A deficiency of estrogen (female sex hormones) can be a cause of underweight in people of any sex.
NOT BSTOTAL BS
TOTAL BS — Verdict: False
Verified by Lenz ·
The Short Version
The evidence does not support estrogen deficiency as a cause of underweight. In the stronger medical literature, low estrogen is more often linked to increased fat mass and weight gain, while underweight and calorie deficiency commonly cause low estrogen by suppressing reproductive hormone function. The claim reverses the usual direction of causation and overgeneralizes across sexes.
Caveats
Correlation does not establish causation: underweight often leads to low estrogen, especially in energy deficit and anorexia nervosa.
Most high-quality sources link estrogen deficiency to higher fat mass or weight gain, not underweight.
Broad wording such as "in people of any sex" is unsupported by the evidence and makes the claim materially misleading.