Final answer:
The metabolic rate, specifically the basal metabolic rate (BMR), is influenced by factors such as body composition, physical activity, time of day, and food intake.
Step-by-step explanation:
The rate at which the body uses food energy to sustain life and perform activities is called the metabolic rate. The metabolic rate, specifically the basal metabolic rate (BMR), is affected by various factors such as body composition, physical activity, time of day, and food intake. For example, body composition, including muscle mass and body weight, can impact the BMR. Additionally, physical activity can increase the BMR by building lean tissue, while food intake can provide the energy needed to support the body's functions.