nonfeeding

Nonfeeding is the condition in which an organism does not ingest food or refuses to feed. It can be a normal behavioral phase or a response to disease, injury, or environmental factors. In animals, nonfeeding may occur during specific life stages or physiological states, such as diapause, torpor, or metamorphosis, when feeding is temporarily suspended. It can also result from stress, capture, illness, or poor habitat conditions, and may be transient or prolonged depending on the underlying cause.

In humans and other animals under care, nonfeeding refers to the absence of oral intake. It may be voluntary, as during fasting or dietary restrictions, or involuntary, due to illness, nausea, dysphagia, mucositis, or unconsciousness. Assessment includes monitoring intake, appetite, weight, hydration, and biochemical status. When oral intake is unsafe or insufficient, alternative nutrition support, such as enteral feeding via a tube or parenteral nutrition, may be provided.

Feeding behavior is regulated by neural circuits and hormones, including ghrelin, leptin, and various neuropeptides, with external factors such as taste, smell, social context, and stress influencing decisions to eat. Nonfeeding is of interest in fields ranging from physiology and welfare to clinical care, nutrition science, and wildlife management.

Consequences can range from minor vulnerability to energy deficits in short episodes to severe malnutrition and dehydration with prolonged nonfeeding. In wildlife and captive populations, the timing and duration of nonfeeding affect survival, growth, and reproduction; in clinical settings, it can influence recovery and outcomes.

See also: appetite, fasting, anorexia, feeding behavior, nutrition support.