ENDOCRINE ASPECTS OF OBESITY 61 
know that many thin persons of sedentary habits who 
eat excessive quantities of food and apparently digest 
it still do not put on weight. 
Obesity, of whatever type, is an expression of dis- 
turbed metabolism; and metabolism, we believe, is defi- 
nitely controlled by the glands of internal secretion. 
We recognize that the height of the skeleton is directly 
under the control of several of these glands and it 
seems more than likely that the weight also is governed 
by their activity. 
The problem is not a simple one, however, and re- 
quires much investigative effort. Even the relatively 
accurate determination of basal metabolism does not 
lend much aid, for investigators have shown that the 
basal metabolism of even very obese persons is practi- 
cally normal when measured by the heat-production per 
amount of body surface. Those estimations that are 
based on the measurement of heat-production per unit 
of weight and which show a lowered metabolism in 
obesity, obviously are incorrect, for as Benedict*® has 
pointed out, the fatty tissue is inert and does not affect 
the basal metabolism which “is a function of the total 
mass of active protoplasmic tissue.” 
Nearly every one of the endocrine glands has been 
named as producing a special type of obesity and we 
read of obesity of the genital and pituitary types or 
of thyroid, pineal, or adrenal origin. This has arisen 
through the fact that obesity often is associated with 
signs and symptoms which implicate dysfunction in dif- 
ferent ductless glands. The real condition in every case 
is one of pluriglandular dystrophy with the obesity as 
a feature common to them all. The most that can be 
said on the subject is that obesity is a disturbance of 
metabolism and metabolism is under the direct control 
of the ductless glands. Certain of these glands are 
known to be concerned more directly with the metabol- 
ism of carbohydrates and fats. 
