Does Weight far from the balance zone cause infertility?

Established. A link with fertility is documented by numerous, converging human studies, endorsed by health authorities. Adipose tissue produces estrogens; in excess as in deficiency, it unbalances the cycle and lowers testosterone.

Weight far from the balance zone

Metabolism, adipose tissue

Evidence level : Established LifestyleMechanism : Hormonal disruption burden

🟢 A link with fertility is documented by numerous, converging human studies, endorsed by health authorities.

Where it's found: Significant overweight as well as marked thinness, rapid and recent weight gain or loss.
Suspected mechanism: Adipose tissue produces estrogens; in excess as in deficiency, it unbalances the cycle and lowers testosterone.
Suggested alternative: A moderate, sustained change (5 to 10%) already improves cycles. Very restrictive diets are counterproductive.
Source: ESHRE (European Society of Human Reproduction and Embryology); HAS (French health authority), obesity and fertility.

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Related factors

Including a factor does not mean it causes infertility: it is simply worth monitoring, depending on its level of evidence.

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Content last updated: September 14, 2026