GLOSSARY

Ghrelin is a mainly gastric peptide linked to appetite and growth-hormone secretion.

Ghrelin arises mainly from the stomach, and its acylated form activates the classical ghrelin receptor. Des-acyl ghrelin should not be assumed to be an identically acting hunger hormone; its biology and measurement differ. Concentrations often vary around meals but do not fully explain hunger. Sample handling and whether total or acylated ghrelin was measured matter when comparing exercise studies or linking laboratory changes to actual food intake.

Appetite is desire to eat, distinct from hunger, gastric fullness and actual energy requirements. Satiety concerns suppression between meals, whereas satiation helps end the current meal. A person can feel full while still under-fueled. Recording sensations, actual intake and activity timing together supports planning better than drawing conclusions from one sensation or hormone; subjective scales and food records measure different aspects rather than interchangeable biological quantities.

Nutrient entry, gastric distension and neural and hormonal signals jointly regulate eating. GLP-1, PYY and CCK are important, but one blood rise cannot precisely predict later intake. Molecular form, receptor and vagal or central routes matter. In athletes, strong fullness from low-energy bulky meals can make adequate fueling difficult, so portions and timing should fit actual demand and tolerance rather than pursuing maximal appetite suppression.