The claimEvidence A · guideline-tier
Leptin injections will make you thin
The evidence
Heymsfield 1999 JAMA: leptin is already elevated in common obesity (resistance), so exogenous leptin is ineffective. Only the rare congenital leptin-deficiency patients respond.
The mechanism, in brief
Leptin was discovered in 1994 by Friedman's lab — a hormone secreted by adipose tissue, the long-term signal that fat tells the brain about energy reserves. This overturned the old view that fat was just a passive warehouse and formally established adipose as an endocrine organ.
Sources (1)
- Heymsfield, S. B., Greenberg, A. S., Fujioka, K., Dixon, R. M., Kushner, R., Hunt, T., Lubina, J. A., Patane, J., Self, B., Hunt, P., & McCamish, M. (1999). Recombinant leptin for weight loss in obese and lean adults: A randomized, controlled, dose-escalation trial. JAMA, 282(16), 1568–1575.