Spontaneous obesity in maturing squirrel monkeys fed semipurified diets

Area of Science:

• Primate physiology
• Nutritional science
• Obesity research

Background:

• Squirrel monkeys are typically lean primates (5-10% body fat).
• Weight gain and obesity can occur in squirrel monkeys fed semipurified diets high in fat and sucrose.
• Obesity is conventionally defined as body weight exceeding 1,200 g for males and 800 g for females.

Purpose of the Study:

• To investigate the development of obesity in squirrel monkeys fed palatable diets.
• To characterize the body composition and weight gain patterns in obese squirrel monkeys.
• To explore the role of food intake and potential contributing factors to obesity in this species.

Main Methods:

• Monitoring body weight and food intake in squirrel monkeys fed different diets.
• Analyzing carcass composition of obese animals.
• Observing weight cycling patterns.

Main Results:

• Squirrel monkeys fed semipurified diets with moderate fat and sucrose developed significant obesity by 6 years of age.
• Obese animals exhibited fat content ranging from 18% to 40%.
• Hyperphagia (excessive food intake) was associated with rapid weight gain, suggesting a link between diet palatability and obesity development.

Conclusions:

• Palatable diets interact with the neuroendocrine system to promote obesity in squirrel monkeys.
• Dietary factors play a crucial role in the development of obesity in this primate model.
• Further research into the neuroendocrine mechanisms underlying diet-induced obesity in squirrel monkeys is warranted.