Two directions, one integratorEvery signal below is read by the hypothalamus, which adds them up. Orexigenic signals raise hunger; anorexigenic signals raise fullness. Most are made in the gut and act within a meal; leptin and insulin report your longer-term fuel stores.
Read the model honestly. The directions — leptin falls, ghrelin rises, energy use drops below what a smaller body predicts — are well established. The exact magnitudes vary widely by person and study; the numbers here are an illustrative example built on a 2,400 kcal/day sample maintenance level, not a prediction for any individual. This describes physiology; it is not medical or dietary advice.