Factors that can influence a person's metabolism include age, gender, body composition, and physical activity levels. Generally, metabolism decreases with age due to muscle mass loss and hormonal changes. Men typically have a higher metabolic rate than women because they usually possess more muscle mass, which burns more calories. Additionally, higher levels of physical activity can boost metabolism by increasing muscle mass and overall caloric expenditure. Other factors, such as genetics and diet, also play a role in metabolism, influencing how efficiently the body converts food into energy.