The Claim

Ten days of total energy deprivation in healthy, normal-weight males is associated with early and marked reductions in blood triiodothyronine (T3) levels and increases in reverse T3 (rT3) levels, with rapid return to baseline after refeeding.

Source: Effects of total energy withdrawal (fasting) on thelevels of growth hormone, thyrotropin, cortisol, adrenaline, noradrenaline, T4, T3, and rT3 in healthy males.

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
21score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Correlation
1 study reviewed
In plain English

In healthy, normal-weight men, ten days of complete fasting causes a significant drop in triiodothyronine (T3) and a rise in reverse T3, and these changes reverse quickly when eating resumes.

See the scientific wording

Ten days of total energy deprivation in healthy, normal-weight males is associated with early and marked reductions in blood triiodothyronine (T3) levels and increases in reverse T3 (rT3) levels, with rapid return to baseline after refeeding, suggesting a metabolic adaptation to conserve energy during fasting.

Why this might work

When no food is consumed, the brain detects low energy and reduces signals that activate the thyroid gland. This causes the body to stop converting the main thyroid hormone into its active form and instead produce an inactive version. The active hormone drops, the inactive one rises, and the body uses less energy. When eating resumes, this switch reverses immediately.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Effects of total energy withdrawal (fasting) on thelevels of growth hormone, thyrotropin, cortisol, adrenaline, noradrenaline, T4, T3, and rT3 in healthy males.

    When healthy men don't eat for 10 days, their bodies slow down their metabolism by lowering the active thyroid hormone and raising the inactive kind, so they use less energy. As soon as they start eating again, everything goes back to normal.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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