Hormonal

Administration of low-dose leptin reverses the adaptive reduction in energy expenditure and the decline in circulating thyroid hormones that occur as physiological responses to sustained weight loss.

If you have lost weight and feel your metabolism has slowed down permanently, this research suggests that your body's hormone levels (specifically leptin and thyroid hormones) may be driving this slowdown. While this specific study uses leptin injections, it highlights that metabolic slowdown after weight loss is a reversible hormonal state, not necessarily a permanent 'broken' metabolism. Consult a doctor about hormonal evaluations if you are struggling with metabolic adaptation post-weight loss.