The Claim

During caloric restriction and refeeding in rats, skeletal muscle exhibits reduced net synthesis of tri-iodothyronine (T3) from thyroxine (T4), with an 18% decrease after restriction and a 14% decrease after refeeding, associated with increased expression of deiodinase type 3 (DIO3) and decreased expression of deiodinase type 2 (DIO2).

Source: Caloric restriction induces energy-sparing alterations in skeletal muscle contraction, fiber composition and local thyroid hormone metabolism that persist during catch-up fat upon refeeding

What the research says

Supports is higher

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

Supports
14score
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.

How it works
1 study reviewed
In plain English

In rats undergoing periods of reduced food intake followed by refeeding, skeletal muscle produces less active thyroid hormone T3 from its precursor T4, with measurable reductions of 18% after restriction and 14% after refeeding, corresponding to increased levels of the enzyme that inactivates T3 and decreased levels of the enzyme that activates it.

See the scientific wording

During caloric restriction and refeeding in rats, skeletal muscle exhibits reduced net synthesis of the active thyroid hormone tri-iodothyronine (T3) from its precursor T4, with a 18% decrease after restriction and 14% decrease after refeeding, linked to increased expression of the inactivating enzyme DIO3 and decreased expression of the activating enzyme DIO2.

Why this might work

When food intake drops and then returns, muscle cells produce less of the active thyroid hormone T3 because they make more of an enzyme that destroys T3 and less of an enzyme that creates it. This lowers T3 levels inside the muscle, which slows down muscle contraction and relaxation, reducing energy use and helping the body store fat.

Verified mechanismbased on 1 study

What the research says

1 study

  1. Study: Caloric restriction induces energy-sparing alterations in skeletal muscle contraction, fiber composition and local thyroid hormone metabolism that persist during catch-up fat upon refeeding

    When rats eat less and then eat more again, their muscles make less of the active thyroid hormone T3 because the enzyme that breaks it down increases and the one that makes it decreases—this helps their bodies save energy and gain fat faster.

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

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