Fullness

Fullness refers to the state of being filled to capacity or to a sense of abundance or completeness. It can describe a physical container that has no space left, a space that is fully occupied, or a metaphorical condition such as emotional or spiritual wholeness. In everyday language, fullness most often describes satiety after eating, or the sense that a period or experience has reached completion.

In human physiology, fullness after a meal results from stomach distension and a complex hormonal signaling network. Stretch receptors in the stomach signal the brain via the vagus nerve, while hormones such as cholecystokinin (CCK), peptide YY (PYY), and glucagon-like peptide-1 (GLP-1) promote satiety and reduce appetite. These signals help regulate meal size and energy intake. Individual differences in digestion, metabolism, and eating behavior influence perceived fullness.

Fullness also carries qualitative meanings beyond the physical. It can denote abundance or sufficiency in resources or experiences, as in fullness of life, or a sense that a work of art expresses wholeness. In philosophy and theology, fullness may refer to perfection, completeness, or the realization of potential.

In measurement and study, fullness can be assessed with subjective scales such as self-reported satiety ratings, and, for physical capacity, by the remaining available space in a container or cavity. The concept appears across disciplines including nutrition, psychology, design, and the arts.