Which subsystem in Johnson's model specifically addresses how and when persons eat?

The ingestive subsystem in Johnson's model focuses specifically on how and when individuals consume food. This subsystem emphasizes the behaviors and processes related to the intake of nutrients necessary for survival and health. It encompasses not just the act of eating but also the timing, preferences, and cultural factors that influence individuals' eating habits. The significance of this subsystem lies in its recognition that nutrition is vital to maintaining overall health and supporting the other subsystems within Johnson's nursing model.

In contrast, the other subsystems—eliminative, dependent, and achievement—address different aspects of human functioning. The eliminative subsystem focuses on the processes involved in the expulsion of waste, while the dependent subsystem addresses individuals’ needs for assistance and support from others. The achievement subsystem is concerned with personal goals and accomplishments. Each subsystem contributes to a holistic understanding of a person's health, but the ingestive subsystem is explicitly centered on the intake of food.