What it means
After weight loss, hunger hormones often rise and calorie burn can fall a bit more than size alone predicts. Many researchers see this as the body pushing back toward its old weight.
Set point is a model, not a fixed number you can measure. Some scientists prefer the term "settling point" because diet, sleep, stress and environment all shape where weight settles.
This pushback helps explain why many people in GLP-1 trials regained a large share of lost weight after stopping the drug. It is a biology problem, not a willpower problem.
Some research suggests that keeping weight off for longer may help the body adapt to a new normal, but the evidence is still limited. Long-term follow-up studies are ongoing.
Why it matters
It frames why long-term plans and maintenance matter as much as the weight-loss phase.