Research

Hormonal

Overnutrition reduces whole-body energy expenditure by impairing peripheral T4-to-T3 conversion via decreased D2 activity, rendering obese individuals resistant to T4 therapy.

Obesity impairs your body's ability to convert T4 into active T3, which lowers your metabolism and makes T4 supplements less effective for weight loss. The solution is not more thyroid medication, but weight loss, which restores normal thyroid function.

GoodSupportsHIGH confidence
Overnutrition additionally suppressed T4 activation, rendering the mice resistant to T4 and reducing EE.
Jessica Rampy et al. · bioRxiv (Cold Spring Harbor Laboratory) · 2025

Why this rating

Strong mechanistic data in mice, with human translational hints.

Source

Overnutrition directly impairs thyroid hormone biosynthesis and utilization, causing hypothyroidism, despite remarkable thyroidal adaptations

Jessica Rampy et al. · bioRxiv (Cold Spring Harbor Laboratory) · 2025

DOI 10.1101/2025.03.31.645596

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DOI resolved against Crossref · corpus check 2026-06-10

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