Personal Health
Hormonal signals such as leptin and ghrelin adjust appetite and energy expenditure to oppose deviations from a defended weight.
Short-term mass changes from hydration or glycogen shifts do not indicate a true change in the defended weight and are corrected by homeostatic mechanisms.
Extended environmental or behavioral changes can gradually recalibrate the defended weight so the body adopts a new long-term target after sustained exposure.
Attempts to maintain a lower or higher weight typically trigger compensatory changes in metabolism and hunger that resist sustained large deviations.
