Which of the following measures enhances natural body defenses?

Promoting adequate sleep is essential for enhancing natural body defenses. Sleep plays a critical role in the immune system, aiding in the production of cytokines, which are essential for fighting infections and inflammation. When individuals receive sufficient rest, their body is better equipped to respond to pathogens, recover from illnesses, and maintain overall health.

In contrast, measures like encouraging a poor diet can lead to nutrient deficiencies that weaken the immune response. Increasing stress levels can have negative effects on immunity, as chronic stress is associated with higher levels of cortisol, which can suppress the immune system. Similarly, restricting fluid intake can lead to dehydration, which negatively impacts various bodily functions, including those necessary for optimal immune response. Thus, promoting adequate sleep is a key factor in strengthening the body's defenses against infectious agents.