AJP - Regulatory, Integrative and Comparative Physiology, Vol 241, Issue 5 316-R321, Copyright © 1981 by American Physiological Society
Spontaneous obesity in maturing squirrel monkeys fed semipurified diets
L. M. Ausman, K. M. Rasmussen and D. L. Gallina
The squirrel monkey is usually a lean primate (5-10% fat) until the onset
of the pubertal growth spurt at about 3 yr of age. This characteristic is
generally maintained thereafter for animals fed commercial monkey biscuits.
Animals fed semipurified diets containing a moderate amount of fat and
sucrose continue to gain weight, however, until a frank obesity is
developed. Conventionally, an animal is labeled obese when the body weight
is greater than 1,200 and 800 g for males and females, respectively. By 6
yr of age, practically 100% of the animals satisfy these criteria. The
carcass composition from a subset of obese animals showed that fat content
ranged from 18 to 40%, and that weight gain in males heavier than 800 g
represents increasing proportions of fat. The annual weight cycling
ascribed to sexual activity appeared to remain superimposed on the "basal"
obesity. Food intake monitoring showed a significant hyperphagia associated
with rapid weight gain. A major interaction between the neuroendocrine
setting and a very palatable diet in the development of this syndrome is
implied.
