Research

Hormonal

Low leptin levels during fasting stimulate feeding and reduce energy expenditure to conserve energy stores, whereas high leptin levels in the overfed state inhibit food intake and increase energy expenditure.

Your body uses leptin to signal energy status. When you fast, leptin drops, triggering hunger and slowing metabolism to save energy. When you are overfed, leptin rises to curb appetite and burn more energy. In obesity, this system breaks down (leptin resistance), so high leptin levels fail to suppress appetite.

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Low leptin levels during fasting stimulate feeding, reduce energy expenditure, and modulate neuroendocrine and immune function to conserve energy stores. On the other hand, rising leptin levels in the overfed state prevent weight gain by inhibiting food intake and increasing energy expenditure.
Rexford S. Ahima et al. · Molecular Endocrinology · 2008

Why this rating

The paper is a comprehensive review by leading endocrinologists summarizing extensive evidence.

Source

Adipokines and the Peripheral and Neural Control of Energy Balance

Rexford S. Ahima et al. · Molecular Endocrinology · 2008

DOI 10.1210/me.2007-0529

narrative_reviewCited 310×
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DOI resolved against Crossref · corpus check 2026-06-10

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