What is indicated by the need for fewer calories in elderly individuals?

The need for fewer calories in elderly individuals is primarily attributed to a decline in metabolic rate. As people age, their bodies undergo various physiological changes, including a decrease in muscle mass and an overall reduction in physical activity levels. This leads to a slower metabolism, meaning that the body requires fewer calories to maintain its energy balance.

Additionally, older adults may not be as active as younger individuals, further contributing to lower energy expenditure. With a slower metabolism and potentially lower activity levels, they do not need as many calories to meet their energy requirements compared to when they were younger. Therefore, option B accurately reflects the physiological changes that explain the reduced caloric needs of the elderly.

In contrast, increased physical activity would typically necessitate more calories, while higher appetite levels would suggest a need for more calories, and increased hydration needs relate to fluid intake rather than caloric requirements. Understanding the relationship between aging, metabolism, and caloric needs is essential for nutritional planning and care for the elderly.