Metabolism changes with age in multiple ways, primarily influenced by factors such as muscle mass, hormonal shifts, and activity levels. As individuals age, there is typically a decline in muscle mass and an increase in body fat, which can lead to a slower metabolic rate. This metabolic slowdown can affect energy expenditure and weight management. Additionally, hormonal changes, particularly involving insulin and thyroid hormones, can further influence how effectively the body processes energy. Maintaining an active lifestyle and a balanced diet can help mitigate these age-related metabolic changes.