How does metabolism change with age?

As individuals age, various physiological changes occur that generally lead to a slowdown in metabolic processes. This slowdown can be attributed to several factors, including a decrease in muscle mass, changes in hormonal levels, and alterations in energy expenditure. Muscle tissue is metabolically active and plays a crucial role in energy metabolism; as muscle mass decreases with age, the basal metabolic rate (BMR) tends to decline, resulting in lower energy expenditure even at rest.

Additionally, hormonal changes such as decreased levels of growth hormone and testosterone can further contribute to a reduction in metabolic rate. These changes may influence how efficiently the body processes nutrients and utilizes energy. Therefore, overall metabolic activity typically diminishes with age, making it essential for aging individuals to adjust their diet and physical activity levels to maintain a healthy weight and metabolic health.

In contrast, choices that suggest an increase in speed or efficiency of metabolism do not align with the evidence from metabolic studies on aging.