What is the effect of stress hormones like cortisol on metabolism?

The correct answer addresses the role of stress hormones, particularly cortisol, in metabolism and how they influence energy balance within the body. Cortisol is a glucocorticoid hormone that is released during times of stress and plays a significant role in several metabolic processes.

When cortisol levels rise, it leads to an increase in blood glucose levels by promoting gluconeogenesis, the process of generating glucose from non-carbohydrate sources in the liver. This is part of the body's fight-or-flight response, providing an immediate energy source to cope with stress. Additionally, cortisol can enhance fat metabolism to make energy available more rapidly.

Moreover, cortisol has complex effects on muscle tissue. While it does support the mobilization of energy substrates, it can lead to muscle catabolism over time if elevated levels persist chronically, as it promotes protein breakdown to release amino acids that can also contribute to glucose synthesis.

In summary, cortisol increases metabolism and influences both fat and glucose metabolism, providing an energy boost needed for short-term responses to stressors, thereby justifying why this option is the correct answer.