Spontaneous obesity in maturing squirrel monkeys fed semipurified diets

monkeys fed semipurified diets. Am. J. Physiol. 241 (Regula-tory Integrative Comp. Physiol. 10): R316-R321, 1981.-The squirrel monkey is usually a lean primate (5-l@ % 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. Con-ventionally, an animal is labeled obese when the body weight is greater than 1,200 and 800 g for males and females, respec-tively. 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 increas-ing proportions of fat. The annual weight cycling ascribed t