Research

Hormonal

Leptin functions primarily as a starvation signal to conserve energy during caloric deficit, rather than as a long-term regulator of body weight in humans.

When you lose weight, your leptin levels drop faster than your fat mass, signaling 'starvation' to your brain. This triggers hunger and slows metabolism to protect your energy stores. This is a normal survival mechanism, not a failure. Recognizing this helps explain why weight loss can become difficult over time and why sustainable habits are key to managing these hormonal signals.

GoodQualifiesHIGH confidence
In conclusion, in humans, the leptin signaling system appears to be mainly involved in maintenance of adequate energy stores for survival during periods of energy deficit.
Eric Jéquier · Annals of the New York Academy of Sciences · 2002

Why this rating

Well-supported by the review of hormonal responses to fasting and weight loss.

Source

Leptin Signaling, Adiposity, and Energy Balance

Eric Jéquier · Annals of the New York Academy of Sciences · 2002

DOI 10.1111/j.1749-6632.2002.tb04293.x

narrative_reviewCited 788×
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DOI resolved against Crossref · corpus check 2026-06-10

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