions. The fat of the tissues 

 is semi-fluid at the temperature of the body. 



Fat may be derived from the fat of the food, from the carbohydrates, 

 or from the proteins. The fat in the food is digested in the intestine, and 

 absorbed in the form of soaps. Bloor (a) has shown that only those fats are 

 absorbed which can be broken down to a water-soluble (or bile-soluble) 

 form while such substances as wool-fat and petroleum hydrocarbons (pet- 

 rolatum, etc.), which are not saponifiable, are not capable of absorption. 

 The soaps and fatty acids are resynthetized to triglycerids in the intestinal 

 wall, and absorbed chiefly through the lymphatics, about 70 per cent ap- 

 pearing in the chyle. Bloor found that by the time these products of fat 

 digestion have passed through the intestinal wall, they approximate the 

 composition of human fat. Thus if fats with a high melting point and low 



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