GLOSSARY

Food Intake Regulation controls the amount and pattern of 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.

Eating responds to biological needs and to taste, availability, habit, emotion and reward. Craving a particular food is not a deficiency test for that food's nutrients. Hedonic and homeostatic influences can coexist rather than forming separate behaviors. In sport, restrictive eating, poor sleep or long meal gaps may also affect desire. Assessment should avoid moral labels and consider actual intake patterns rather than assigning every craving to one hormone.

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.

Some exercise, especially hard bouts, can temporarily suppress appetite, but the response varies across people and sessions. Ghrelin, PYY and GLP-1 changes do not have a simple guaranteed relationship with later intake. Lower appetite does not mean lower energy requirements. Athletes can use tolerable foods, smaller portions and workable timing to meet demand and monitor recovery rather than assuming a blunted hunger signal proves that refueling is unnecessary.

Low energy availability means insufficient energy remains after exercise for required bodily functions; it is not synonymous with low carbohydrate or weight loss alone. Problematic exposure can affect reproductive, thyroid, bone and appetite systems with variable patterns. Restoring supply and reviewing training load are central to assessment. One normal hormone or a universal numerical cutoff cannot confirm or exclude every case, so symptoms, history and clinical evaluation must be integrated.

Circadian rhythms relate to biological clocks, while observed daily patterns also reflect sleep, food and activity. Sleep loss can alter appetite and food choice, but ghrelin and leptin do not change in the same direction in every study. Meal timing should fit training and intake needs. One timing experiment is not a universal rule to omit dinner or fast every athlete; total intake, schedule and individual tolerance still matter.