Set point
The weight range the body defends through appetite and energy-expenditure adjustments.
Set-point theory holds that the body defends a preferred weight range using upper and lower intervention points: cross the lower one and appetite rises while energy expenditure falls to push weight back up. Crucially, the defense against weight loss is stronger than against weight gain, which is why maintaining a reduced weight is biologically harder than gaining. GLP-1 medications can lower the defended range while taken; stopping tends to let the body push back toward its prior set point unless lifestyle counter-pressure is maintained.