The Claim

Insulin significantly reduces skeletal muscle protein breakdown by an average of 15.46 nmol (100 ml leg vol.)⁻¹ min⁻¹ in healthy humans under controlled experimental conditions, independent of amino acid availability, indicating its primary anabolic role is anti-catabolic rather than stimulatory of synthesis.

Source: Role of insulin in the regulation of human skeletal muscle protein synthesis and breakdown: a systematic review and meta-analysis

What the research says

Supports is higher

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

Supports
44score
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 healthy humans, insulin directly lowers the rate of muscle protein breakdown by 15.46 nmol per 100 ml of leg volume per minute, regardless of amino acid levels, showing its main effect on muscle is to prevent breakdown rather than to build new protein.

See the scientific wording

Insulin significantly reduces skeletal muscle protein breakdown by an average of 15.46 nmol (100 ml leg vol.)⁻¹ min⁻¹ in healthy humans under controlled experimental conditions, independent of amino acid availability, indicating its primary anabolic role is anti-catabolic rather than stimulatory of synthesis.

Why this might work

Insulin binds to muscle cells and turns on a signaling chain that shuts down the cellular machinery responsible for breaking down proteins. This stops muscle proteins from being destroyed, even when no extra amino acids are present.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Role of insulin in the regulation of human skeletal muscle protein synthesis and breakdown: a systematic review and meta-analysis

    Insulin doesn't make muscles grow bigger on its own, but it does stop them from breaking down — and this study proves it, even when protein levels in the blood stay the same.

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

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

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