Research

Hormonal

In healthy lean men, the metabolic and neuroendocrine adaptations of the hypothalamic-pituitary-adrenal (HPA), renin-aldosterone, and growth hormone-IGF-1 axes during short-term fasting are independent of leptin levels.

Fasting affects different hormonal systems differently. While reproductive hormones drop due to low leptin, stress hormones (cortisol) and growth hormone changes happen regardless of leptin levels. Do not assume fixing leptin will fix all hormonal responses to starvation.

GoodRefutesHIGH confidence
In contrast to findings in mice, fasting-induced changes in the hypothalamic-pituitary-adrenal, renin-aldosterone, and growth hormone–IGF-1 axes as well as fuel utilization may be independent of leptin in humans.
Jean L. Chan et al. · Journal of Clinical Investigation · 2003

Why this rating

Same study design as N1; robust negation of effect for specific axes.

Source

The role of falling leptin levels in the neuroendocrine and metabolic adaptation to short-term starvation in healthy men

Jean L. Chan et al. · Journal of Clinical Investigation · 2003

DOI 10.1172/jci17490

crossover · n=8Cited 575×
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DOI resolved against Crossref · corpus check 2026-06-10

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