Optimizing Composition of Defined Control Diets and Exercise for Ideal Metabolic Health in Laboratory Mice

In the U.S., nutrient deficiencies, obesity and metabolic syndrome are all current public health concerns affecting millions of people. Fundamental dietary research approaches addressing these important areas are typically based on research in laboratory animals that are fed chemically defined diets to learn about the impacts of dietary components or supplements of interest on metabolic health. All such feeding trials are faced with the problem that a healthy standard diet must be established to ensure optimal metabolic health of the control animals. The AIN-93G standard diet is commonly used as a chemically defined control diet in feeding trials. Furthermore, researchers have used the AIN-93G diet as a model for chemically defined diets that exhibit similar macro and micronutrients. However, chemically defined diets modeled after the AIN-93G diet have been found to induce obesity in laboratory animals. Therefore, the purpose of this study was to determine an effective dietary formulation of chemically defined diets to maintain metabolically health control mice for research trials. Three parameters of diet composition: protein percentage, carbohydrate complexity, and calorie density were altered to determine the impact on metabolic health of animals. Additionally, we evaluated to what extent, voluntary physical exercise can offset the obesogenicity of the control diet modeled after the AING-93 standard control diet. Through a series of metabolic function tests, the results demonstrated that calorie density had a significant impact on the metabolic parameters that were assessed. Furthermore, voluntary physical exercise significantly improved metabolic health even when animals were fed a diet with obesogenic potential. The outcomes of this study highlight the necessity to improve chemically defined control diets used in metabolic studies of nutritional deficiencies and metabolic diseases like obesity