The term for the rate at which the body burns calories at rest is called the Basal Metabolic Rate (BMR). BMR accounts for the energy required to maintain vital functions, such as breathing, circulation, and cell production, when the body is at rest. Factors like age, gender, and body composition can influence BMR. Understanding one's BMR is crucial for effective weight management, as it helps determine overall caloric needs and informs dietary planning to achieve fitness and health goals.