The effect of aging on metabolism is a gradual decline in metabolic rate. As people age, their bodies typically experience a reduction in muscle mass and hormonal changes, which can contribute to a slower metabolism. This decline can result in increased difficulty in maintaining or losing weight. Additionally, older adults may require fewer calories yet still need adequate nutrition to support health. Regular physical activity, especially strength training, is vital for counteracting age-related metabolic decline by preserving muscle mass and enhancing metabolic function.