Our goal is to develop mathematical models that quantify the dynamic fluxes of energy metabolites during obesity development and weight loss periods in rodents. The models would also predict energy intake, body weight, and composition under various dietary circumferences.
Obesity, once established, is difficult to reverse in humans. My research team completed a feeding study in C57BL/6 mice and found that obesity arising from temporary exposure to obesigenic diets led to a persistent state of obesity after the obesigenic diet was removed. Qualitatively, it is clear that obesity results from a prolonged period where food intake exceeds energy expenditure. However, researchers have not been able to clearly and quantitatively integrate data on various aspects of energy metabolism, food intake, and body composition changes to better understand the mechanisms responsible for the development and persistence of obesity. My research is focused on building mathematical models of energy metabolism and body composition dynamics in C57BL/6 mice. I developed a novel computational methodology to demonstrate how energy intake, energy expenditure, and fuel selection are interrelated and give rise to observed changes in body weight and body composition in lab mice. Based on this methodology, I developed a mathematical model that predicts the changes of body weight and composition in lab mice, given their food composition and energy intake. Such a model helps us to better understand our own data on body weight regulation in lab mice. It will also serve as a general utility for other investigators studying various mouse models of body weight regulation.
The proposed models will be vigorously evaluated with the latest data from published studies to identify weaknesses and to make improvements accordingly. Presently, the proposed model does not explicitly include the effects of hormones and obesity-related genes, although these are implicitly included in the model parameters. Future work will explicitly account for those effects and will extend the model to rats and other strains of mice. Such a model could be used to compare experiment results between mice and rats, or even between different mouse strains and genetically-engineered animal models.